Nano-biogenic heavy metals adsorptive remediation for enhanced soil health and sustainable agricultural production.

Hazardous heavy metal (HM) pollution constitutes a pervasive global challenge, posing substantial risks to ecosystems and human health. The exigency for expeditious detection, meticulous monitoring, and efficacious remediation of HM within ecosystems is indisputable. Soil contamination, stemming from a myriad of anthropogenic activities, emerges as a principal conduit for HM ingress into the food chain. Traditional soil remediation modalities for HM elimination, while effective are labor-intensive, susceptible to secondary contamination, and exhibit limited efficacy in regions characterized by low metal toxicity. In response to these exigencies, the eco-friendly paradigm of bioremediation has garnered prominence as a financially judicious and sustainable remedial strategy. This approach entails the utilization of hyperaccumulators, Genetically Modified Microorganisms (GMM), and advantageous microbes. The current review offers a comprehensive elucidation of cutting-edge phyto/microbe-based bioremediation techniques, with a specific emphasis on their amalgamation with nanotechnology. Accentuating their pivotal role in advancing sustainable agricultural practices, the review meticulously dissects the synergistic interplay between plants and microbes, underscoring their adeptness in HM remediation sans secondary contamination. Moreover, the review scrutinizes the challenges intrinsic to implementing bioremediation-nanotechnology interface techniques and propounds innovative resolutions. These discernments proffer auspicious trajectories for the future of agriculture. Through the environmentally conscientious marvels of phyto/microbe bioremediation, an optimistic outlook emerges for environmental preservation and the cultivation of a sustainable, salubrious planet via the conduit of cleaner agricultural production.

Fe-based MOFs as promising adsorbents and photocatalysts for re-use water contained arsenic: Strategies and challenges.

Arsenic (As) contaminated water, especially groundwater reservoirs, is a major issue worldwide owing to its hazardous consequences on human health and the global environment issues. Also, irrigating agricultural fields with As-contaminated water not only produces an accumulation of As in the soil but also compromises food safety due to As entering into agricultural products. Hence, there is an urgent need to develop an efficient method for As removal in water. Fe-based MOFs have attained special attention due to their low toxicity, high water stability, better physical and chemical properties, and high abundance of iron. The arsenic species removal by Fe-MOF follows the adsorption and oxidation mechanism where As (III) converts into As (V). Moreover, the adsorption mechanism is facilitated by electrostatic interactions, H-bonding, acid-base interaction, hydrophobic interactions, van der Waals forces, π-π stacking interactions, and coordinative bindings responsible for Fe-O-As bond generation. This review thoroughly recapitulates and analyses recent advancements in the facile synthesis and potential application of Fe-based MOF adsorbents for the elimination of As ions. The most commonly employed hydro/solvothermal, ultrasonic, microwave-assisted, mechanochemical, and electrochemical synthesis for Fe-MOF has been discussed along with their adsorptive and oxidative mechanisms involved in arsenic removal. The effects of factors like pH and coexisting ions have also been discussed. Lastly, the article also proposed the prospects for developing the application of Fe-based MOF in treating As-contaminated water.

Sustainability, performance, and production perspectives of waste-derived functional carbon nanomaterials towards a sustainable environment: A review.

The survival of humanity is severely threatened by the massive accumulation of waste in the ecosystem. One plausible solution for the management and upcycling of waste is conversing waste at the molecular level and deriving carbon-based nanomaterial. The field of carbon nanomaterials with distinctive properties, such as exceptionally large surface areas, good thermal and chemical stability, and improved propagation of charge carriers, remains a significant area of research. The study demonstrates recent developments in high-value carbon-based photocatalysts synthesis from various waste precursors, including zoonotic, phytogenic, polyolefinic, electronic, and biomedical, highlighting the progression as photocatalysts and adsorbents for wastewater treatment and water splitting applications. This review highpoints the benefits of using waste as a precursor to support sustainability and circular economy and the risks associated with their use. Finally, we support that a sustainable society will eventually be realized by exploring present obstacles and potential steps for creating superior carbon-based nanomaterials in the future.

DFT and experimental studies of the facet-dependent oxygen vacancies modulated WS2/BiOCl-OV S-scheme structure for enhanced photocatalytic removal of ciprofloxacin from wastewater.

The present study explores visible light-assisted photodegradation of ciprofloxacin hydrochloride (CIP) antibiotic as a promising solution to water pollution. The focus is on transforming the optical and electronic properties of BiOCl through the generation of oxygen vacancies (OVs) and the exposure of (110) facets, forming a robust S-scheme heterojunction with WS2. The resultant OVs mediated composite with an optimal ratio of WS2 and BiOCl-OV (4-WS2/BiOCl-OV) demonstrated remarkable efficiency (94.3%) in the visible light-assisted photodegradation of CIP antibiotic within 1.5 h. The CIP degradation using 4-WS2/BiOCl-OV followed pseudo-first-order kinetics with the rate constant of 0.023 min-1, outperforming bare WS2, BiOCl, and BiOCl-OV by 8, 6, and 4 times, respectively. Density functional theory (DFT) analysis aligned well with experimental results, providing insights into the structural arrangement and bandgap analysis of the photocatalysts. Liquid chromatography-mass spectrometry (LC-MS) analysis utilized for identifying potentially degraded products while scavenging experiments and electron paramagnetic resonance (EPR) spin trapping analysis elucidated the S-scheme charge transfer mechanism. This research contributes to advancing the design of oxygen vacancy-mediated S-scheme systems in the realm of photocatalysis, with potential implications for addressing water pollution concerns.

"Long COVID" and Its Impact on The Environment: Emerging Concerns and Perspectives.

The COVID-19 pandemic has caused unprecedented global health and economic crises. The emergence of long COVID-19 has raised concerns about the interplay between SARS-CoV-2 infections, climate change, and the environment. In this context, a concise analysis of the potential long-term effects of the COVID-19 epidemic along with the awareness aboutenvironmental issues are realized. While COVID-19 effects in the short-term have reduced environmental air pollutants and pressures, CO2 emissions are projected to increase as the economy recovers and growth rates return to pre-COVID-19 levels. This review discusses the systematic effects of both the short-term and long-term effects of the pandemic on the clean energy revolution and environmental issues. This article also discusses opportunities to achieve long-term environmental benefits and emphasizes the importance of future policies in promoting global environmental sustainability. Future directions for growth and recovery are presented to cope with long COVID-19 epidemic along with the critical findings focussing on various aspects: waste management, air quality improvement.

Advances and perspectives of nanomaterials for photocatalytic degradation of biological ethylene toward the postharvest improvement of agricultural products.

To date, intensive emphasis is required to develop advanced postharvest technologies to ensure food security, increase nutrition, and improve farmers toward cleaner production. How to effectively degrade the harmful gaseous ethylene (C2H4) biosynthesis, which distributes heavy losses of fresh-cut fruits and vegetables, has received considerable attention. Among various advanced techniques, photocatalytic degradation of biological C2H4 is proposed as the most promising method to solve this issue. In this context, the recent studies on the photodegradation of C2H4 have been critically summarized and highlighted. Many photocatalysts, including TiO2-based and non-TiO2-based (metal oxides (ZnO, WO3, Ga2O3), molybdates (ß-Ag2MoO4), phosphides (Ag3PO4), perovskite oxides (Bi2WO6)) nanomaterials, have been revealed with credible performance results. Also, varying reaction parameters to optimize the photocatalytic degradation efficacy in the literature are summarized. We also discussed the current status, challenges, and prospects for enhanced photodegradation of C2H4 in this study. The efficacy and economics of photodegradation have played an essential role in selecting a particular type of photocatalyst. Although many efforts have been made, significant improvements are still required for photocatalysis. In this work, we have also successfully suggested some strategies to further promote this concept for controlling and degrading plant-generated C2H4 in fruit and vegetable postharvest in a sustainable and economically feasible manner.

Emergence of CuInS2 derived photocatalyst for environmental remediation and energy conversion.

Hydrogen production, catalytic organic synthesis, carbon dioxide reduction, environmental purification, and other major fields have all adopted photocatalytic technologies due to their eco-friendliness, ease of use, and reliance on sunlight as the driving force. Photocatalyst is the key component of photocatalytic technology. Thus, it is of utmost importance to produce highly efficient, stable, visible-light-responsive photocatalysts. CIS stands out among other visible-light-response photocatalysts for its advantageous combination of easy synthesis, non-toxicity, high stability, and suitable band structure. In this study, we took a brief glance at the synthesis techniques for CIS after providing a quick introduction to the fundamental semiconductor features, including the crystal and band structures of CIS. Then, we discussed the ways doping, heterojunction creation, p-n heterojunction, type-II heterojunction, and Z-scheme may be used to modify CIS's performance. Subsequently, the applications of CIS towards pollutant degradation, CO2 reduction, water splitting, and other toxic pollutants remediation are reviewed in detail. Finally, several remaining problems with CIS-based photocatalysts are highlighted, along with future potential for constructing more superior photocatalysts.

Covalent organic frameworks (COFs) core@shell nanohybrids: Novel nanomaterial support towards environmental sustainability applications.

Covalent organic frameworks (COFs) based on core@shell nanohybrids have recently received significant attention and have become one of the most promising strategies for improving the stability and catalytic activity of COFs. Compared with traditional core@shell, COF-based core@shell hybrids own remarkable advantages, including size-selective reactions, bifunctional catalysis, and integration of multiple functions. These properties could enhance the stability and recyclability, resistance to sintering, and maximize the electronic interaction between the core and the shell. The activity and selectivity of COF-based core@shell could be simultaneously improved by taking benefit of the existing synergy between the functional encapsulating shell and the covered core material. Considering that, we have highlighted various topological diagrams and the role of COFs in COF-based core@shell hybrid for activity and selectivity enhancement. This concept article provides all-inclusive advances in the design and catalytic applications of COF-based core@shell hybrids. Various synthetic techniques have been developed for the facile tailoring of functional core@shell hybrids, including novel seed growth, in-situ, layer-by-layer, and one-pot method. Importantly, charge dynamics and structure-performance relationships are investigated through different characterization techniques. Different COF-based core@shell hybrids with established synergistic interactions have been detailed, and their influence on stability and catalytic efficiency for various applications is explained and discussed in this contribution. A comprehensive discussion on the remaining challenges associated with COF-based core@shell nanoparticles and research directions has also been provided to deliver insightful ideas for additional future developments.

Integrating K and P co-doped g-C3N4 with ZnFe2O4 and graphene oxide for S-scheme-based enhanced adsorption coupled photocatalytic real wastewater treatment.

Recently, there has been a significant increase in the interest of using photocatalysis for environmental clean-up applications. In this research, potassium, and phosphorus co-doped graphitic carbon nitride (KPCN) photocatalyst modified with graphene oxide (GO) and heterostructured with ZnFe2O4 was synthesized via the hydrothermal method (KPCN/GO/ZnFe2O4). The photoactivity of KPCN/GO/ZnFe2O4 photocatalyst was examined for the photocatalytic degradation of target pollutants such as methylene blue (MB) dye, rhodamine B (RhB) dye, and tetracycline (TC) antibiotic. Furthermore, the chemical oxygen demand (COD) removal efficiency for real wastewater was determined to explore the practical application of KPCN/GO/ZnFe2O4 photocatalyst. The degradation efficiencies of bare graphitic carbon nitride, KPCN, KPCN/GO, and KPCN/GO/ZnFe2O4 photocatalysts for tetracycline antibiotics were 30%, 42%, 57%, and 87% within 60 min, respectively. Moreover, KPCN/GO/ZnFe2O4 photocatalyst showed 71% COD removal efficiency within 240 min. The •OH and •O2- were the major reactive species in the photocatalytic process. Results showed that the degradation efficiencies of graphitic carbon nitride were greatly enhanced upon doping and further improved with the addition of GO and ZnFe2O4. Doping improved light harvesting, GO enhanced the adsorption ability and heterojunction with ZnFe2O4 enhanced the charge separation as well as the reusability of synthesized KPCN/GO/ZnFe2O4 photocatalyst.

Panorama of biogenic nano-fertilizers: A road to sustainable agriculture.

The ever-increasing demand for food from the growing population has augmented the consumption of fertilizers in global agricultural practices. However, the excessive usage of chemical fertilizers with poor efficacy is drastically deteriorating ecosystem health through the degradation of soil fertility by diminishing soil microflora, environment contamination, and human health by inducing chemical remnants to the food chain. These challenges have been addressed by the integration of nanotechnological and biotechnological approaches resulting in nano-enabled biogenic fertilizers (NBF), which have revolutionized agriculture sector and food production. This review critically details the state-of-the-art NBF production, types, and mechanism involved in cultivating crop productivity/quality with insights into genetic, physiological, morphological, microbiological, and physiochemical attributes. Besides, it explores the associated challenges and future routes to promote the adoption of NBF for intelligent and sustainable agriculture. Furthermore, diverse applications of nanotechnology in precision agriculture including plant biosensors and its impact on agribusiness and environmental management are discussed.

An overview on ZnO-based sonophotocatalytic mitigation of aqueous phase pollutants.

Over the past several decades, the increase in industrialization provoked the discharge of harmful pollutants into the environment, affecting human beings and ecosystems. ZnO-based photocatalysts seem to be the most promising photocatalysts for treating harmful pollutants. However, fast charge carrier recombination, photo corrosion, and long reaction time are the significant factors that reduce the photoactivity of ZnO-based photocatalysts. In order to enhance the photoactivity of such photocatalysts, a combined process i.e., sonocatalysis + photocatalysis = sonophotocatalysis was used. Sonophotocatalysis is one of several different AOP methods that have recently drawn considerable interest, as it produces high reactive oxygen species (ROS) which helps in the oxidation of pollutants by acoustic cavitation. This combined technique enhanced the overall efficiency of the individual method by overcoming its limiting factors. The current review aims to present the theoretical and fundamental aspects of sonocatalysis and photocatalysis along with a detailed discussion on the benefits that can be obtained by the combined process i.e., US + UV (sonophotocatalysis). Also, we have provided a comparison of the excellent performance of ZnO to that of the other metal oxides. The purpose of this study is to discuss the literature concerning the potential applications of ZnO-based sonophotocatalysts for the degradation of pollutants i.e., dyes, antibiotics, pesticides, phenols, etc. That are carried out for future developments. The role of the produced ROS under light and ultrasound stimulation and the degradation mechanisms that are based on published literature are also discussed. In the end, future perspectives are suggested, that are helpful in the development of the sonophotocatalysis process for the remediation of wastewater containing various pollutants.

Potential of novel dual Z-scheme carbon quantum dots decorated MnIn2S4/CdS/Bi2S3 heterojunction for environmental applications.

In this work, CQDs decorated MnIn2S4/CdS/Bi2S3 heterojunction was prepared successfully by hydrothermal technique for photocatalytic disinfection of Escherichia coli (E. coli) and mineralization of methyl orange (MO) dye. The charge transferal route and mineralization process in CQDs-MnIn2S4/CdS/Bi2S3 heterojunction were comprehensively investigated by advanced spectroscopic techniques. The improved visible-light activity and enhanced photo-generated charge transferal efficacy caused dual Z-scheme CQDs-MnIn2S4/CdS/Bi2S3 heterojunction to achieve boosted photodegradation ability. The catalytic degradation trend was followed as CQDs-MnIn2S4/CdS/Bi2S3 > MnIn2S4 > CdS > Bi2S3. The dye was mineralized within 180 min under visible light irradiation. The effect of reaction parameters, pH effect, catalyst dosage, and H2O2 addition on MO degradation was also investigated. The degradation rate was maximal at pH 4 with a pseudo-first-order rate constant, 0.0438 min-1. The assessment of antibacterial properties revealed that CQDs-MnIn2S4/CdS/Bi2S3 composite effectively inactivated E. coli under visible light. Scavenging experiments, transient photocurrent response, and electron spin resonance spectroscopy suggested that •[Formula: see text] and holes were the dominant reactive species. The Z-scheme heterojunction is recyclable up to ten photocatalytic cycles according to recycling experiments. This research indicates the importance of dual Z-scheme CQDs decorated MnIn2S4/CdS/Bi2S3 heterojunction in wastewater remediation.

Natural Products as Potential Therapeutic Agents for SARS-CoV-2: A Medicinal Chemistry Perspective.

Coronavirus is a single-stranded RNA virus discovered by virologist David Tyrrell in 1960. Till now seven human corona viruses have been identified including HCoV-229E, HCoVOC43, HCoV-NL63, HCoV-HKU1, SARS-CoV, MERS-CoV and SARS-CoV-2. In the present scenario, the SARS-CoV-2 outbreak causing SARS-CoV-2 pandemic, became the most serious public health emergency of the century worldwide. Natural products have long history and advantages for the drug discovery process. Almost 80% of drugs present in market are evolved from the natural resources. With the outbreak of SARS-CoV-2 pandemic, natural product chemists have made significant efforts for the identification of natural molecules which can be effective against the SARSCoV- 2. In current compilation we have discussed in vitro and in vivo anti-viral potential of natural product-based leads for the treatment of SARS-CoV-2. We have classified these leads in different classes of natural products such as alkaloids, terpenoids, flavonoids, polyphenols, quinones, cannabinoids, steroids, glucosinolates, diarylheptanoids, etc. and discussed the efficacy and mode of action of these natural molecules. The present review will surely opens new direction in future for the development of promising drug candidates, particularly from the natural origin against coronaviruses and other viral diseases.

Polymer Membranes of Zeolitic Imidazole Framework-8 with Sodium Alginate Synthesized from ZIF-8 and Their Application in Light Gas Separation.

The potential of nanocomposite membranes (NCMs) prepared by the sodium alginate polymer and embedded with synthesized zeolitic imidazole framework-8 (ZIF-8) as fillers having microporous structure in the application of separation of gaseous mixture generated by the process of methane reforming was assessed. ZIF-8 crystals were created through hydrothermal synthesis, with sizes varying from 50 to 70 nm. NCMs were prepared with a 15% filler loading, i.e., synthesized ZIF-8. NCMs (ZIF-8) having H2 permeability of 28 Barrer and H2/CH4 selectivity of 125 outperformed neat polymer membranes in terms of separation performance at ambient temperature and 4 kg/cm2 pressure. The purity of H2 increased to as high as 95% among the measured values. The NCMs did not, however, outperform a neat polymer membrane in terms of their ability to separate mixtures of gases. Moreover, the combination of ZIF-8 as a filler with sodium alginate was new and had not been reported previously. As a result, it is worthwhile to investigate.

O and S co-doping induced N-vacancy in graphitic carbon nitride towards photocatalytic peroxymonosulfate activation for sulfamethoxazole degradation.

Doping-induced vacancy engineering of graphitic carbon nitride (GCN) is beneficial for bandgap modulation, efficient electronic excitation, and facilitated charge carrier migration. In this study, synthesis of oxygen and sulphur co-doped induced N vacancies (OSGCN) by the hydrothermal method was performed to activate peroxymonosulfate (PMS) for sulfamethoxazole (SMX) antibiotic degradation and H2 production. The results from experimental and DFT simulation studies validate the synergistic effects of co-dopants and N-vacancies, i.e., bandgap lowering, electron-hole pairs separation, and high solar energy utilization. The substitution of sp2 N atom by O and S co-dopants causes strong delocalization of HOMO-LUMO distribution, enhancing carrier mobility, increasing reactive sites, and facilitating charge-carrier separation. Remarkably, OSGCN/PMS photocatalytic system achieved 99.4% SMX degradation efficiency and a high H2 generation rate of 548.23 µ mol g-1 h-1 within 60 min and 36 h, respectively under visible light irradiations. The SMX degradation kinetics was pseudo-first-order with retained recycling efficiency up to 4 catalytic cycles. The results of EPR and chemical scavenging experiments revealed the redox action of reactive oxidative species, wherein 1O2 was the dominant reactive species in SMX degradation. The identification of formed intermediates and the SMX stepwise degradation pathway was investigated via LC-MS analysis and DFT studies, respectively. The results from this work anticipated deepening the understanding of PMS activation by substitutional co-doping favoring N-vacancy formation in GCN lattice for improved photocatalytic activity.

Constructing α-Fe2O3/g-C3N4/SiO2 S-scheme-based heterostructure for photo-Fenton like degradation of rhodamine B dye in aqueous solution.

This work successfully fabricated graphitic carbon nitride and magnetically recoverable α-Fe2O3/g-C3N4/SiO2 photo-Fenton catalysts using thermal polycondensation and in situ-simple precursor drying-calcination process, respectively, was examined for model synthetic rhodamine B (RhB) dye in the presence of H2O2 and acidic pH under simulated visible light irradiation. An aqueous suspension of the reaction mixture of dye-containing wastewater was fully degraded and reached 97% of photo-Fenton degradation efficiency within 120 min followed by the production of hydroxyl radical (•OH). The dominant hydroxyl radical position generated surface charge, electrostatic potential distribution, and average local ionization potential, which contributed to the complete mineralization of RhB dye, according to the density functional theory (DFT) calculations. HPLC and GCMS experiments were performed to examine the degradation fragments of RhB and draw a plausible mechanistic pathway which showed that RhB degradation generated a series of N-deethylated products, followed by a one-time ring-opening, which indicated that photosensitization induced a photocatalysis reaction mechanism.

Prevalence and implications of microplastics in potable water system: An update.

Synthetic plastics, which are lightweight, durable, elastic, mouldable, cheap, and hydrophobic, were originally invented for human convenience. However, their non-biodegradability and continuous accumulation at an alarming rate as well as subsequent conversion into micro/nano plastic scale structures via mechanical and physio-chemical degradation pose significant threats to living beings, organisms, and the environment. Various minuscule forms of plastics detected in water, soil, and air are making their passage into living cells. High temperature and ambient humidity increase the degradation potential of plastic polymers photo-catalytically under sunlight or UV-B radiations. Microplastics (MPs) of polyethylene terephthalate, polyethylene, polystyrene, polypropylene, and polyvinyl chloride have been detected in bottled water. These microplastics are entering into the food chain cycle, causing serious harm to all living organisms. MPs entering into the food chain are usually inert in nature, possessing different sizes and shapes. Once they enter a cell or tissue, it causes mechanical damage, induces inflammation, disturbs metabolism, and even lead to necrosis. Various generation routes, types, impacts, identification, and treatment of microplastics entering the water bodies and getting associated with various pollutants are discussed in this review. It emphasizes potential detection techniques like pyrolysis, gas chromatography-mass spectrometry (GC-MS), micro-Raman spectroscopy, and fourier transform infrared spectroscopy (FT IR) spectroscopy for microplastics from water samples.

Photo-Fenton assisted AgCl and P-doped g-C3N4 Z-scheme photocatalyst coupled with Fe3O4/H2O2 system for 2, 4-dimethylphenol degradation.

In this study graphitic carbon nitride (g-C3N4 or GCN) and phosphorus doped graphitic carbon nitride (p-g-C3N4 or PCN) were prepared using facile thermal polycondensation method. Phosphorus doping was employed to preserve the non-metallic nature of GCN. The AgCl/PCN/Fe3O4 heterojunction was synthesized using a simple in-situ route. The photocatalytic performance of the GCN, PCN, Fe3O4 and AgCl/PCN/Fe3O4 was tested towards 2, 4-dimethylphenol (DMP) pollutant. The work explored improvement in physiochemical properties and reduction of band gap of GCN after P doping (through Tauc's plot method). Coupling with AgCl (silver halide) also enhanced photoinduced charge carriers' separation and migration ability due to apt band alignment among both AgCl and PCN photocatalysts which resulted in formation of direct Z-scheme charge transfer mechanism. Similarly, the incorporation of ferrimagnetic material i.e. Fe3O4 enhanced the generation of hydroxyl (•OH) radicals via photo-Fenton process and facilitated photocatalysts easy separation from the aqueous medium. Through PL and EIS analysis the enhanced charge separation and migration ability in AgCl/PCN/Fe3O4 nanocomposite was validated. The attained DMP degradation efficiency of photo-Fenton assisted AgCl/PCN/Fe3O4/H2O2 Z-scheme nanocomposite was much higher i.e. 99% compared to other photocatalysts within 60 min of visible light irradiation following pseudo-first-order kinetics. Electron paramagnetic resonance (EPR) and scavenging tests confirmed the substantial role of •OH and •O2- radicals in the photo-Fenton reaction. Furthermore, liquid chromatography-mass spectrometry (LC-MS) analysis detected the generated oxidative products and mineralization pathways associated with DMP degradation. The proposed direct Z-scheme charge transfer route presented efficient charge separation and migration ability in AgCl/PCN/Fe3O4 nanocomposite. Recycle ability of the fabricated AgCl/PCN/Fe3O4 photocatalyst was tested up to 5 cycles with 90% removal efficacy, confirming the excellent reusability and stability of AgCl/PCN/Fe3O4 photocatalyst.

Recent advances in Metal Organic Framework (MOF)-based hierarchical composites for water treatment by adsorptional photocatalysis: A review.

Architecting a desirable and highly efficient nanocomposite for applications like adsorption, catalysis, etc. has always been a challenge. Metal Organic Framework (MOF)-based hierarchical composite has perceived popularity as an advanced adsorbent and catalyst. Hierarchically structured MOF material can be modulated to allow the surface interaction (external or internal) of MOF with the molecules of interest. They are well endowed with tunable functionality, high porosity, and increased surface area epitomizing mass transfer and mechanical stability of the fabricated nanostructure. Additionally, the anticipated optimization of nanocomposite can only be acquired by a thorough understanding of the synthesis techniques. This review starts with a brief introduction to MOF and the requirement for advanced nanocomposites after the setback faced by conventional MOF structures. Further, we discussed the background of MOF-based hierarchical composites followed by synthetic techniques including chemical and thermal treatment. It is important to rationally validate the successful nanocomposite fabrication by characterization techniques, an overview of challenges, and future perspectives associated with MOF-based hierarchically structured nanocomposite.

Recent advances in cellulose supported photocatalysis for pollutant mitigation: A review.

In recent times, green chemistry or "green world" is a new and effective approach for sustainable environmental remediation. Among all biomaterials, cellulose is a vital material in research and green chemistry. Cellulose is the most commonly used natural biopolymer because of its distinctive and exceptional properties such as reproducibility, cost-effectiveness, biocompatibility, biodegradability, and universality. Generally, coupling cellulose with other nanocomposite materials enhances the properties like porosity and specific surface area. The polymer is environment-friendly, bioresorbable, and sustainable which not only justifies the requirements of a good photocatalyst but boosts the adsorption ability and degradation efficiency of the nanocomposite. Hence, knowing the role of cellulose to enhance photocatalytic activity, the present review is focused on the properties of cellulose and its application in antibiotics, textile dyes, phenol and Cr(VI) reduction, and degradation. The work also highlighted the degradation mechanism of cellulose-based photocatalysts, confirming cellulose's role as a support material to act as a sink and electron mediator, suppressing the charge carrier's recombination rate and enhancing the charge migration ability. The review also covers the latest progressions, leanings, and challenges of cellulose biomaterials-based nanocomposites in the photocatalysis field.