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Rapid industrialization demands for effective nano-photocatalyst that works under visible-light irradiation. The effective p–n interfacial engineering in nanoparticles (NPs) offers better photocatalytic performance. High performing nano-heterojunction of intimately coupled n-copper ferrite (CuFe2O4) NPs on p-nickel oxide (NiO) NPs was prepared that mitigates the charge recombination. X-ray diffraction confirmed the coexistence of the rhombohedral NiO and tetragonal CuFe2O4 in the prepared NCs. The bandgap energy of NiO/CuFe2O4 NCs-30 is 2.18 eV which supports visible light photocatalysis. The rate constant for degrading the methylene blue (MB) dye by NiO/CuFe2O4 NCs-30 was about 0.010 min−1 which is 1.42 times and 2 times higher when compared to NiO and CuFe2O4 NPs. The reusability efficiency was 94.54%. It has been found that both OH⋅ and ⋅O2− radical formed and contributed in degrading MB dye. The importance of the prepared NCs can be understood from its effective performance and it can be concluded that it has high photocatalytic potential to degrade the aquatic pollutants. [ABSTRACT FROM AUTHOR]

The development of low-cost, efficient and sustainable technology is considered to be of paramount for the efficient degradation of toxic pollutants. The research in this report constructs an S-scheme heterojunction CoO/ZnFe2O4 nanocomposite (NCs) with outstanding photocatalytic performance on methylene blue (MB) dye degradation under visible light illumination. Several techniques were used for nanoparticles (NPs) and NCs to determine their morphological, structural, and optical properties. The CoO/ZnFe2O4 NCs (88.5%) exhibited excellent photocatalytic activity compared to the pristine CoO (66.8%) and ZnFe2O4 (64.3%). The total organic carbon (TOC) analysis confirmed that the MB dye was completely mineralised by the as-prepared NCs. From the results of the GC-MS/MS analysis, a possible intermediate formation and degradation pathway was identified. The h+ and ˙OH are the free radicals which primarily dominate the photocatalytic process. A recyclability study performed on the CoO/ZnFe2O4 NCs revealed that it was an extremely stable catalyst, even after six cycles, without substantial decreases in its degradation activity. The intermediate toxicity was predicted using ECOSAR software and the results confirmed the non-toxicity of the end product formed during the degradation of the MB dye. [ABSTRACT FROM AUTHOR]

With increasing use of antibiotics, the development of antibiotic-resistant pathogens poses a serious threat to human health and the environment. Photocatalytic inactivation of these harmful pathogens is one of the novel and non-antibiotic treatments. The study fabricated Ag NPs decorated CdZnS QDs via a facile and biological co-precipitation method using L. camara plant extract as a green alternative to treat the toxic chemicals. The fabricated Ag/CdZnS QDs (NCs) were prepared for the efficient treatment of antibiotic-resistant pathogens as they raise a major global concern. The fabricated NCs were characterized with various characterization techniques to verify its physicochemical properties. The fabricated NCs have shown excellent photo-sterilization performance of 97 % against S. aureus. The excellent activity was attributed to the decoration of Ag NPs on CdZnS QDs as it helped in shortening band gap, improved visible light absorption ability, increased active sites, and boosted photogenerated electron/hole pairs stability. Radical trapping experiment and ESR analysis indicated the involvement of •OH and h+ in the photoinactivation of bacteria. The photo sterilization reaction of NCs was carried out under different environmental conditions, including light and dark conditions and different pH conditions. The experiment was carried out in sewage-treated water in order to test the real-time application, and the fabricated NCs achieved excellent 95.9 % photo-inactivation of S. aureus cells in sewage treated water and the Chemical Oxygen Demand (COD) of the system was increased after photo inactivation treatment. The fabricated NCs have also shown excellent reusable efficiency of 95% after six runs and the photostability and anti-corrosive nature of NCs were confirmed. The study provides an insight for the employment of photocatalysis for the sterilization of pathogens in real time aquatic environment across the globe. [Display omitted] [ABSTRACT FROM AUTHOR]

Focusing at efficient Cefixime (CEFX) removal, a delicate ultrathin-Bi 2 WO 6 (UBWO) stacked quasi-CoFe 2 O 4 binanosheets (BT) were meticulously designed and integrated with spherical MnWO 4 (MWO) and carbon quantum dots (CQDs), forming a n-p-n CQDs@MWO/CFO:UBWO nanohybrid. XRD, XPS, TEM and other systematic analysis demonstrated the vertically aligned layer by layer assembly of UBWO:CFO BT, and a shift in the highly exposed (211) facet of UBWO after nanohybrid formation as well as large surface area (323.33 m2/g) was achieved. UV–vis DRS, PL and EIS proved high separation efficiency, prolonged life time and photogeneration of more charge carriers with absorption of full light spectrum. As expected, the optimized 5 %CQDs@0.25MWO/0.1CFO:UBWO nanohybrid displayed excellent visible light absorption and outstanding CEFX photodegradation whose kinetic constant were 21.11, 12.5, 8.82 folds higher than UBWO, CFO and MWO counterparts. This enhanced photodegradation performance ascribed to the dual strategy as follows: (i) Cascaded charge transfer with the Built-in electric field (BIEF) after n-p-n heterojunction, (ii) the upconverted PL and the electron reservoir properties of CQDs. Degradation efficiency maintained over six consecutive cycles affirming the superior recyclability of the photocatalyst. A possible degradation pathway was proposed based on GC-MS/MS analysis and the end products toxicity were systematically predicted using ECOSAR program. The toxicity of the end product was investigated against bacterial species. The proposed work provides a novel way for the fabrication of efficient photocatalyst with excellent practical applicability. [Display omitted] • UBWO/CFO binanosheets interfaced MWO synergistic with CQDs fabricated via hydrothermal method. • Optimized 5 %CQDs@ 0.25MWO/0.10CFO:UBWO showed high photodegradation efficiency. • Excellent recyclability demonstrated by the cyclic degradation experiments. • •OH and O 2 •- radicals played major role in the photodegradation process. • Non-toxic nature of end product affirmed by ECOSAR and bacterial studies. [ABSTRACT FROM AUTHOR]

The work attempts to construct a highly effective γ-Bi 2 O 3 /CoFe 2 O 4 /Ag visible active photocatalyst for the enhanced degradation of ciprofloxacin (CIP) and Cr(VI) reduction. γ-Bi 2 O 3 /CoFe 2 O 4 /Ag photocatalyst was prepared by simple solid phase and co-precipitation methods. The nanosphere shaped CoFe 2 O 4 photocatalyst are embedded on top of γ-Bi 2 O 3 nanotriangle. The addition of Ag into γ-Bi 2 O 3 /CoFe 2 O 4 heterojunction primitively facilitates the photocatalytic activity in higher rate. The quantitative analysis of photocatalyst possesses to have lower e−/h+ recombination rate compared to its counterparts. The prepared γ-Bi 2 O 3 /CoFe 2 O 4 /Ag photocatalyst showed 96.6% degradation of CIP in 220 min and 99.2% reduction of Cr(VI) in 120 min. Additionally, γ-Bi 2 O 3 /CoFe 2 O 4 /Ag showed outstanding recyclability and long-term stability with a degradation efficiency of 96.5% even after six cycles. The intermediate products formed were identified and the degradation pathway was elucidated by gas chromatography-mass spectrometry analysis. Total organic carbon measurement was carried over to assess the efficiency of complete degradation and the removal percentage was found to be 98%. The end product toxicity study towards bacteria was proven to have less toxicity level when compared to parent compound. Lastly, the genotoxicity of γ-Bi 2 O 3 /CoFe 2 O 4 /Ag photocatalyst was tested in Allium cepa and the results confirmed to have no cause of toxicity impacts. Overall, the work not only tends to provide a highly visible active γ-Bi 2 O 3 /CoFe 2 O 4 /Ag photocatalyst, but also attributes to have no further negative imprints in the environment. [Display omitted] • γ-Bi 2 O 3 /CoFe 2 O 4 /Ag photocatalyst was fabricated via solid phase and co-precipitation routes. • The particle exhibited enhanced photocatalytic degradation of ciprofloxacin and Cr(VI) reduction. • The degradation pathway of ciprofloxacin was elucidated by GC-MS/MS analysis. • The photocatalyst possess outstanding recyclability and stability. • Genotoxicity result of photocatalyst was determined by using Allium cepa. [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]

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]

Pharmaceutical pollutant in the environmental water bodies has become a major concern, which causes adverse effect to aquatic entities. This study provides an incisive insight on the photocatalytic degradation of ciprofloxacin (CIP) and the development of rationally engineered g–C 3 N 4 –NiCo 2 O 4 –Zn 0.3 Fe 2·7 O 4 nanocomposite for boosted photocatalytic performance under visible light irradiation. The g–C 3 N 4 –NiCo 2 O 4 –Zn 0.3 Fe 2·7 O 4 nanocomposite was synthesized via ultrasonication-assisted hydrothermal method. The characterization of the as-prepared material was evaluated by XPS, SEM, HR-TEM, PL, FT-IR, EIS, ESR, XRD, BET, and UV–Vis DRS techniques. Furthermore, the effect of catalytic dosage, drug dosage, and pH changes was explored, where g–C 3 N 4 –NiCo 2 O 4 –Zn 0.3 Fe 2·7 O 4 -10% unveiled excellent visible light photo-Fenton degradation of 92% for CIP at 140 min. The hydroxyl radicals (OH.) served as the predominant radical species on the photodegradation of CIP, which was confirmed by performing a radical scavenging test. Furthermore, the degradation efficiency was determined by six consecutive cycle tests, where the nanomaterial exhibited excellent stability with 98.5% reusable efficiency. The degradation of CIP was further scrutinized by GC-MS analysis, where the degraded intermediate products and the possible pathway were elucidated. The degraded product toxicity was determined by ECOSAR program, where the degraded products haven't exhibited any considerable toxic effects. In addition, the genotoxicity of the nanomaterial was determined by treating them with root tips of A. cepa , where it was found to be non-toxic. Here, the prepared g–C 3 N 4 –NiCo 2 O 4 –Zn 0.3 Fe 2·7 O 4 nanocomposite (CNZ NCs) shows eco-friendly and excellent photo-Fenton activity for environmental applications. [Display omitted] • A dual Z – scheme based visible-light driven ternary g–C 3 N 4 –NiCo 2 O 4 –Zn 0.3 Fe 2·7 O 4 nanomaterial was successfully synthesized. • The effect of operating parameters on ciprofloxacin degradation was investigated. • A possible degradation pathway of ciprofloxacin has been proposed based on GC-MS/MS analysis. • The degraded intermediates have been screened for chronic and acute toxicity effects by QSAR method. • g–C 3 N 4 –NiCo 2 O 4 –Zn 0.3 Fe 2·7 O 4 explicated non-toxic nature upon treatment with Allium cepa. [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]

• CaFe 2 O 4 -ZnO nanocomposite was constructed by chemical co-precipitation method. • Photocatalysis rate of NCs was 13.5 and 9 folds higher than pristine CaFe 2 O 4 and ZnO. • Photoluminescence study revealed the reduced recombination rate of e−/h+ pairs. • The OH· radical is the dominant species in dye degradation. • The nanohybrid exhibited excellent antibacterial activity. Environmental pollution demands the fabrication of suitable nano-photocatalyst that works under white-light irradiation. The effective interfacial engineering is required for better separation of charges. Here, the novel magnetic CaFe 2 O 4 -ZnO nanophotocatalyst was synthesized by adopting a sonochemical method. The CaFe 2 O 4 -ZnO was analyzed using HRTEM, XRD, FTIR, BET, UV-visible DRS, BET, EIS, and photoluminescence analysis. The photocatalytic performance of CaFe 2 O 4 -ZnO is evaluated by decolourization of Rhodamine B (RhB). Further, the particles' multifunctionality was evaluated by testing its antibacterial activity against Bacillus subtilis and Escherichia coli under dark and light. Here, 97.5% of RhB (25 mg/L) was degraded by CaFe 2 O 4 -ZnO (60 mg/L) under visible light. The kinetic rate of photocatalysis by CaFe 2 O 4 -ZnO was 0.027 min−1 which was 13.5 and 9 folds higher relative to pristine CaFe 2 O 4 and ZnO. At pH 9, the RhB displayed higher photodegradation. Trapping experiments indicate · OH radical severe a key role in RhB degradation. The formation of p-n interface boosted better charge separation and improved ROS generation. At 50 mg/L CaFe 2 O 4 -ZnO, the antibacterial performance under light was 98% against B. subtilis and 99.9% against E. coli. The present study reports CaFe 2 O 4 -ZnO nanophotocatalyst for the effective environmental remediation through photocatalysis and as an antibacterial agent. Photocatalytic mechanism of CaFe 2 O 4 -ZnO nanocomposite. [Display omitted] [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]

The CdS/Ag 2 S nanocomposites (NCs) were synthesized by chemical co-precipitation technique. The optical properties and multifunctionality of the NCs were studied by evaluating photoluminescence, photocatalytic, antibacterial and anti-biofilm properties. The microscopic image indicated that the prepared CdS/Ag 2 S NCs were spherical shaped. The scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis indicates the successful formation of CdS/Ag 2 S NCs which were in nano-size. Brunauer–Emmett–Teller (BET) surface area analysis indicates the high surface area (57.23 m²/g) of NCs with narrow pore size. On comparison with pure Ag 2 S NPs (1.62 eV), CdS/Ag 2 S NCs bandgap had shift to 2.12 eV which facilitates visible light sensitization. The energy-dispersive X-ray spectroscopy (EDAX) analysis provides chemical composition details and possible electronic states observed via XPS core level scan of Ag3d, Cd3d and S2p. The activity of CdS/Ag 2 S NCs photocatalyst was estimated based on methylene blue (MB) dye degradation by irradiating under visible light. NCs showed excellent photocatalytic activity and at pH 8, the particles showed 95 ± 2.4% degradation of MB in 60 min. The ·O 2 - radical played key role in MB degradation. The CdS/Ag 2 S NCs exhibited a stable photocatalytic performance after six cycles. Total organic carbon (TOC) analysis of degraded product supported high mineralization of the pollutants. The NCs showed good antibacterial property against S. aureus and E. coli. The precoated CdS/Ag 2 S NCs showed greater inhibition in biofilm formation. CdS/Ag 2 S NCs also showed toxic effect on formed biofilm under dark and light condition. The research work testified that CdS/Ag 2 S NCs have potential applications in environmental treatment and antimicrobial applications. Possible photocatalytic mechanism of CdS/Ag2S [Display omitted] [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]

The present work highlights the preparation of double Z-scheme ZnCo 2 O 4 /MnO 2 /FeS 2 nanocomposite (NCs) and investigated its photocatalytic activity against methyl orange (MO) dye degradation under visible light. An array of techniques was carried out to characterize the nanoparticles (NPs) in order to evaluate their morphological, structural, optical, and photocatalytic properties using FE-SEM, TEM, XRD, N 2 adsorption and desorption studies, PL, UV–visible spectrophotometer, XPS, Raman, and UV–vis DRS analysis. The degradation efficiency of NCs was tested along with different parameter studies such as different pH, NCs concentration, dye concentration, reusability and structural stability. The NCs exhibited complete photodegradation of MO dye under visible light within 80 min at pH 4. The structural and compositional stability of the prepared NCs over 6 consecutive cycles was tested via XRD and XPS analysis. The results of active species trapping experiments showed that O2−• and OH• are responsible for the degradation of MO dye. The TOC analysis showed 95% of mineralization by the prepared NCs. The MO dye degradation pathway was determined using GC-MS/MS analysis and drafted all the intermediates involved. End product toxicity via seed germination and intermediate toxicity study using ECOSAR software results in less toxicity of end product compared to parent compound. Finally, the genotoxicity of the prepared NCs was evaluated using Allium cepa and showed its no causes of cytotoxicity & genotoxicity by the prepared NCs. ZnCo 2 O 4 /MnO 2 /FeS 2 NCs exhibited its high photocatalytic activity and the toxicity studies confirms that there is no cause of any environmental impact. [Display omitted] • Double Z-scheme heterojunction system of ZnCo 2 O 4 /MnO 2 /FeS 2 NCs was constructed. • The 96% photodegradation of methyl orange observed at pH 6. • TOC removal was found to be 95% at pH 6. • Degradation pathway was elucidated based on GC-MS/MS analysis. • The end product toxicity was evaluated via seed germination using Vigna radiata seeds. [ABSTRACT FROM AUTHOR]

The development of an efficient and robust photocatalyst is of great importance for the effective treatment of toxic pollutants. In this study, novel Ag 3 PO 4 microspheres were decorated on the nanorod embedded flower-like BiOBr designed for the effective photodegradation of methyl orange (MO) and malachite green (MG) dyes. The synthesized particle was characterized to understand the structural and morphological features using HR-TEM, XRD, SEM, PL, ESR, FT-IR, XPS, EIS and N 2 adsorption and desorption. The degradation rate constants for MG (0.0132 min−1) were 3.47 and 3.14 times greater than BiOBr and Ag 3 PO 4. Similarly, the rate constants for MO degradation (0.0151 min−1) are 3.87 and 3.97 times greater than BiOBr and Ag 3 PO 4. The effect of initial MG and MO dye concentration, reaction pH, nanocomposite (NC) concentration was investigated. The NC exhibited excellent visible light photodegradation of 99.8% for MO and 93.4% for MG dyes at 180 min and 200 min respectively. A S-scheme heterojunction were proposed as the possible mechanism for the photodegradation of the dyes. The prepared photocatalyst exhibits excellent structural stability and reusability. The toxicity of the intermediates were predicted by the ecotoxicity analysis using ECOSAR software where the end products were less toxic than parent MG and MO. The degradation pathway were elucidated to predict the possible intermediates and to confirm the complete mineralization of the compound using GC-MS analysis. The proposed study can be implemented for practical application for the degradation of organic pollutants present in the water bodies. • Ag 3 PO 4 microspheres were decorated on the flower-like BiOBr. • BiOBr/30%Ag 3 PO 4 exhibited superior photodegradation of MO and MG dyes. • BiOBr/Ag 3 PO 4 shown excellent stability and recyclable properties. • Heterojunction of semiconductor accelerated separation of photoelectron-hole pairs. [ABSTRACT FROM AUTHOR]