Search

The present work is centred around the development of La 2 O 3 /(BiO) 2 CO 3 /Ag 3 PO 4 (LBA), a p-n-p nano-heterojunction to photodegrade doxycycline under visible light irradiation. Here, ultrasonication assisted co-precipitation method was employed to synthesize the photocatalyst. The photocatalyst was characterized using different analysis such as SEM, TEM, elemental mapping, XRD, XPS, FTIR, Raman, BET, DRS, PL and EIS which confirmed the successful fabrication of LBA and their excellent ability to refrain the e−/h+ recombination owing to the construction of the heterojunction. LBA was found to degrade DOX by 91.75 % with the high mineralization of 87.23%. The impact of the reaction parameters influencing the photodegradation process including the concentration of the NCs and DOX, pH and the influence of the commonly present anions were studied. The stability and reusability of the LBA was assessed through subjecting it to four cycles of photodegradation of DOX. In addition, the recovered LBA was characterized through XPS and XRD analysis to confirm the particles stability and reusability. The active participation of the photogenerated charges and the reactive oxygen species were identified through the scavenging assay and ESR analysis. Further, GC-MS/MS analysis was performed to put forward a plausible photodegradation pathway. The toxicity of the end products as well as the intermediates was predicted through ECOSAR software. [Display omitted] • LBA nano-hetrojunctionwas prepared via ultrasonication assisted co-precipitation method. • The photodegradation of doxycycline was found to be 91.75 %. • •OH and h+ were primarily involved in photocatalytic reactions. • The LBA nano-hetrojunction exhibited excellent photostability and reusability. • The degradation pathway was elucidated by GC-MS/MS analysis. [ABSTRACT FROM AUTHOR]

Today, a major concern associated with the environment is the water pollution occurred due to the introduction of variety of persistent organic pollutants and residual dyes from different sources (e.g., dye and dye intermediates industries, paper and pulp industries, textile industries, tannery and craft bleaching industries, pharmaceutical industries, etc.) into our natural water resources. Recently, advanced oxidation processes (AOPs) by photocatalyst have garnered great attention as a new frontier promising eco-friendly and sustainable wastewater treatment technology. Utilization of the photocatalytic technology efficiently is significant for cleaner environment. Bismuth based photocatalyst have aroused widespread attention as a visible light responsive photocatalyst for waste water treatment due to their non-toxicity, low cost, modifiable morphology, and outstanding optical and chemical properties. In this review, we have dealt with the research progress on bismuth-based photocatalysts for waste water treatment. However, it seems to give limitation over pristine photocatalysts such as slow migration of charge carriers, charge carrier recombination, low visible light absorption, etc., Various bismuth based photocatalyst and its modifications via doping, heterojunction, Z-scheme etc., are discussed in detail. Further, the strategies adopted to improve the photocatalytic activity of bismuth based photocatalyst to improve the waste water treatment (mostly drugs and dyes) are critically reviewed. Also, we have discussed the bacterial inactivation by bismuth based photocatalyst. Finally, the challenges and future aspects against bismuth based photocatalyst are explored for further research. [Display omitted] • Bismuth based photocatalyst are used for the efficient treatment of waste water. • Addressed issues relating to water pollution and effluent treatment using photocatalysis process. • Modified strategies and defect regulations for effective degradation of toxic pollutants. • Application of bismuth based photocatalyst on treating pollutants, antimicrobial activity and Cr (VI) reduction. • A limitation and future aspect of bismuth based photocatalyst is discussed. [ABSTRACT FROM AUTHOR]

The global health landscape is increasingly threatened by antimicrobial resistance, prompting a search for pioneering interventions. The current study focused on the construction of non-metal doped SnO 2 nanorod decorated with Fe 3 O 4 nanospheres through hydrothermal techniques. The prepared N/S-SnO 2 @Fe 3 O 4 nano-heterojunction was evaluated by performing photocatalytic degradation of tetracycline (TET) under visible light illumination. Out of various combinations tested, S-SnO 2 @Fe 3 O 4 nano-heterojunction was found to degrade TET by 98.3% with a TOC removal of 97%. S-SnO 2 @Fe 3 O 4 nano-heterojunction and its constituents were characterized by using TEM, SEM, XRD, DRS, PL, Raman, XPS, EIS, BET and FTIR. The influence of factors such as pH, ions, S-SnO 2 @Fe 3 O 4 dosage and TET concentration on photodegradation were investigated. Furthermore, the stability and reusability of S-SnO 2 @Fe 3 O 4 nano-heterojunction were assessed through six consecutive cycles of TET photodegradation. XPS and XRD analyses characterized the recovered nano-heterojunction, while scavenging assays and ESR analysis identified as •OH is the main reactive oxygen species involved in TET photodegradation. Additionally, GC-MS/MS analysis proposed a photodegradation pathway, and ECOSAR was used to predict the toxicity of intermediates. • N/S-SnO 2 @Fe 3 O 4 nano-hetrojunction was prepared by hydrothermal method. • The photodegradation of tetracycline was 98.3% with high mineralization of 97%. • •OH and h+ are involved in photocatalytic reactions. • The S-SnO 2 @Fe 3 O 4 nano-hetrojunction exhibited excellent photostability and reusability. • The degradation pathway was elucidated by GC-MS/MS analysis. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) are a distinct class of porous, crystalline materials with excellent photocatalytic activity. These inorganic-organic hybrids have gathered much attention because of their unique properties such as high surface area, vast structural diversity, pore surface characteristics, modifiable framework morphology and semiconductor nature. The synergistic effect provided by the customisable building blocks of MOFs has made them ideal candidates for designing versatile photocatalysts with superior performance. Hence, it becomes vital to present a glance of the recent breakthroughs in the development of various MOF-based photocatalysts to improve the pullbacks in this research area. This review gives an overall picture of the diverse range of MOF-based photocatalysts. The strategies that have been adopted to boost their photocatalytic activity such as post-synthetic modification (PSM), heterojunction designing, doping, introduction of co-catalysts, ligand or substituent functionalization, modulation of metal-oxidation state and bandgap engineering also been explained. Further, the review focuses on the early research developments, structural diversity, synthesis methods, cleaner production and the recent developments in MOF-based photocatalysts for various photocatalytic applications including hydrogen production, CO 2 conversion, photodegradation, photo electrochemical reaction (PEC), oxygen evolution reaction (OER) and fabrication of MOF-derived compounds. Finally, the futuristic challenges and scopes of MOFs as photocatalysts have been discussed. [Display omitted] • MOFs based photocatalysts for environmental remediation and clean energy production. • The strategies to boost their photocatalytic performance are explained. • Photocatalytic applications such as CO 2 conversion, H 2 production, etc are critically reviewed. • The futuristic challenges and research gaps in this area are discussed. [ABSTRACT FROM AUTHOR]

A morphological oriented highly active Cu 2 O–Ag–CaWO 4 (CAC) nano-heterojunction was fabricated for the visible light driven degradation of rifampicin (RFP). Octahedron shaped Cu 2 O being a base material, where the Tagetes shaped CaWO 4 and Ag were embedded on it. The shape-controlled morphology of Cu 2 O and CaWO 4 as well as Ag decoration influence high degree of adsorption of RFP and interfacial charge transfer between the nano-heterojunction. Further, the larger specific surface area (129.531 m2/g) and narrow band gap energy (2.57 eV) of CAC nano-heterojunction than the controls support the statement. Positively, CAC nano-heterojunction following Z-scheme-type charge transport mechanism attained 96% of RFP degradation within 100 min. O 2 •- and •OH are the primarily involved reactive oxidation species (ROS) during the photocatalytic reactions, determined by scavenger study and ESR analysis. The stability and reusability of the CAC nano-heterojunction was assessed through performing cyclic experiment of RFP degradation and it holds 96.8% of degradation even after 6th cycle. The stability of CAC nano-heterojunction after photodegradation was further confirmed based on crystalline pattern (XRD analysis) and compositional states (XPS analysis). Intermediates formed during RFP degradation and its toxicity was discovered by using GC-MS/MS and ECOSAR analysis respectively. The end-product toxicity against bacterial system and genotoxicity of CAC nano-heterojunction against Allium cepa were evaluated and the results were seemed to have no negative causes for the aquatic lives. • CAC nano-heterojunction with Z-scheme-type charge transport mechanism was fabricated for RFP degradation. • CAC nano-heterojunction attained 96% of RFP degradation within 100 min. • O 2.•- and •OH are the primarily involved ROS during the photocatalytic reactions. • Degradation pathway was proposed using GC-MS/MS analysis. • Toxicity studies against bacterial system and Allium cepa was employed. [ABSTRACT FROM AUTHOR]

In this work, a simple g-C 3 N 4 quantum dots enriched MoO 3 nanohybrid was formulated for the synergistic photocatalytic degradation of an industrially active organic pollutant, p-chlorophenol (PCP) and a widely prescribed antibiotic, rifampicin (RIF). The nanohybrid was synthesised via a facile ultrasonic assisted hydrothermal method and characterized using various characterization analysis. The efficient Z-scheme charge transfer of the nanohybrid resulted in the elimination of 98% PCP and 89% RIF under visible light with a rate constant of 0.012 and 0.006 min−1 respectively. The photocatalysis was attributed to the formation of both hydroxyl (OH•) and superoxide (O 2 •-) radicals in the resulting nanohybrid. The intermediates formed in the course of reaction were estimated through gas chromatography-mass spectroscopy/mass spectroscopy (GC-MS/MS) analysis and a suitable degradation pathway was constructed. The structural stability and reusability of the nanohybrid was affirmed through X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis to outweigh the industrial potential of the catalyst, with 85% PCP and 80% RIF removal efficiency after six cycles of degradation. In addition, the mineralization of the pollutants was confirmed by total organic carbon analysis. Further, the toxicity of the drug and the formed intermediates was determined using ecological structure activity relationships (ECOSAR) software. On the whole, this work provides an excellent insight for the development of environment-friendly materials in a large scale for the degradation of water-based pollutants. [Display omitted] • A novel g-C 3 N 4 QDs incorporated MoO 3 catalyst was successfully fabricated. • Superior degradation of about 98% p-chlorophenol and 89% rifampicin was achieved in 330 min. • Led to the mitigation of charge carriers and improved visible light activity. • Porous nature of g-C 3 N 4 QDs facilitated more surface-active sites for efficient adsorption. • Exhibition of Z-scheme mechanism with both.•OH and •O 2 − radicals responsible for photocatalysis. [ABSTRACT FROM AUTHOR]

Novel ZnS–Cu 7 S 4 nanohybrid supported on chitosan matrix, as an ideal photocatalyst, was fabricated by the sonochemical method wherein high-resolution transmission electron microscopy (HRTEM) and X-ray powder diffraction (XRD) analysis confirmed the co-existence of both ZnS and Cu 7 S 4 ; presence of vacancy sites in ZnS was verified by electron paramagnetic resonance (EPR) analysis and their introduction could promote two-photon excitation facilitated visible light response and charge transport/separation. The type II interface is formed in the ZnS–Cu 7 S 4 /Chitosan heterojunction owing to interstitial states that promote charge separation. The ZnS–Cu 7 S 4 /Chitosan was used for the photodegradation of a pharmaceutical pollutant, p -chlorophenol (PCP); over 98.8% of PCP photodegradation was achieved under visible-light irradiation where the ensued ·O 2 − and ·OH serve a key role in the photodegradation of PCP. In vitro cytotoxicity studies substantiated that the ZnS–Cu 7 S 4 /Chitosan is nontoxic to the ecosystem and human beings and endowed with promising photodegradation properties and accessibility via an environmentally friendly design, bodes well for its potential remediation applications. [Display omitted] • ZnS–Cu 7 S 4 /chitosan type II heterojunction showed 98.8% photodegradaion of p-chlorophenol. • Defect engineering to promote synergistic charge separation and visible-light absorption. • The Cu 7 S 4 and ZnS NPs appears to be in spine and nanocube shaped. • Formation of both ·O 2 − and ·OH radicals to boost pollutants degradation. • The In vitro cytotoxicity assay suggests that ZnS–Cu 7 S 4 /chitosan is non-toxic. [ABSTRACT FROM AUTHOR]

Photocatalysis is a reliable technology to treat polluted wastewater. Herein, we report S-scheme photocatalyst namely ZnS/CdS nanocomposites (NCs) with S-vacancies and interstitial defect states, immobilised on the polymer matrix of cellulose and chitosan. It showed significant performance in photocatalytic degradation of Rhodamine B (RhB) dye. Defect sites present in ZnS facilitates charge separation and two-photon excitation concomitantly with a bandgap shift in ZnS/CdS NCs to 2.65 eV and promotes visible light harvesting. XRD analysis demonstrated the highly crystalline nature of the NCs. TEM and SEM were used to observe the crystal phases, particle morphology and defect sites. XPS and EDAX ensured the composition and purity of the synthesized NCs. FTIR displayed the peaks representing the bonds present in metal sulphides and chitosan/cellulose matrix. The photodegradation of RhB by ZnS/CdS NCs reached a maximum of 99.18% in 120 min which displayed 6.8 and 10.25 times higher rate than pure ZnS and CdS respectively. Further, ZnS/CdS NCs was able to achieve the TOC reduction of 86% after the photodegradation of RhB. Defect engineering played a vital role in enhancing the photocatalytic activity of NCs. PL spectra revealed the prolonged life time of photogenerated charge carriers and EIS analysis was used to investigate the charge mobility of the fabricated materials. Superoxide radical was found to be the major radical involved in photodegradation of RhB by NCs. The degradation pathway of RhB was elucidated based on GC-MS/MS analysis. The recyclability of NCs was tested for six consecutive cycles and remarkable stability was observed. The results of in vitro cytotoxicity assay, and cellular reactive oxygen species generation suggest that ZnS/CdS NCs are safety photocatalysts to environment and human being. [Display omitted] S-scheme heterojunction of ZnS/CdS NCs on cellulose/chitosan matrix was fabricated. S-vacancies and interstitial defect states brought in the play of two-photon excitation. This aided bandgap tuning, visible light sensitization and reduced charge recombination. Remarkable Rhodamine B photodegradation of 99.18 % was achieved. In vitro cytotoxicity assay suggested the non-toxic nature of the NCs. [ABSTRACT FROM AUTHOR]

Biosynthesis of nanomaterials using plant extract makes them attractive in the field of photocatalysis as they are environmental friendly. The current study focused on the biosynthesis of ZnO/NiCo 2 S 4 QDs (NCs) using Punica granatum fruit peel extract as the reducing agent. The nanomaterials were characterized with XRD, FTIR, Raman, SEM, TEM, UV–vis DRS, BET, PL, EIS, and ESR analysis and were used for photocatalytic degradation of doxycycline (DOX) and ciprofloxacin (CIP). The bandgap of ZnO is 3.2 eV, and the decoration of NiCo 2 S 4 QDs aids in narrowing the bandgap (2.8 eV), making the NCs visible light active. The fabricated NCs achieved 99 and 89% degradation of DOX and CIP respectively. The photocatalytic efficiency of ZnO/NiCo 2 S 4 QDs was much higher compared to individual ZnO and NiCo 2 S 4 QDs. The half-life period of DOX and CIP were evaluated to be 58 and 152 min respectively. The percentage of TOC removal in the photodegraded product of DOX and CIP was estimated to be 99 and 89% respectively, indicating the mineralization of the compounds. The enhanced photocatalytic efficiency of the NCs was attributed to the narrowed visible light active bandgap, synergistic charge transfer across the interface, and lower charge recombination. The intermediates formed during the photocatalytic degradation of DOX and CIP were analyzed using GC-MS/MS analysis, and the photodegradation pathway was elucidated. Also, the toxicity of the intermediates was computationally analyzed using ECOSAR software. The fabricated ZnO/NiCo 2 S 4 QDs have excellent stability and reusability, confirmed by XRD and XPS analysis. The reusable efficiency of the NCs for the photocatalytic degradation of DOX and CIP were 98.93, and 99.4% respectively. Thus, the biologically fabricated NCs are shown to be an excellent photocatalyst and have wide applications in environmental remediation. [Display omitted] • ZnO/NiCo 2 S 4 QDs photocatalyst was synthesized using P. granatum fruit peel extract. • ZnO/NiCo 2 S 4 QDs showed excellent photocatalytic removal of doxycycline and ciprofloxacin. • The NCs showed excellent stability and reusability. • Photocatalytic mechanism of ZnO/NiCo 2 S 4 QDs and the degradation pathway was proposed. • ZnO/NiCo 2 S 4 QDs can be used as a promising and potential industrial wastewater treatment tool. [ABSTRACT FROM AUTHOR]

Sustainable wastewater treatment is crucial to remediate the water pollutants through the development of highly efficient, low-cost and separation free photocatalyst. The aim of this study is to construct a novel CoNiO 2 –BiFeO 3 –NiS ternary nanocomposite (NCs) for the efficient degradation of organic pollutants by utilising visible light. The NCs was characterized by various physiochemical techniques, including HR-TEM, SEM, XPS, FT-IR, ESR, EIS, PL, UV–visible DRS, and N 2 adsorption and desorption analysis. The photocatalyst exhibits extraordinary degradation efficiency towards MO (99.8%) and RhB (97.8%). The intermediates were determined using GC-MS analysis and the degradation pathway was elucidated. The complete mineralization was further confirmed by TOC analysis. The CoNiO 2 –BiFeO 3 –NiS ternary NCs have shown excellent photostability, structural stability and reusability even after six cycles and it is confirmed by XRD and XPS analysis. The kinetic study reveals that the photodegradation of the dyes follows first order reaction. The influence of different pH, dye concentrations and NCs dosages were investigated. The intermediate toxicity was predicted by computational stimulation using ECOSAR software. The NCs shows promising potential for ecological safety which demonstrates its practical application in the treatment of waste water pollutants in large scale. • A novel CoNiO 2 –BiFeO 3 –NiS ternary nanocomposite (NCs) shows excellent photocatalytic performance. • The synthesized CoNiO 2 –BiFeO 3 –NiS ternary nanocomposite were successfully characterized. • The NCs showed an excellent Z-scheme photocatalytic degradation. • The NCs demonstrated MO (100%) and RhB (96.7%) dye degradation. • The NCs displayed tremendous stability for six photocatalytic cycles. [ABSTRACT FROM AUTHOR]

Research on photocatalysis has boomed in the past two decades as it provides a sustainable solution to degrade organic pollutants. Among the several classes of photocatalyst, metal sulfides have drawn the attention due to its excellent solar spectral response and its notable electrical, optical, mechanical and magnetic properties where MoS 2 serves to be a promising one. Various characteristics of MoS 2 have rendered it as a preferable photocatalyst as well as a co-catalyst to degrade pharmaceutically active compounds (PhACs). Some of its prominent characteristics include its tunable band gap, enhanced absorption of visible light, layered structure, efficient photon-electron conversion, good photostability, non-toxic nature and quantum confinement effects. PhACs are one of the emerging pollutants of great concern which imparts severe effects on aquatic organisms and human health. This review focuses on the degradation of PhACs by the MoS 2 based photocatalysts that has been developed in the recent times. Further, the effect of various parameters that influences the photocatalytic activity of MoS 2 towards PhACs has also been discussed. [Display omitted] • The study highlights the importance of MoS 2 based photocatalysts in PhACs degradation. • Discussed about the properties of MoS 2 and its various synthesis routes. • Highlights the construction and role of MoS 2 based heterojunctions in photodegradation. • Evaluated the effect of various reaction parameters on photodegradation. • Explained the mechanism and photodegradation pathway. [ABSTRACT FROM AUTHOR]

The synthesis of CeO 2 /MnFe 2 O 4 NCs has been carried out by ultrasonication-assisted co-precipitation method. Transmission electron microscopic (TEM) analysis confirmed the embedment of MnFe 2 O 4 over CeO 2 with clear lattice fringes. Energy dispersive analysis (EDAX) and elemental mapping confirm the existence of elements including Ce, Mn, Fe, and O. The XRD patterns of the NCs indicated the effective construction of crystalline CeO 2 /MnFe 2 O 4 NCs with the co-existence of CeO 2 and MnFe 2 O 4 in desired molar ratio. The degradation rate constant of CeO 2 /MnFe 2 O 4 NCs-1:1 under visible light illumination was estimated to be 0.0108 min−1, which was 2.2 and 2.8 times greater than CeO 2 and MnFe 2 O 4 respectively. Here, the study provides a clear insight into the photocatalytic mechanism of the p-n type NCs, which exhibited efficient charge transfer and improved mobility. The scavenging assay and ESR analysis have explicated the major role of •OH radicals as the dominant reactive oxygen species on the photocatalytic degradation of MB dye. The photocatalytic efficiency of CeO 2 /MnFe 2 O 4 NCs-1:1 for MB dye degradation was found to be 86%. The results expressed almost similar degradation efficiency till the 6th cycle and the structural integrity of the NCs was found to be intact even after the photodegradation. Additionally, a predictive degradation pathway for MB was elucidated by Fukui function-based DFT analysis. The anti-microbial activity of the prepared samples was investigated against S. aureus and E. coli. Hence, the fabricated CeO 2 /MnFe 2 O 4 NCs-1:1 was concluded with the obtained results and it has been observed to be a potential candidate as an efficient photocatalyst for the elimination of toxic organic pollutants. [Display omitted] • CeO 2 /MnFe 2 O 4 NCs was synthesized by sono-chemical coprecipitation method. • The CeO 2 /MnFe 2 O 4 NCs showed outstanding visible-light photocatalytic activity. • The NCs demonstrates good photostability and reusability. • The hydroxyl radical was responsible for the enhance photocatalytic activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Z-scheme based nanocatalyst for the enhanced photo catalytic activity. • Enhanced photocatalytic activity by Z-scheme by various nanomaterial. • Effective photocatalytic application of the Z-scheme based nanocatalyst on pollutant removal of pharmaceutical pollutant. • Photocatalyst active sites of PhACs and challenges in photocatalysis. Photocatalysis is the process of exploitation of solar radiation for the creation of a pollution-free stable environment. Photocatalysis has applications in various fields including toxic pollutant degradation, heavy metal reduction, clean energy production (hydrogen generation by water splitting), and CO 2 reduction. Conventional photocatalyst has various shortcomings including poor visible light harvesting and faster charge recombination. The construction of Z-scheme heterojunctions can overcome these shortcomings and solve both the energy crisis and environmental degradation at once. This review is discussed based on the material aspects where interfacial charge transfer and internal electric field play a crucial role in the overall efficiency of a photocatalytic system. Firstly, semiconductors' redox potential and band gap are summarized as they are the key factor in photocatalysis. The charge transfer mechanism such as internal electric field and interfacial defects has been discussed to understand the material design of Z-scheme. Various semiconductor nanoparticles have been used for the construction of the Z-scheme, which has been compared and discussed extensively based on their effectiveness. This review intends to provide up-to-date works in Z-scheme, to guide future developments for better performance and maximum efficiency. [ABSTRACT FROM AUTHOR]

Zinc oxide nanoparticles (ZnO NPs) are largely used in consumer products and industrial applications. The increased use of such materials may lead to its release into the environment. The study used chemically synthesized ZnO NPs and characterized by using UV–visible spectrophotometer, scanning electron microscopy, particle size analyzer and X-ray diffraction (XRD) analysis. The mean diameter of the particles was found to be 55 ± 1.2 nm. The XRD patterns exhibited hexagonal structure for ZnO NPs. The photocatalytic property of ZnO NPs was evaluated based on the UV–vis spectra changes of the methylene blue solution as a function of reaction time in the presence of ZnO NPs under visible light. The study suggests that ZnO NPs can be used as an efficient photocatalyst and the environmental factor such as exopolysaccharides could mask the photocatalytic activity of NPs. [ABSTRACT FROM AUTHOR]

Novel photocatalyst CuO loaded ZnS nanoflower supported on carbon frame work PVA/Chitosan was synthesized by co-precipitation and ultrasonic assisted method. The co-existence of ZnS and CuO and its crystallinity in nanohybrid was verified by XRD, SAED and HR-TEM analysis. The availability of defects in ZnS was identified by EPR. FTIR and TGA verified the presence of PVA and Chitosan. Defects mediated ZnS–CuO/PVA/chitosan heterojunction promote synergistic charge separation with type II interface. Zn-vacancy facilitates two-photon excitation that improves visible-light harvesting. The photocatalytic activity of ZnS–CuO/PVA/Chitosan was 94.7% which is higher when compared to ZnS (40%) and CuO (60%). The photocatalytic mechanism was elucidated using scavenger test and both ·O 2 − and ·OH were found to play key role in tetracycline degradation. In addition, ZnS–CuO/PVA/Chitosan demonstrated efficient anti-microbial effect against the both gram strains on comparing with individual ZnS and CuO. Thus, the multifunctional ZnS–CuO/PVA/Chitosan is promising for the photocatalytic degradation of tetracycline and as an antimicrobial agent. • Zn-vacancy mediated charge separation and visible-light absorption in ZnS–CuO/PVA/chitosan. • Nanoflowers show remarkable tetracycline photo-degradation up to 94.7% without any cocatalyst. • The retention of strong redox potential e−/h+ pairs could afford to generate more ·O 2 − and ·OH radicals. • High photo-degradation by visible light-to-energy efficiency could be achieved for ZnS/CuO. • The nanoflowers showed improved bacterial growth inhibition. [ABSTRACT FROM AUTHOR]

• Mesoporous γ-Al 2 O 3 coupled 2D hexagonal CdO nanoplates as photocatalyst • Prepared using ultrasonic assisted method with good crystallinity • Tailored bandgap energy of CdO/Al 2 O 3 was 2.95 eV with visible light sensitization • Photodegradation of synthetic cationic dye followed first order kinetics • The particles exhibited excellent antibacterial activity The mesoporous network of γ-Al 2 O 3 ceramic support was coupled with the two dimensional (2D) hexagonal CdO nanoplates by ultrasonic assisted method. The fabricated photocatalyst was analyzed for its structural, morphological and optoelectrical properties by employing X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), photoluminescence, electron spin resonance (ESR) analysis and electrochemical impedance spectroscopy (EIS). The X-ray powder diffraction (XRD) result supports the good crystallinity of the fabricated nanohybrid with co-existence of pure phases of γ-Al 2 O 3 and CdO nanoparticles (NPs). The nanohybrid was tailored to narrow down the bandgap to visible-light region. The bandgap energy obtained by UV–visible diffuse reflectance spectroscopy (DRS) for CdO/Al 2 O 3 nanocomposite (NCs) was 2.95 eV. The Brunauer-Emmett-Teller (BET) surface area analysis shows porosity of material with high surface area. During photocatalysis, e- from CdO migrates to defect levels of Al 2 O 3 that facilitated charge separation. The kinetic rate of degradation of methylene blue (MB) by NCs was 3.5 and 14 times higher than CdO and Al 2 O 3 respectively. The performance was optimized and it showed good reusability. In addition, the multiple applications of the CdO/Al 2 O 3 were evaluated by testing the bactericidal activity. The nanohybrid posed high growth inhibition activity towards both gram positive and negative bacterial strains. The maximum colour removal (97.3%) and high mineralization (87%) was verified by UV–visible and total organic carbon (TOC) measurements. This promotes the nanohybrid to act as a better candidate for environmental remediation and disinfectant applications. [ABSTRACT FROM AUTHOR]

• MnS/Ag 2 WO 4 NCs was prepared by chemical co-precipitation method. • The NCs showed efficient visible light photocatalytic activity than individual particles. • MnS/Ag 2 WO 4 showed potent anti-microbial activity against gram positive and gram negative microorganisms. • Experimental results demonstrated that OH• and •O2- are the major reactive species involved in dye degradation. • MnS/Ag 2 WO 4 NCs showed MB dye degradation potency of 92.3%. In this study, the novel MnS/Ag 2 WO 4 photocatalyst was synthesized via chemical co-precipitation method and investigated its physical and structural characteristics using HR-TEM, N 2 adsorption and desorption studies, FT-IR, EDAX, PL, UV–vis DRS, ESR, XPS and XRD. The estimation of photocatalytic activity of synthesized photocatalysts was done using methylene blue (organic dye) in aqueous solution. The photocatalyst efficiency was superior for MnS/Ag 2 WO 4 with degradation of 92.3% when compared with bare MnS (67.23%) and Ag 2 WO 4 (58.93%). The kinetic study reveals that higher reaction kinetic rate achieved by the MnS/Ag 2 WO 4 compared with MnS and Ag 2 WO 4. The scavenging test reveals that •OH and O2-• took the important part in the degradation process. The six cycles test reveals that the photocatalyst is highly reusable by showing similar degradation efficiency throughout the six cycles. MnS/Ag 2 WO 4 was also possessed potential broad spectrum anti-microbial activity against B. subtilis and E. coli. Hence, MnS/Ag 2 WO 4 heterostructure can be used as an excellent photocatalyst as well as an effective anti-microbial agent. MnS/Ag 2 WO 4 would be a cost-effective, highly efficient photocatalyst and a good antimicrobial agent. [ABSTRACT FROM AUTHOR]

• Novel FeV 2 O 4 nanospheres at surface of nanocube-like Bi 2 O 3 were synthesized. • UV-Vis-DRS, HRTEM, EDAX, SAED, XRD, BET, PL, VSM, XPS and FT-IR analysis were performed. • The photocatalytic rate of FeV 2 O 4 -Bi 2 O 3 was enhanced by 4.6–7 folds than pure NPs. • The mechanism of degradation was elucidated based scavenger response. • The FeV 2 O 4 -Bi 2 O 3 exhibited excellent antibacterial activity. Photocatalytic activity of nanocube structured Bi 2 O 3 was enhanced by loading FeV 2 O 4. XRD results reflected the crystalline nature of nanocomposites (NCs) consisting of FeV 2 O 4 and Bi 2 O 3. XPS confirmed the chemical states. FTIR peaks revealed that the M-O bonds had tetrahedral/octahedral structure. The FeV 2 O 4 -Bi 2 O 3 NCs have higher surface area in comparison with its constituent nanoparticles (NPs) which was confirmed using BET analysis. UV-Vis-DRS indicated the band gap shift of NCs to 2.59 eV which enhanced the visible-light sensitization. Optical and magnetic studies were carried out with photoluminescence and VSM analysis. The photocatalytic performance of the NCs was 4.6–7 times higher than that of its individual components. The ·OH is the key species involved in dye-degradation. High mineralization of the contaminants is supported by TOC analysis of degraded product. A stable photocatalytic performance of FeV 2 O 4 -Bi 2 O 3 was observed after six cycles. The growth inhibitory action of NCs against Escherichia coli and Bacillus subtilis confirmed its outstanding antimicrobial activity. The enhanced sunlight harvesting property and magnetic-removable nature have made FeV 2 O 4 -Bi 2 O 3 NCs as a noteworthy material to be applied in aqueous bodies to degrade threatening pollutants through photodegradation and as antimicrobial agent. [ABSTRACT FROM AUTHOR]

CdO/ZnFe 2 O 4 nanohybrid heterostructure was prepared by ultra-sonication assisted chemical precipitation technique in order to impose better separation of charge carriers, high photocatalytic and bactericidal activity. The formed CdO/ZnFe 2 O 4 nanocomposites (NCs) was characterized by UV-Vis-DRS, XPS, SEM, EIS, EDAX, VSM, SAED, HRTEM, FTIR, XRD, photoluminescence (PL) and BET surface area analyzer. CdO/ZnFe 2 O 4 poses narrow bandgap (2.04 eV) that enhanced the light harvesting in visible region. The high surface area of CdO/ZnFe 2 O 4 (53.6 m2/g) relative to CdO (44.9 m2/g) and ZnFe 2 O 4 (20.1 m2/g) provides more active sites that enhances the photocatalysis. The coupling of CdO and ZnFe 2 O 4 improved the life time of charge carriers as confirmed by PL analysis. The photocatalytic performance of NCs was evaluated based on methylene blue dye degradation. The photocatalytic degradation rate by NCs was enhanced 1.2 and 1.4 folds than CdO and ZnFe 2 O 4. VSM results showed super-paramagnetic nature of NCs with saturation of 42.4 emu/g which aids magnetic separation for its reusability. The reusability test of NCs showed almost same efficiency in all the 6 cycles. TOC analysis of degraded product supported high mineralization (71%) of MB. Scavengers' studies indicated the major role of h+ and OH· radical in dye degradation. In addition, CdO/ZnFe 2 O 4 NCs exhibited high antibacterial effect against S. aureus, B. subtils and E. coli. It is proposed that CdO/ZnFe 2 O 4 NCs could be applied as a promising photocatalyst for environmental remediation and as an antimicrobial agent [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, a novel MgS/Ag 2 MoO 4 nanocomposite (NCs) was synthesized for the evaluation of photocatalytic performance and anti-microbial activity. The particle was characterized using FT-IR, PL, HR-TEM, EDAX, XRD, XPS, SAED, UV–vis DRS, ESR, and EIS. The performance of the photocatalyst was improved by shift in band gap to 2.76 eV compared to its individual counter parts. The photocatalytic performance of MgS/Ag 2 MoO 4 NCs was much better than MgS and Ag 2 MoO 4 as individual particles. The reaction rate constant for degrading MB by MgS/Ag 2 MoO 4 was 0.011 min−1. The degradation efficiency of MgS/Ag 2 MoO 4 (90%) was about 1.5 and 2.2 times greater than bare Ag 2 MoO 4 (62%) and MgS (41%). The photocatalytic degradation efficiency remains same with 90% efficiency after performing the reusability test for six consecutive cycles under visible light irradiation and the particles maintained photo stability even after 6 cycles. The strong interactions between the interfacial surfaces are responsible for the increase in charge separation owing to the superior activity of MgS/Ag 2 MoO 4 NCs. The mechanism was established for this enhanced activity and the key reactive species, such as hydroxyl and superoxide radicals plays a major role in the photocatalytic process. The antimicrobial activity was evaluated against E. coli and B. subtilis and the activity of Ag 2 MoO 4 was good compared to NCs and MgS. The synthesized NCs are found to be good alternative as a visible light driven photocatalyst. [Display omitted] • MgS/Ag 2 MoO 4 NCs was synthesized by fast and facile sono-chemical method. • NCs formation improved the photocatalytic activity compared to its individual counter parts. • Achieved an effective interface transfer and separation of photoinduced electrons and holes. • The generation of both super oxide and hydroxyl radicals involved in the photocatalytic degradation. • Excellent antibacterial activity shown against E. coli and B. subtilis. [ABSTRACT FROM AUTHOR]

• Bi 2 MoO 6 /Ag 2 MoO 4 nanocomposite was synthesized with a tuned band gap of 2.89 eV. • Bi 2 MoO 6 /Ag 2 MoO 4 nanocomposite exhibited 91.8% degradation of MB. • Bi 2 MoO 6 /Ag 2 MoO 4 nanocomposite demonstrates good photostability, reusability and antimicrobial activity. • The key reactive species involved in the photocatalytic degradation process was OH. The novel Bi 2 MoO 6 -Ag 2 MoO 4 nano-photocatalyst was prepared via facile sono-chemical route. Bi 2 MoO 6 -Ag 2 MoO 4 nanocomposite was characterized by high-resolution transmission electron microscopy (HR-TEM), fourier transverse infrared spectroscopy (FTIR), X-ray diffraction (XRD), BET surface area analyzer, photoluminescence (PL), X-ray photoelectron spectroscopy and UV–visible diffuse reflectance spectroscopy. XRD and SAED pattern shows that the particles were crystalline in nature. The formation of heterojunction with tuned band gap of 2.89 eV enhanced the photocatalytic performance of nanocomposite under visible light irradiation. Bi 2 MoO 6 -Ag 2 MoO 4 nanocomposite followed the pseudo-first order kinetic and it showed high correlation coefficient value (R2 > 0.95), and it fitted well to the Langmuir–Hinshelwood model. Bi 2 MoO 6 -Ag 2 MoO 4 nanocomposite exhibited 91.8% degradation which was highly effective than individual Ag 2 MoO 4 (54.66%) and Bi 2 MoO 6 (58.6%). The radical trapping study reveals the key reactive species involved in photocatalytic degradation process such as .OH. The Bi 2 MoO 6 -Ag 2 MoO 4 nanocomposite was found to be highly reusable for the degradation of MB dye by showing 91.8% degradation efficiency after 6th cycle. Antimicrobial activity of the Bi 2 MoO 6 -Ag 2 MoO 4 nanocomposite was superior when compared with Ag 2 MoO 4 and Bi 2 MoO 6 nanoparticles. The prepared nanocomposite proved a robust alternative as a solar radiation driven photocatalyst and it also acts as an antimicrobial agent for the treatment of environmental water. [ABSTRACT FROM AUTHOR]

The unreported Bi 6 Cr 2 O 15 -Co 3 O 4 nano-photocatalyst was prepared via facile sono-chemical route for the fabrication of a binary heterojunction. HRTEM analysis represents the spherical and rod-like morphology of Bi 6 Cr 2 O 15 -Co 3 O 4. UV–vis DRS showed bandgap shift from 1.95 eV (Bi 6 Cr 2 O 15) and 2.67 eV (Co 3 O 4) to 2.25 eV for Bi 6 Cr 2 O 15 -Co 3 O 4 with visible-light sensitization. X-ray photoelectron spectroscopy (XPS) confirmed the chemical states (Co2p, Cr2p, Bi4f and O1s). The dye degradation efficiency of Bi 6 Cr 2 O 15 -Co 3 O 4 was highly boosted up to 3.8–8.8 times and the kinetic rate constant was 0.0062 min−1 compared with pristine counter parts (Bi 6 Cr 2 O 15 = 0.0016 min−1; Co 3 O 4 = 0.0007 min−1). The remarkably enhanced photocatalytic activity was ascribed to its higher specific surface area (27.118 m2/g) and the existence of a synergic effect between pristine counter parts that resulted in suitable bandgap and reduced recombination of e-/h+ pairs. The Bi 2 CrO 6 -Co 3 O 4 showed only negligible reduction in degradation performance after six recycles showing its excellent stability and resistance to photo-corrosion. The ·OH and h+ were the key species involved in dye degradation. The Bi 6 Cr 2 O 15 -Co 3 O 4 exhibited excellent antimicrobial activity against Escherichia coli and Bacillus subtilis. Therefore, Bi 6 Cr 2 O 15 decorated Co 3 O 4 nano-photocatalyst can be used as an effective candidate for environmental remediation through photocatalysis and for bactericidal applications. Pictorial representation of Bi 6 Cr 2 O 15 -Co 3 O 4 mechanism [Display omitted] [ABSTRACT FROM AUTHOR]

• The VS 4 /Ag 2 WO 4 were prepared by chemical co-precipitation method. • The photo-degradation activity of MB by VS 4 -Ag 2 WO 4 shows superior activity than the individual counter parts. • VS 4 -Ag 2 WO 4 possessed good stability after 6 cycles. • Excellent antibacterial activity shown by VS 4 -Ag 2 WO 4 against E. coli and B. subtilis. VS 4 /Ag 2 WO 4 nanocomposites (NCs) were synthesized successfully through facile co-precipitation and ultra-sonic assisted methods. VS 4 /Ag 2 WO 4 NCs was characterized by EDAX, UV–vis DRS, HR-TEM, XPS, XRD, PL, FT-IR, and BET surface area analyzer. The TEM image declares that VS 4 /Ag 2 WO 4 NCs are spherical shape with clear facets and narrow size distribution. The elemental composition (V, S, Ag, W and O) of as-prepared NCs was confirmed using EDX. FT-IR study established the loading and incorporation of Ag 2 WO 4 over VS 4. XRD results proved the polycrystalline nature of the prepared NCs and orthorhombic phase of Ag 2 WO 4. The degradation rate constant for MB by VS 4 /Ag 2 WO 4 was 0.0124 min−1 where it is 3.64 and 1.44 times higher than Ag 2 WO 4 (0.0038 min−1) and VS 4 (0.0086 min−1) respectively. The pseudo-first order kinetics was agreed well with degradation process. The photocatalytic mechanism was elucidated based on the scavengers and it was found that generation of •OH by VS 4 /Ag 2 WO 4 under visible light irradiation played the major role. The reusability and photostability were tested by performing consecutive 6 cycles where it retained the same degradation efficiency and crystal structure as same as first. The NCs possessed high antimicrobial activity against gram positive B. subtilis and gram negative E. coli. The information provided by these results confirms the great potential of NCs as a highly efficient photocatalyst for the removal of pollutants from water and as an excellent antimicrobial agent. [ABSTRACT FROM AUTHOR]

Mercury has been considered as the most toxic metal pollutants that pose lethal threat to environment and the human health at small concentrations. Thus, the development of a rapid, inexpensive and simple technique for Hg2+ ion detection in real aqueous samples is paramount. The present study reported a colorimetric assay for sensing Hg2+ ion using Cu sensitized Ag-dextran nanocomposite (NCs) in presence of tyrosine. The particle was characterized by UV–visible (vis) spectrophotometer, zeta sizer, HR-TEM, particle size analyzer, FT-IR, EDAX and XRD. The NCs possessed a hydrodynamic diameter of 26 ± 1.4 nm and − 32.21 ± 3 mV was the zetapotential value. The colour of Ag/Cu NCs was brownish yellow due to the LSPR band centred at 408 nm. An appreciable colour change was observed from yellowish brown to colourless after interaction with Hg2+ ion. A good linearity existed in the correlation curve between the absorbance value (ℷ = 408 nm) and the Hg2+ ion concentrations (20 nM – 100 nM). A simple, low cost paper-strip based sensor of Ag/Cu NCs used as an real time portable Hg2+ detection. The influence of other metal ions, pH (5.0 to 9.0), salinity (0.1–0.8%) and temperature (15–50 °C) for the Hg2+ detection was also investigated. The NCs exhibits high specificity, sensitivity and stability towards the Hg2+ detection at low nano molar level. Additionally, the NCs exhibited excellent MB degradation under irradiation of visible light and it also showed antimicrobial activity against B. subtilis and E. coli. The study demonstrated the application of Cu sensitized Ag-dextran NCs in detection, photocatalysis, and as an antimicrobial agent. Unlabelled Image • The prepared probe was selective towards detection of Hg2+ in real aqueous sample. • Ag Cu nanocomposite showed specificity in detection in the presence of tyrosine. • A simple, low-cost paper strip method was developed to detect Hg2+. • Effect of pH, temperature, salinity and interference of other metal ions were studied. • The particles showed efficient photocatalytic and anti-microbial activity. [ABSTRACT FROM AUTHOR]