Professor Ajayan Vinu

This chapter discusses recent trends and advances of mesoporous molecular sieve in catalysis and also highlights the potential of these catalysts particularly in the field of organic reactions, which properly modified mesoporous catalysts are capable to catalyze. Successful synthesis of mesoporous molecular sieves has opened a new fascinating research area in inorganic chemistry strongly connected with organometallic chemistry and solid state chemistry and has potential applications in adsorption, drug delivery and catalysis. Mesoporous molecular sieves doubtless accelerated the development of new interesting catalysts in acid, base, and redox catalysis. In addition, large surface areas together with pore sizes in mesopore range enable the immobilization of highly active and selective homogeneous catalysts. Examples of mesoporous molecular sieves-involving acid-catalyzed reactions, hydrodesulfurization, metathesis, hydroxyalkylations, and C-C bond forming reactions (Heck reaction or Suzuki reaction) have been provided in the chapter. Activity of synthesized catalysts strongly depends on the type of mesoporous support under investigation, way of its modification, interaction of active species with the surface, and reaction conditions. Catalytic systems based on mesoporous silica or alumina supports modified with transition metal oxides for hydrodesulfurization (MoO3) and metathesis of olefins and unsaturated esters have also been discussed in this chapter. © 2009 Elsevier B.V. All rights reserved.

Xenes are increasingly pivotal in various applications; particularly, black phosphorene (BP) has recently drawn profuse attention for its tremendous potential in electronics, spintronics, optoelectronics, and energy storage. However, its direct synthesis via bottom-up approaches remains elusive, largely burdened by cumbersome chemistry protocols. Herein, we report a novel large-scale, solution-phase synthesis approach of BP, in which concentrated orthophosphoric acid quickly turns to BP when exposed to microwave irradiation (~800 W, cumulative ~10 min consisting of 20 s pulses). While graphene/BP and MoS2/BP heterolayers exhibit metallic and diodic behaviors, respectively, graphene/boron nitride/BP sandwich device displays excellent tunneling (~20 mA). Interestingly, MoS2-BP hybrid delivers a capacitance of 1,698.8 F g-1, whereas graphene-BP exhibits a larger volumetric current density and a high capacitance of 2,863.5 F g-1 with sustainable reversibility, high load, and high rate capability up to 50 mV s-1. This synthesis provides a universal approach for large-scale production of 2D materials, thereby fueling future advancements in energy storage technologies.

Despite significant advancements in medical technology, cancer remains the world's second-leading cause of death, largely attributed to late-stage diagnoses. While traditional cancer detection methodologies offer foundational insights, they often lack the specificity, affordability, and sensitivity for early-stage identification. In this context, the development of biosensors offers a distinct possibility for the precise and rapid identification of cancer biomarkers. Carbon nanomaterials, including graphene, carbon nitride, carbon quantum dots, and other carbon-based nanostructures, are highly promising for cancer detection. Their simplicity, high sensitivity, and cost-effectiveness contribute to their potential in this field. This review aims to elucidate the potential of emerging carbon-nanomaterial-based biosensors for early cancer diagnosis. The relevance of the various biosensor mechanisms and their performance to the physicochemical properties of carbon nanomaterials is discussed in depth, focusing on demonstrating broad methodologies for creating performance biosensors. Diverse carbon-nanomaterial-based detection techniques, such as electrochemical, fluorescence, surface plasmon resonance, electrochemiluminescence, and quartz crystal microbalance, are emphasized for early cancer detection. At last, a summary of existing challenges and future outlook in this promising field is elaborated.

Nitrogen-rich carbon nitrides are desired materials for base-catalysed transformations; however, their synthesis is challenging due to the volatile nature of N at high temperatures. Herein, we report on the temperature-controlled synthesis of ordered N-rich mesoporous carbon nitrides (MCNs) via pyrolysis of aminoguanidine by using SBA-15 as a hard template. The properties and the nitrogen content of the materials were tuned by varying the carbonization temperature in the range of 350¿500 °C. At 350 and 400 °C, higher amounts of N could be retained in the MCN framework with the predominant formation of C3N6 having a six-membered aromatic ring with diamino-s-tetrazine moiety, whereas C3N5 with 1-amino/imino-1,2,4-triazole moieties was produced at 450 and 500 °C. The base catalytic activity of MCNs in Knoevenagel condensation of benzaldehyde with malononitrile revealed that the MCN-400 exhibited the highest catalytic performance by displaying a 96.4 % product yield with toluene as a solvent. The superior catalytic activity of MCN-400 is attributed to high N content (62.6 wt%), high surface area (235 m2 g-1), and large pore volume (0.74 cm3 g-1). The optimum temperature for obtaining the highest yield of the products is 80 °C, and the catalyst showed good cycling stability for 5 consecutive cycles.

Mesoporous silica-based materials are currently being explored as a new type of bioscaffold for bone regeneration applications. Zinc(Zn)¿ion incorporation is shown to play an important role in promoting bone regeneration and also providing antimicrobial activity to the scaffold materials. In this work, the role of pore size, geometry, and ordered structure on the Zn loading and release performance of two different mesoporous silica, SBA-1 and SBA-15, are compared. Zn loading is varied from 2.5 to 10 wt% for both samples, and its effect on the antibacterial and osteogenic activity is evaluated. Zn loading up to 10 wt% has a negligible effect on the morphology and textural properties of the mesoporous silica samples. The inductively coupled plasma mass spectrometry (ICP-MS) analysis reveals that SBA-15 exhibits significantly higher Zn release in Luria-Bertani (LB) broth as compared to SBA-1 that is reflected in the higher antibacterial activity of SBA-15 against both gram-positive and gram-negative bacteria. Various assays show that 5 wt% Zn loading is sufficient to produce both bactericidal and inhibitory effects on bacterial cells. The 5 wt% Zn-loaded samples induce osteogenic differentiation ofavianized bone marow-derived stromal cells (TVA-BMSCs) though SBA-15 samples show better compatibility compared to SBA-1, suggesting that Zn incorporation can produce sufficient antibacterial effect and osteogenic differentiation of TVA-BMSCs.

Metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs) are constituting two new classes of highly crystalline advanced permeable materials that have purchased significant courtesy due to their incredible characteristic such as large surface area, highly ordered pores/channels, and controllable crystalline structure. However, the main hurdles to their various applications in photocatalytic activity and novel energy storage/conversion devices are their low structural stability and electrical conductivities. Therefore, substantial research has been directed to maximize their advantages and mitigate the shortcomings of these fascinating materials. In this review article, we first introduced the background and brief timeline of COF/MOF development and notable milestones followed by a systematic overview of the different synthetic procedures and recent achievements and milestones of their applications in CO2 reduction, hydrogen production, lithium-ion batteries (LIBs), and supercapacitors (SCs). Finally, the challenges and future perspectives on further developing high-performance COF/MOF materials for photocatalysis and electrochemical energy storage application are discussed.

The development of versatile mesoporous silica nanomaterials (MSNSs) with suitable textural properties is essential for the targeted and precise delivery of therapeutic drugs for the treatment of various diseases. Especially, loading of highly toxic platinum-based drugs is essential to reduce their toxic side effects. However, loading platinum-based drugs such as carboplatin in high quantity in porous materials is extremely challenging owing to the high hydrophobicity and lack of functional groups for interacting with surfaces of MSNS. In this study, we report a facile synthesis of core-shell MSNS by employing a unique combination of triple surfactants - pluronic P123, cetyltrimethylammonium bromide (CTAB) and fluorocarbon-4 (FC-4) for targeted delivery of the carboplatin for the treatment of lung cancer. The highly hydrophobic FC-4 plays a vital role in tuning the self-assembly and thereby controls the size, morphology, textural properties and uniform pore size distribution of the MSNS. The optimised MSNS with the size range of 300¿320 nm, uniform size distribution, high surface area and ordered structure was successfully synthesised. A high drug loading of 26.7% was achieved on both bare and amine functionalised MSNS with a steady release of up to 60% and 37%, respectively, in PBS. The targeting efficiency of the folic acid functionalised particles was established by confocal microscopy, which showed higher cellular uptake of these particles in A549 cells. The high carboplatin loading and targeting ability resulted in high cytotoxicity from the folic acid functionalised and drug-loaded MSNS samples in PC9 cells compared to non-targeted and bare MSNS samples. Overall, this study proposes a new single-step synthesis of core-shell MSNS with high drug loading capacity that can be used to deliver drugs in treating different types of cancers.

We report on the catalytic activity of ordered mesoporous aluminosilicate, AlSBA-1 with 3D cage type porous structure, in the isopropylation of naphthalene (NP). The higher isopropylates: triisopropylnaphthalene (TriIPN) and tetraisopropylnaphthalene (TetIPN) isomers were formed over AlSBA-1 in addition to isopropylnaphthalene (IPN) and diisoprpylnaphthalene (DIPN) isomers. The higher isopropylates were started to form at 225 °C as primary products, which were produced by multi-step isopropylation from NP occurred during one stay on the catalytic site cooperated with the propene adsorbed neighbor acid sites. TriIPN isomers were composed of four isomers (1,3,7-. 1,3,5-, 1,3,6-, and 1,4,6-) formed from DIPN isomers. These formations of TriIPN isomers are controlled by the distribution of DIPN isomers. ß,ß-DIPN isomers lead to a,ß,ß-TriIPN isomers, and a,a-DIPN to a,a,ß-TriIPN, respectively. However, a,ß-DIPN isomers give both of a,a,ß- and a,ß,ß-TriIPN isomers depending on the reaction conditions. The distribution of TriIPN isomers is operated by their kinetic and thermodynamic properties. Bulky and unstable a,a,ß-TriIPN isomers (1,3,5- and 1,4,6-) were predominant at low temperatures, 175¿250 °C, and at low NP/Cat ratio at 250 °C, where the catalysis mainly proceeded under kinetic control. However, the formation of slim and stable a,ß,ß-TriIPN isomers (1,3,7- and 1,3,6-) increased with raising the temperatures, and was primary at 300 °C, where the catalysis occurred under thermodynamic control. From these results, it is concluded that the isopropylation of NP over AlSBA-1 occurs under kinetic and/or thermodynamically controls based on the reactivity of the reactants and the stability of the products, and no steric control concerns by mesopores.

Starting from sterically encumbered 2,6-di-tert-butylphenyl phosphate (dtbppH2) and co-ligand 3,5-dimethyl pyrazole (dmpz), it is possible to isolate either mono-, di- or tetranuclear copper phosphates by varying the copper source and making attendant changes in the reaction conditions. For example, reaction of copper nitrate with dtbppH2 and dmpz at 60 °C leads to the isolation of the mononuclear copper phosphate [Cu(dtbppH)2(dmpz)(MeOH)2] (1) as the only product. However, the use of copper acetate in place of copper nitrate and conducting the reaction at the room temperature leads to the formation of both dinuclear [Cu(dtbpp)(dmpz)2]2 (2) and tetranuclear [Cu2(dtbpp)(dmpz)2(OAc)(MeO)]2 (3) from the same reaction mixture. Compounds 2 and 3 could be isolated in pure form through fractional crystallization. Copper phosphates 1¿3 have been characterized by both analytical and spectroscopic methods including EPR and magnetic measurements. The molecular structures of all three compounds were established through single crystal diffraction studies. Dc magnetic measurements indicate antiferromagnetic interactions between the metal centres in all the compounds.

The rapid growth in electronic and portable devices demands safe, durable, light weight, low cost, high energy, and power density electrode materials for rechargeable batteries. In this context, biomass-based materials and their hybrids are extensively used for energy generation research, which is primarily due to their properties such as large specific surface area, fast ion/electron kinetics, restricted volume expansion, and restrained shuttle effect. In this review, the key advancements in the preparation of biomass derived porous carbons using different synthesis strategies and their modifications with species such as heteroatoms, metal oxides, metal sulfides, silicon, and other carbon forms are discussed. The electrochemical performances of these materials and the ion storage mechanisms in different batteries including lithium-ion, lithium¿sulfur, sodium-ion, and potassium-ion batteries are discussed. Special attention will be paid to the challenges in using porous biomass-derived carbons and the current strategies employed for maximizing the specific capacity and lifetime for battery applications. Finally, the drawbacks in current technology and endeavors for the future research and development in the field to catapult the performances of the biomass derived materials in order to equip them to meet the demands of commercialization are highlighted.

Non-small cell lung cancer (NSCLC) is a life-threatening cancer associated with a higher mortality rate. Despite promising results shown by combination therapies, there remains a need for efficient drug delivery materials capable of combining various drugs, imaging agents, and targeting agents to enhance treatment efficacy. In this study, we present the synthesis of novel core-shell hollow mesoporous silica nanoparticles (@MSN) with bimodal porosity and a large surface area (694 m2/g) to facilitate targeted drug delivery for NSCLC treatment. The hollow core-shell structure enables the loading of a substantial quantity of the pemetrexed drug, up to 839 µg/mg, with a sustained release of 20% within 48 h. The MSN is surface functionalised with amino and carboxyl groups to accommodate an imaging agent and facilitate the attachment of the targeting drug bevacizumab. These particles exhibit rapid uptake by both A549 and PC-9 cells. Moreover, the targeting by bevacizumab leads to higher cytotoxicity within 48 h and induces apoptosis more effectively than the non-functionalised samples. As a versatile drug delivery platform, the hollow core-shell MSN demonstrated in this study holds great potential for various drug delivery applications.

With increasing global climate change, integrated concepts to innovate sustainable structures that can multiaxially address CO2 mitigation are crucial. Here, we fabricate a functional wood structure with enhanced mechanical performance via a top-down approach incorporating a high-performance metal-organic framework (MOF), Calgary framework 20 (CALF-20). The functional wood with 10% (w/w) CALF-20 can capture CO2 with an overall gravimetric capacity of 0.45 mmol/g at 1 bar and 303 K that scales linearly with the MOF loading. Interestingly, the functional wood surpasses the calculated normalized adsorption capacity of CALF-20 stemming from the mesoporous wood framework, pore geometry modulation in CALF-20, and favorable CO2 uptake interactions. Density functional theory (DFT) calculations elucidate strong interactions between CALF-20 and the cellulose backbone and an understanding of how such interactions can favorably modulate the pore geometry and CO2 physisorption energies. Thus, our work opens an avenue for developing sustainable composites that can be utilized in CO2 capture and structural applications.

Due to its high energy density and non-polluting combustion, hydrogen has emerged as one of the most promising candidates for meeting future energy demands and realising a C-free world. However, the wider application of hydrogen is restricted by issues related to the generation, storage, and utilisation. Hydrogen production using steam reforming leads to CO2 emissions, storage of hydrogen requires extreme conditions, and utilisation of hydrogen needs to be highly efficient. Solid materials, can play significant roles in hydrogen sector as these materials are appropriate for the effective generation, storage, and utilisation of hydrogen. Their physical, chemical, thermal, and electronic properties can be easily manipulated to enhance their efficiencies in all three areas. In this review, various materials are described for the photocatalytic, electrocatalytic, and photoelectrocatalytic production, physisorption- and chemisorption-based storage, and utilisation of hydrogen in fuel cells; moreover, chemical and ammonia syntheses and steelmaking have been comprehensively discussed. Detailed insights and relevant comparisons are provided to demonstrate the efficacies of the abovementioned materials in the hydrogen sector. This broad overview of materials development will promote the hydrogen economy and inspire researchers and policymakers to appreciate the roles of materials and invest more in their research and development.

Borocarbonitride (BCN) based materials are finding increasing attention for a range of applications owing to their outstanding features. BCN is generally realized through the coupling of carbon and boron nitride (BN) with the latter being analogous to graphene and recognized due to its good electrical/mechanical properties and thermal/chemical stability. Although BCN is widely acknowledged for tunable bandgap, one of its fascinating yet less explored aspects is porosity. The porous features including high surface area and pore size are always favorable factors to enhance the efficiency of non-porous materials. This review is focused on parallel coverage and comparison of BCN and BN in terms of their synthesis methods, structure-property relationships, and application perspectives. This review aims to provide the readers with up-to-date information on the aspects that have not been covered previously. The review also covers the detailed explanation and analysis of various factors affecting the structure and property relationship that could lead to the development of more advanced BCN nanoporous structures. In terms of the application perspectives, emerging fields such as energy storage and conversion and photocatalysis and conventional fields such as adsorption are covered and the review concludes by providing illustrations on current challenges and future directions.

Adding to the growing literature on circular economy (CE) and employing the theoretical lens of change management, this research explores SMEs¿ challenges in the emerging markets context of India for adopting CE practices. We use a multi-case qualitative design, interviewing senior leaders and owners of Indian SMEs, CE intermediaries and two large firms on the nature and extent of critical barriers and enablers of CE adoption. Including CE market intermediaries, sustainability and CE managers of large organizations, who are required to educate and incentivize CE adoption of their SME value chain members, we analyze the barriers and opportunities from both sides of the coin. We develop a multilevel theoretical framework grounded in CE and change management literature, which presents the nature and extent of CE activities, barriers and contextual enablers of SMEs¿ adoption of CE in emerging markets. Implications for policy, theory and practice are also discussed.

The layer-by-layer mesoporous nanohybrids of Ni-Cr-layered double hydroxide (Ni-Cr-LDH) and polyoxotungstate nanoclusters (Ni-Cr-LDH-POW) are prepared via exfoliation reassembling strategy. The intercalative hybridization of Ni-Cr-LDH with POW nanoclusters leads to forming a layer-by-layer stacking framework with significant expansion of the interplanar spacing and surface area. The aqueous hybrid supercapacitor (AHSC) and all-solid-state hybrid supercapacitor (SSHSC) devices are fabricated using Ni-Cr-LDH-POW nanohybrid as a cathode and reduced graphene oxide (rGO) as an anode material. Notably, the NCW-2//rGO AHSC device delivers an ED of 43 Wh kg-1 at PD of 1.33 kW kg-1 and excellent electrochemical stability over 10,000 charge¿discharge cycles. Moreover, NCW-2//rGO SSHSC exhibits an ED of 34 Wh kg-1 at PD of 1.32 kW kg-1 with capacitance retention of 86% after 10,000 cycles. These results highlight the excellent electrochemical functionality and advantages of the Ni-Cr-LDH-POW nanohybrids as a cathode for hybrid supercapacitors.

Engineered nanomaterials (ENMs) are at the forefront of many technological breakthroughs in science and engineering. The extensive use of ENMs in several consumer products has resulted in their release to the aquatic environment. ENMs entering the aquatic ecosystem undergo a dynamic transformation as they interact with organic and inorganic constituents present in aquatic environment, specifically abiotic factors such as NOM and clay minerals, and attain an environmental identity. Thus, a greater understanding of ENM-abiotic factors interactions is required for an improved risk assessment and sustainable management of ENMs contamination in the aquatic environment. This review integrates fundamental aspects of ENMs transformation in aquatic environment as impacted by abiotic factors, and delineates the recent advances in bioavailability and ecotoxicity of ENMs in relation to risk assessment for ENMs-contaminated aquatic ecosystem. It specifically discusses the mechanism of transformation of different ENMs (metals, metal oxides and carbon based nanomaterials) following their interaction with the two most common abiotic factors NOM and clay minerals present within the aquatic ecosystem. The review critically discusses the impact of these mechanisms on the altered ecotoxicity of ENMs including the impact of such transformation at the genomic level. Finally, it identifies the gaps in our current understanding of the role of abiotic factors on the transformation of ENMs and paves the way for the future research areas.

In this paper, biocomposites were prepared with carrageenan/fish scale/allopurinol collagen by solution method. Carrageenan fish scale collagen and allopurinol were used at different ratio and the effect of varying the component ratio was investigated by studying the shape, morphology, thermal behavior, and drug release ability of the biocomposites. By varying the carrageenan/collagen ratio, the shape of the biocomposites can be modified. When high amount of carrageenan was used, biocomposites were obtained in film whereas higher content of collagen produced powder form of biocomposites. The characteristics of the biocomposites were studied by Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction Analysis (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Thermal Gravimetric Analysis (TGA), and Differential Scanning Calorimetric (DSC) techniques. The drug (allopurinol) release ability of the biocomposites was evaluated with Ultraviolet¿Visible Spectroscopy (UV¿Vis). Biocomposites in the powder form are different from the biocomposites in the film form by having different shape, morphology, thermal behavior, and drug release ability. However, both are sensitive to pH of solution in drug release process. In addition, the cell toxicity of allopurinol and these biocomposites was evaluated with Vero cells by MTT method. The obtained results confirmed that the biocomposite materials in film shape are promising for the application in biomedicine.

N-doped highly porous carbons (NHPCs) derived from Victorian brown coal (VBC) were prepared through direct KOH activation in the presence of urea as the N source. Different weight ratios of KOH (VBC-urea mixture: KOH=1:0, 1:1, 1:2, and 1:3) have been used to optimize the porosity of NHPCs. Benefiting from the synergistic effect of the high porosity and N doping, the synthesized material with a high specific surface area of 687 m2/g and the N content at ~11 at% exhibited a high specific discharge capacity of 604.6 mAh/g at a current density of 0.1 A/g after 100 cycles and a high-rate performance of 245 mAh/g at 3 A/g. The developed material delivered a reversible capacity of 707.7 mAh/g at 0.05 A/g at the end of rate performance. The long-term cycling test performed at 1 A/g illustrates a stable and reversible capacity of 268 mAh/g after 1000 cycles with a coulombic efficiency of 100% and charge retention of 88%. The hierarchically porous carbon matrix with N doping can increase the Li+ diffusion efficiency and accelerate the charge transfer, thus leading to enhanced high-rate performance, superior reversibility, and high cyclic stability.

Graphene, sp2-hybridized miracle material of 21st century possesses extra-ordinary physico-chemical properties and hence inspires several salient frontline applications. Lack of magnetic ordering limits its dream spintronic chips applications. Phosphorus and sulfur being large and electron-rich atoms, if adequately doped to graphene, will enable carrier injection (worth for electronic chips) and net spin-polarized electrons (worth for spintronic chips) in it. However, in-plane (preferentially) ultra-doping of graphene by phosphorus and sulfur is extremely challenging by conventional techniques. We report microwave doping of graphene by phosphorus and sulfur atoms up to record doping level of 15 and 12.5 % respectively which render graphene room temperature ferromagnetism with a saturation magnetization as high as 0.13 emu/g and 0.15 emu/g for phosphorus and sulfur doping ¿respectively¿. Spin-polarized DFT band structure calculations suggest vivid spin asymmetry caused by doping which supports our experimental findings of primarily graphitic doped samples. Microwave doping of graphene by phosphorus and sulfur brings in dramatic changes in its magnetic behaviour and thus the present research establishes it as a novel doping strategy with excellent efficiency, scalability, and reproducibility, and will inspire new generations of graphene-based spintronic chips.

Metal-semiconductor diodes constructed from two-dimensional (2D) van der Waals heterostructures show excellent gate electrostatics and a large built-in electric field at the tunnel junction, which can be exploited to make highly sensitive photodetector. Here we demonstrate a metal-semiconductor photodiode constructed by the monolayer graphene (Gr) on a few-layer black phosphorus (BP). Due to the presence of a built-in potential barrier (~0.09 ± 0.03 eV) at the Gr-BP interface, the photoresponsivity of the Gr-BP device is enhanced by a factor of 672%, and the external quantum efficiency (EQE) increases to 648% from 84% of the bare BP. Electrostatic gating allows the BP channel to be switched between p-type and n-type conduction. We further demonstrate that excitation laser power can be used to control the current polarity of the Gr-BP device due to photon-induced doping. The versatility of the Gr-BP junctions in terms of electrostatic bias-induced or light-induced switching of current polarity is potentially useful for making dynamically reconfigurable digital circuits.

With the threat of increasing SARS-CoV-2 cases looming in front of us and no effective and safest vaccine available to curb this pandemic disease due to its sprouting variants, many countries have undergone a lockdown 2.0 or planning a lockdown 3.0. This has upstretched an unprecedented demand to develop rapid, sensitive, and highly selective diagnostic devices that can quickly detect coronavirus (COVID-19). Traditional techniques like polymerase chain reaction have proven to be time-inefficient, expensive, labor intensive, and impracticable in remote settings. This shifts the attention to alternative biosensing devices that can be successfully used to sense the COVID-19 infection and curb the spread of coronavirus cases. Among these, nanomaterial-based biosensors hold immense potential for rapid coronavirus detection because of their noninvasive and susceptible, as well as selective properties that have the potential to give real-time results at an economical cost. These diagnostic devices can be used for mass COVID-19 detection to understand the rapid progression of the infection and give better-suited therapies. This review provides an overview of existing and potential nanomaterial-based biosensors that can be used for rapid SARS-CoV-2 diagnostics. Novel biosensors employing different detection mechanisms are also highlighted in different sections of this review. Practical tools and techniques required to develop such biosensors to make them reliable and portable have also been discussed in the article. Finally, the review is concluded by presenting the current challenges and future perspectives of nanomaterial-based biosensors in SARS-CoV-2 diagnostics.

We demonstrate a synthesis of copper nanoparticles decorated over nitrogen-doped mesoporous carbon with different N and Cu contents which exhibit conducting, redox, basic, adsorption, and excellent textural properties. These materials are prepared through a nanotemplating approach by simultaneously encapsulating sucrose, guanidine hydrochloride, and Cu(NO3)2 into the porous channels of mesoporous SBA-15 at a low carbonization temperature of 600 °C. The prepared materials exhibit an ordered mesoporous carbon framework with bimodal pores, decorated with nitrogen and Cu functionalities on the surface of the pores and in the wall structure. The presence of nitrogen functionalities in the porous carbon matrix not only helps to reduce the Cu ions but also stabilizes the nanoparticles and offers redox sites, which are beneficial for adsorption and electrochemical applications. The optimized sample exhibits the highest adsorption capacity of different gases such as CO2 ¿ 22.5 mmol/g at 273 K, H2 -13.5 mmol/g at 77 K at 30 bar and CH4 - 5 mmol/g at 298 K and 50 bar. We also demonstrate that the prepared material shows a high selectivity of adsorption towards CO2 in a mixture of CO2/H2 and CO2/CH4 and it also registers a high supercapacitance of 209 F g-1 at a current density of 1 A g-1 with excellent cyclic stability.

One of the key focuses of the agricultural industry for preventing the decline in crop yields due to pests is to develop effective, safe, green, and sustainable pesticide formulation. A key objective of industry is to deliver active ingredients (AIs) that have minimal off site migration and non-target activity. Nanoporous materials have received significant attention internationally for the efficient loading and controlled, targeted delivery of pesticides. This is largely made possible due to their textural features including high surface area, large pore-volume, and tunable pore size. Additionally, the easier manipulation of their surface chemistry and stability in different environments are added advantages. The unique features of these materials allow them to address the solubility of the active ingredients, their efficient loading onto the porous channels, and slow and controlled delivery over time. One of their major advantages is the wide range of materials that could be suitably designed via different approaches to either adsorb, encapsulate, or entrap the active ingredient. This review is a timely presentation of recent progress made in nanoporous materials and discusses critical aspects of pesticide formulation and delivery.

With the ever-increasing demand for lithium (Li) for portable energy storage devices, there is a global concern associated with environmental contamination of Li, via the production, use, and disposal of Li-containing products, including mobile phones and mood-stabilizing drugs. While geogenic Li is sparingly soluble, Li added to soil is one of the most mobile cations in soil, which can leach to groundwater and reach surface water through runoff. Lithium is readily taken up by plants and has relatively high plant accumulation coefficient, albeit the underlying mechanisms have not been well described. Therefore, soil contamination with Li could reach the food chain due to its mobility in surface- and ground-waters and uptake into plants. High environmental Li levels adversely affect the health of humans, animals, and plants. Lithium toxicity can be considerably managed through various remediation approaches such as immobilization using clay-like amendments and/or chelate-enhanced phytoremediation. This review integrates fundamental aspects of Li distribution and behaviour in terrestrial and aquatic environments in an effort to efficiently remediate Li-contaminated ecosystems. As research to date has not provided a clear picture of how the increased production and disposal of Li-based products adversely impact human and ecosystem health, there is an urgent need for further studies on this field.

In order to overcome the current energy and environment crisis caused by fossil fuels depletion and greenhouse gas emission, it is indispensable to introduce new, eco-friendly, high-performance materials into energy conversion and storage applications. 2D transition metal oxides (TMOs) are regarded as the promising candidates due to their excellent electrochemical properties. However, their innate poor electronic conductivity greatly restricts their applications in energy conversion and storage. This review discusses and summarizes the developed strategies to overcome the limitation through surface modification including defect engineering, heteroatom incorporation and interlayer doping, as well as hybridization with conductive materials. In addition, a detailed summary of their synthesis and applications in supercapacitors, lithium ion batteries and electrocatalysis is included. Finally, future prospective such as opportunities and challenges is discussed for the successful implementation of 2D TMOs in the field of energy applications.

The isopropylation of naphthalene (NP) was carried out over a BEA zeolite (BEA38; SiO2/Al2O3 = 38) focused on the selectivities for diisopropylnaphthalene (DIPN) and triisopropylnaphthalene (TriIPN) isomers. The isopropylation gave possible eight DIPN isomers including ß,ß- (2,6- and 2,7-), a,ß- (1,3-, 1,6-, and 1,7-), and a,a- (1,4- and 1,5-). The catalysis over BEA works two types of controls: kinetic control operates to form predominantly bulky and unstable a,a-DIPN at low temperatures, and thermodynamic controls work for the predominant formation of the slim and stable ß,ß-DIPN at high temperatures, although the intermediately bulky and stable a,ß-DIPN are the major products through both controls. The enhanced selectivities for ß,ß-DIPN were observed at the early stages of the catalysis in the range of 200-300 °C, which operate under new type of thermodynamic control over fresh catalyst through thermodynamically preferred transition states; however, they decreased with the increase in the selectivities for a,a- and a,ß-DIPN, and converged after prolonged reaction period. The isopropylation of DIPN isomers gives TriIPN isomers: unstable and bulky 1,3,5- and 1,4,6-TriIPN with a,a,ß-substitution, and stable and slim 1,3,7- and 1,3,6-TriIPN with a,ß,ß-substitution. The low temperatures favor the former isomers, whereas the selectivity for the latter isomers increases with increasing reaction temperature. These results indicate that TriIPN isomers principally form under kinetic control at low temperatures, and thermodynamic controls participate in the catalysis at high temperatures. The selectivities for TriIPN isomers kept constant during the reaction at all temperatures: 200, 250, and 300 °C. The catalysis occurs inside the BEA channels and allow even the formation of bulky 1,3,5- and 1,4,6-TriIPN; however, all isomers cannot be isomerized to the others in the channels and on the external surfaces. Severe coke-deposition occurred during the catalysis, particularly in the early stages; however, the catalyst is recovered by the calcination with a small change in catalytic activity.

The isopropylation of naphthalene (NP) over USY zeolite (FAU06, SiO2/Al2O3 = 6) gave all eight possible diisopropylnaphthalene (DIPN) isomers: ß,ß- (2,6- and 2,7-), a,ß- (1,3-, 1,6-, and 1,7-), and a,a- (1,4- and 1,5-). The catalyses were operated under kinetic and/or thermodynamic controls depending on the reaction temperatures since the cavities of FAU topology are wide enough to form all DIPN isomers. Enhanced selectivities for ß,ß-DIPN were observed at the early stages at 200°C, 250°C, and 300°C although the selectivities decreased with the increasing periods, accompanying the increase in a,a- and a,ß-DIPN. The enhancement occurred under new types of thermodynamic controls through thermodynamically preferred transition states to ß,ß-DIPN. Triisopropylnaphthalene (TriIPN) isomers were also formed in the isopropylation. Unstable a,a,ß-TriIPN (1,4,6- and 1,3,5-) was predominantly formed at lower temperatures, however, decreased with the increased of stable a,ß,ß-TriIPN (1,3,6- and 1,3,7-) at higher temperatures. The predominant formation of 1,4,6-TriIPN was also observed in the initial stages in the range of 200°C, 250°C, and 300°C, as reaction period was increased, while the selectivity for the isomer was decreased with concomitant increase in the selectivities for the other isomers. These changes of the selectivities operated under kinetic and/or thermodynamic controls. Large cavities of the zeolite allowed the formation of all TriIPN isomers without steric restriction.

We report on the preparation of ordered mesoporous carbon nitrides (MCN) with a 3D porous structure, tuneable nitrogen contents and basicity and their basic catalytic activities on the Knoevenagel condensation of benzaldehyde with malononitrile. The chemical structure and the nitrogen contents of the materials are finely tuned with the simple adjustment of the calcination temperature from 350 to 550 °C. The samples prepared at 350 and 400 °C exhibit C3N5 structures with 1-amino/imino-1,2,4-triazole moieties, whereas the samples synthesised at 450, 500, and 550 °C possess C3N4 structures with 2-amino/imino-1,3,5-triazine moieties. The materials prepared at the temperature lower than 400 °C show much higher activity than those of the samples prepared at 450, 500 and 550 °C. The change in the catalytic activities of these materials is linked with the change of the structure, nitrogen contents and the functional groups on the surface of the materials prepared at different temperatures. CO2 temperature programme desorption study reveals that 1-amino/imino-1,2,4-triazole moieties in C3N5 samples provide high basicity due to the strain in 5-membered 1,2,4-triazole rings; however, the samples with 1,3,5-triazine moieties have limited basicity which significantly affects the catalytic activity of the material. The optimised C3N5 catalyst shows an enhanced catalytic activity when compared to other mesoporous basic catalysts and C3N4. It is also found that the optimised catalysts are highly stable and can be recycled several times and no major change in the activity is observed.

The synthesis of highly active and reusable mesoporous siliceous phosphotungstic acid materials (mPTA-Si) which are prepared through a simple self-assembly between phosphotungstic acid (PTA), the polymeric surfactant, and the silica precursor assisted by KCl for cyclohexylation of phenol is reported. The surface area and the acidity of these materials are tuned with a simple adjustment of PTA in the silica framework. The prepared samples exhibit mesoporous structure with a high surface area, but the structure is collapsed when the loading of PTA is high. It is established that the Keggin structure of PTA is retained on the final mPTA-Si. mPTA-Si with different loadings of PTA are employed as the catalysts for the cyclohexylation of phenol under liquid phase conditions. Among the catalysts studied, 10.0-mPTA-8.3Si calcined at 350 °C is found to be highly active, selective, and recyclable and offers 100% conversion of phenol with the highest selectivity for p-cyclohexylphenol (96.8%).

Highly efficient, low-cost electrocatalysts having superior activity and stability are crucial for practical electrochemical water splitting, which involves hydrogen and oxygen evolution reactions (HER and OER). The sustainable production of hydrogen fuel from electrochemical water splitting requires the development of a highly efficient and stable electrocatalyst with low overpotential that drives electrochemical redox reactions. Electrochemical water splitting using highly active nickel-iron layered double hydroxide (NiFe LDH) catalyst having a very high turnover frequency and mass activity is considered as a potential contender in the area of electrocatalysis owing to the practical challenges including high efficiency and long durability at low overpotential, which shows great potential in future hydrogen economy. This review includes certain recommendations on enhancing the electrocatalytic performance of NiFe LDH-based electrocatalyst, particularly through morphology engineering, construction of hierarchical/core-shell nanostructures, and doping of heteroatoms through combined experimental assessment and theoretical investigations, which in turn improve the electrocatalytic performance. Finally, emphasis is made on the bifunctional activity of the NiFe LDH catalyst for overall water splitting. At the end, the conclusions and future outlook for the design of the NiFe LDH catalyst towards scale-up for their use as electrolyzer at the industrial level are also discussed.

Skin cancer has emerged as one of the leading types of cancers in the world, causing a high impact on the global burden of health and the economy. Basal cell and squamous cell carcinoma are the localized forms of skin cancer with a high prevalence and can be treated with a high success rate. However, melanoma, a rare type of skin cancer with a high mortality rate, can metastasize and invade other parts of the body. Various skin cancer treatment approaches have been developed and advanced from localized to systemic treatment over the years to improve the low success rate associated with skin cancer, especially metastatic melanoma. The systemic treatment of skin cancer is highly benefitted by drug delivery systems (DDS) designed to function with much higher specificity and lower side effects than the direct treatment with drugs. While many nanomaterials based DDS have been developed in the past few years to take advantage of the small size and high functionality of nanomaterials, silica-based nanomaterials have recently emerged as the flexible DDS with a high biocompatibility, good clearance, a high drug loading capacity, and versatility to attach several drugs and targeting agents to its surface. In this review, recent progress in the treatment of melanoma using silica-based nanomaterials and their hybrids is discussed, highlighting the versatility and potential of these emerging nanomaterials as the DDS for delivering various molecules, including drugs and immunotherapy agents, peptides, and radio- and photo-active agents. The review also introduces various therapies available for the treatment of melanoma, including surgery, chemotherapy, targeted therapy, phototherapy, and immunotherapy and discusses the improvement in these therapies based on silica-based DDS. The review also highlights the role of silica nanomaterials and their hybrids in delivering combination therapy and the advantages of silica nanohybrids over pure silica-based DDS. Finally, we summarize the present status of silica-based nanomaterials in melanoma treatment and the current challenges that have to be solved for the clinical translation of these materials as DDS.

Air pollution is a global challenge and researchers have been making tremendous efforts towards its abatement using existing or novel materials. To date, various porous solid adsorbent materials have gained significant attention, due to their textural properties, ease of modification, efficiency, selectivity, and recyclability. Although carbon-based adsorbents show promising adsorption efficiency, the capacity of the materials can be further enhanced and made more specific by various surface treatment methods. Functionalization with acidic/basic functionalities or incorporation of metal/metal oxides enhances the pollutant removal capacity of the granular activated carbon (GAC)/activated carbon fiber cloth (ACFC). Similarly, different modifications are performed on carbon aerogels with a view to make it appropriate for specific applications such as removal of CO2, CO, and volatile organic compounds. Currently, carbon aerogel nanohybrids from organic biomass are being developed through hydrothermal carbonization, which involves a cost-effective and green synthesis approach with chemical-free procedures compared to the hydrocarbon precursors. In silica-based adsorbents, attention has been given on engineering the pore size and nitrogen-occupied sites in order to tailor the surface functionalities which are crucial for understanding the interactions between pollutants and meso/microporous silica materials. In zeolites, the research is based on the effect of exchangeable cations and Si/Al ratio towards improving the surface chemistry between pollutants and adsorbents. The present review focuses on the development of these sorbents with an emphasis on environmental applications. The discussion shall revolve primarily towards the synthesis and surface modification of adsorbents as well as the sorbent-adsorbate mechanism and its chemistry.

The term ¿Total petroleum hydrocarbons¿ (TPH) is used to describe a complex mixture of petroleum-based hydrocarbons primarily derived from crude oil. Those compounds are considered as persistent organic pollutants in the terrestrial environment. A wide array of organic amendments is increasingly used for the remediation of TPH-contaminated soils. Organic amendments not only supply a source of carbon and nutrients but also add exogenous beneficial microorganisms to enhance the TPH degradation rate, thereby improving the soil health. Two fundamental approaches can be contemplated within the context of remediation of TPH-contaminated soils using organic amendments: (i) enhanced TPH sorption to the exogenous organic matter (immobilization) as it reduces the bioavailability of the contaminants, and (ii) increasing the solubility of the contaminants by supplying desorbing agents (mobilization) for enhancing the subsequent biodegradation. Net immobilization and mobilization of TPH have both been observed following the application of organic amendments to contaminated soils. This review examines the mechanisms for the enhanced remediation of TPH-contaminated soils by organic amendments and discusses the influencing factors in relation to sequestration, bioavailability, and subsequent biodegradation of TPH in soils. The uncertainty of mechanisms for various organic amendments in TPH remediation processes remains a critical area of future research.

Aqueous film-forming foam, used in firefighting, and biowastes, including biosolids, animal and poultry manures, and composts, provide a major source of poly- and perfluoroalkyl substances (PFAS) input to soil. Large amounts of biowastes are added to soil as a source of nutrients and carbon. They also are added as soil amendments to improve soil health and crop productivity. Plant uptake of PFAS through soil application of biowastes is a pathway for animal and human exposure to PFAS. The complexity of PFAS mixtures, and their chemical and thermal stability, make remediation of PFAS in both solid and aqueous matrices challenging. Remediation of PFAS in biowastes, as well as soils treated with these biowastes, can be achieved through preventing and decreasing the concentration of PFAS in biowaste sources (i.e., prevention through source control), mobilization of PFAS in contaminated soil and subsequent removal through leaching (i.e., soil washing) and plant uptake (i.e., phytoremediation), sorption of PFAS, thereby decreasing their mobility and bioavailability (i.e., immobilization), and complete removal through thermal and chemical oxidation (i.e., destruction). In this review, the distribution, bioavailability, and remediation of PFAS in soil receiving solid biowastes, which include biosolids, composts, and manure, are presented.

Current and potential beneficial applications of engineered nanomaterials (ENM) are outweighed by the potential concern of their environmental implications. Understanding the impact of ENM release in the aquatic systems is complicated by the transport of the nanoparticles (NPs) especially in presence of various biotic and abiotic factors. Several attempts have been made to understand the aggregation and sedimentation of ENM in presence of individual factors such as natural organic matter and clay and in presence of salts to address their transportation and fate. The objective of the current study is to compare the effect of abiotic factors on the pH dependent stability and aggregation of TiO2 and CuO NP in a relevant fish embryo (E3) medium as a function of time. The aggregation and the sedimentation are compared in presence of humic acid (HA) alone, montmorillonite clay alone, and their combination. It is observed that in presence of HA, the aggregation of TiO2 NP and CuO NP decreases at pH 6, 8, and 10 and heteroagglomeration of TiO2 NP and CuO NP occurs with clay minerals at pH 2 and 4. It is also found that CuO NP are more stable than TiO2 NP in E3 medium and are perturbed to a lesser extent by the abiotic factors as compared to TiO2. Clay and HA are interesting naturally occurring matter in the aqueous environment that can affect the size, charge, and sedimentation behavior of ENM and thus affect their bioavailability and eventual toxicological fate.

Solution-based amine absorption technologies have been widely applied for CO2 capture, but they have several drawbacks. This paper reports on the synthesis of the first solid-state amine adsorbent prepared through a simple plasma polymerization and deposition on¿physicochemically modified natural mordenite¿clinoptilolite zeolite. The plasma deposition of amine polymer under certain conditions resulted in a significant increase in surface area-weighted CO2 adsorption capacity as the natural zeolite. The strength of the interaction between CO2 and the adsorbent was weaker for the plasma polymer-modified zeolite than without the plasma coating, which may facilitate regeneration. Both indications make the amine plasma polymer-based zeolite adsorbent a good candidate for CO2 adsorption and separation.

Heteroatom doped nanomaterials are reported to be excellent electrodes for energy storage and conversion applications. However, the introduction of these heteroatoms in materials such as carbon nitride is quite challenging owing to the poor thermodynamic stability of these atoms in the carbon matrix. In this report, we demonstrate the single-step approach for the preparation of highly ordered nanoporous carbon oxynitride (O-MCN) materials with tailored pore sizes by employing carbohydrazide as a single C, N, O precursor using nano-templating approach. Experimental characterization of the O-MCN confirms oxygen doping in C-N framework. Density functional theory (DFT) calculations demonstrate that the O-MCN optimized with AB type bilayer structure can adsorb nine Li ions per unit cell with mild Li-ion binding energy value of 5.16 eV. The synthesized O-MCN materials are firstly applied in Li-ion batteries as anode materials. The optimized O-MCN displays 2.5 times higher reversible capacity than that of non-porous g-C3N4 with remarkable stability in the long run in the Li-ion battery.

Catalyst synthesis is an art where an inefficient material can be remarkably converted into a highly active and selective catalyst by adopting a suitable synthetic strategy to tune its properties during synthesis. The underlying principle of the strategy presented here is the integration of tailoring the structural and chemical behavior of tin phosphates with tuned catalytic active centers directed by employing different structure directing agents (SDAs) and the attempt to understand this in detail. It is demonstrated how soft templates can be effectively used for their so far unknown utilization of tuning the active sites in phosphate containing catalysts. We found that, by using an appropriate synthesis strategy, it is possible to tune and control explicitly both the catalyst morphology and the nature of active sites at the same time. The 31P MAS NMR study revealed that employing SDAs in the synthesis strongly influenced the nature and amount of phosphate species in addition to porosity. The resultant different nanostructured SnPO catalysts were investigated for one-pot synthesis of alkyl levulinates via alcoholysis of furfuryl alcohol. Among the catalysts, SnPO-P123 exhibited greater butyl levulinate yield via alcoholysis of furfuryl alcohol with n-butanol and the study was extended to synthesize different alkyl levulinates. Importantly, the active sites in the SnPO-P123 catalyst responsible for the reaction were elucidated by a study using 2,6-lutidine as a basic probe molecule. This study therefore provides an avenue for rational design and construction of highly efficient and robust nanostructured SnPO catalysts to produce alkyl levulinates selectively. This journal is

Significant progress has been made on metal¿organic frameworks (MOFs), especially those with functional groups like amines or carboxylic acid groups. MOFs with uncoordinated nitrogen (UCN-MOFs) are attractive for many applications (owing to Lewis basicity and possible coordination) and for possible further modifications to have other functionalities. In this review, recent progress on the preparation, modification for other functionalities, and applications (mainly in adsorption) of UCN-MOFs with or without modification will be discussed. The prospects in the relevant fields are suggested.

Slags are a co-product produced by the steel manufacturing industry and have mainly been utilised for aggregates in concreting and road construction. The increased utilisation of slag can increase economic growth and sustainability for future generations by creating a closed-loop system, circular economy within the metallurgical industries. Slags can be used as a soil amendment, and slag characteristics may reduce leachate potential of heavy metals, reduce greenhouse gas emissions, as well as contain essential nutrients required for agricultural use and environmental remediation. This review aims to examine various slag generation processes in steel plants, their physicochemical characteristics in relation to beneficial utilisation as a soil amendment, and environmental implications and risk assessment of their utilisation in agricultural soils. In relation to enhancing recycling of these resources, current and emerging techniques to separate iron and phosphorus slag compositions are also outlined in this review. Although there are no known immediate direct threats posed by slag on human health, the associated risks include potential heavy metal contamination, leachate contamination, and bioaccumulation of heavy metals in plants, thereby reaching the food chain. Further research in this area is required to assess the long-term effects of slag in agricultural soils on animal and human health.

In this investigation, a hybrid of metal sulfide and carbon nitride (CN) is synthesized by in-situ chemical conversion between metallic species and a single precursor of carbon, nitrogen and sulfur elements through a strong p-d conjugation approach. It is observed that the local chemical alteration in the vicinity of N atom in the CN template triggers the formation of a highly p-conjugated CN system and efficient p-d hybridization at heterointerface. This is accelerated by partial substitution of the Fe atom for Mn ions in the MnS phase which significantly enhances the battery performance, delivering 2031 mA h g-1 after 500 cycles with inverse capacity growth. Via systematic in-depth characterizations, it is found that the gradual increase of Li-ion diffusion coefficients and charge transfer kinetics for repeated cycling is ascribed to the highly dispersed and uniform particles that are confined within the CN template through a strong p-d hybridization.

Valorisation of food waste offers an economical and environmental opportunity, which can reduce the problems of its conventional disposal. Food waste is commonly disposed of in landfills or incinerated, causing many environmental, social, and economic issues. Large amounts of food waste are produced in the food supply chain of agriculture: production, post-harvest, distribution (transport), processing, and consumption. Food waste can be valorised into a range of products, including biofertilisers, bioplastics, biofuels, chemicals, and nutraceuticals. Conversion of food waste into these products can reduce the demand of fossil-derived products, which have historically contributed to large amounts of pollution. The variety of food chain suppliers offers a wide range of feedstocks that can be physically, chemically, or biologically altered to form an array of biofertilisers and soil amendments. Composting and anaerobic digestion are the main large-scale conversion methods used today to valorise food waste products to biofertilisers and soil amendments. However, emerging conversion methods such as dehydration, biochar production, and chemical hydrolysis have promising characteristics, which can be utilised in agriculture as well as for soil remediation. Valorising food waste into biofertilisers and soil amendments has great potential to combat land degradation in agricultural areas. Biofertilisers are rich in nutrients that can reduce the dependability of using conventional mineral fertilisers. Food waste products, unlike mineral fertilisers, can also be used as soil amendments to improve productivity. These characteristics of food wastes assist in the remediation of contaminated soils. This paper reviews the volume of food waste within the food chain and types of food waste feedstocks that can be valorised into various products, including the conversion methods. Unintended consequences of the utilisation of food waste as biofertilisers and soil-amendment products resulting from their relatively low concentrations of trace element nutrients and presence of potentially toxic elements are also evaluated.

Prostate cancer (PCa) is one of the most commonly diagnosed cancers and is the fifth common cause of cancer-related mortality in men. Current methods for PCa treatment are insufficient owing to the challenges related to the non-specificity, instability and side effects caused by the drugs and therapy agents. These drawbacks can be mitigated by the design of a suitable drug delivery system that can ensure targeted delivery and minimise side effects. Silica based nanoparticles (SBNPs) have emerged as one of the most versatile materials for drug delivery due to their tunable porosities, high surface area and tremendous capacity to load various sizes and chemistry of drugs. This review gives a brief overview of the diagnosis and current treatment strategies for PCa outlining their existing challenges. It critically analyzes the design, development and application of pure, modified and hybrid SBNPs based drug delivery systems in the treatment of PCa, their advantages and limitations.

Polycyclic aromatic hydrocarbons (PAHs) are generated due to incomplete burning of organic substances. Use of fossil fuels is the primary anthropogenic cause of PAHs emission in natural settings. Although several PAH compounds exist in the natural environmental setting, only 16 of these compounds are considered priority pollutants. PAHs imposes several health impacts on humans and other living organisms due to their carcinogenic, mutagenic, or teratogenic properties. The specific characteristics of PAHs, such as their high hydrophobicity and low water solubility, influence their active adsorption onto soils and sediments, affecting their bioavailability and subsequent degradation. Therefore, this review first discusses various sources of PAHs, including source identification techniques, bioavailability, and interactions of PAHs with soils and sediments. Then this review addresses the remediation technologies adopted so far of PAHs in soils and sediments using immobilization techniques (capping, stabilization, dredging, and excavation), mobilization techniques (thermal desorption, washing, electrokinetics, and surfactant assisted), and biological degradation techniques. The pros and cons of each technology are discussed. A detailed systematic compilation of eco-friendly approaches used to degrade PAHs, such as phytoremediation, microbial remediation, and emerging hybrid or integrated technologies are reviewed along with case studies and provided prospects for future research.

Research on cerium oxide nanoparticles (nanoceria) has captivated the scientific community due to their unique physical and chemical properties, such as redox activity and oxygen buffering capacity, which made them available for many technical applications, including biomedical applications. The redox mimetic antioxidant properties of nanoceria have been effective in the treatment of many diseases caused by reactive oxygen species (ROS) and reactive nitrogen species. The mechanism of ROS scavenging activity of nanoceria is still elusive, and its redox activity is controversial due to mixed reports in the literature showing pro-oxidant and antioxidant activity. In light of its current research interest, it is critical to understand the behavior of nanoceria in the biological environment and provide answers to some of the critical and open issues. This review critically analyzes the status of research on the application of nanoceria to treat diseases caused by ROS. It reviews the proposed mechanism of action and shows the effect of surface coatings on its redox activity. It also discusses some of the crucial issues in deciphering the mechanism and redox activity of nanoceria and suggests areas of future research.

The surging demand for energy and staggering pollutants in the environment have geared the scientific community to explore sustainable pathways that are economically feasible and environmentally compelling. In this context, harnessing solar energy using semiconductor materials to generate charge pairs to drive photoredox reactions has been envisioned as a futuristic approach. Numerous inorganic crystals with promising nanoregime properties investigated in the past decade have yet to demonstrate practical application due to limited photon absorption and sluggish charge separation kinetics. Two-dimensional semiconductors with tunable optical and electronic properties and quasi-resistance-free lateral charge transfer mechanisms have shown great promise in photocatalysis. Polymeric graphitic carbon nitride (g-C3N4) is among the most promising candidates due to fine-tuned band edges and the feasibility of optimizing the optical properties via materials genomics. Constructing a two-dimensional (2D)/2D van der Waals (vdW) heterojunction by allies of 2D carbon nitride sheets and other 2D semiconductors has demonstrated enhanced charge separation with improved visible photon absorption, and the performance is not restricted by the lattice matching of constituting materials. With the advent of new 2D semiconductors over the recent past, the 2D/2D heterojunction assemblies are gaining momentum to design high performance photocatalysts for numerous applications. This review aims to highlight recent advancements and key understanding in carbon nitride based 2D/2D heterojunctions and their applications in photocatalysis, including small molecules activation, conversion, and degradations. We conclude with a forward-looking perspective discussing the key challenges and opportunity areas for future research.

Sp3 and sp2 hybridised carbon materials have been exploited for myriad applications owing to their unique electronic features. Novel carbon materials and its composites are synthesised by researchers with improved physico-chemical properties for various applications. These novel materials need to be characterised to decipher the structures. Vibrational spectroscopic studies have been used to understand the lattice dynamics of such carbon materials for the last six decades. Raman spectroscopy in particular has been a unique technique in such investigations as it provides bond-specific information at a molecular level which is desirable in understanding the microstructure of carbon. In this review, we highlight the potential of Raman spectroscopy to study the microstructure of different carbon allotropes such as graphene, carbon nanotubes, fullerene, and carbon nitride and its composites. In addition, perovskites has been receiving a lot of attention recently as the scientific community has realised their potential in the areas of material science and energy storage and conversion. This review also covers a few aspects of Raman spectroscopic studies of oxide and halide perovskites.