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In the current study, g-C3N4/Fe-MOF was synthesised and utilised for the elimination of antibiotic contaminants from wastewater. There are two steps followed for the fabrication of g-C3N4/Fe-MOF i.e. pyrolysis and solvothermal method. The proximity of g-C3N4 and Fe-MOF was confirmed by X-ray diffraction, scanning electron microscopy, ultraviolet spectroscopy, electrochemical impedance spectroscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy analysis of as-prepared samples. The developed photocatalyst was tested for tetracycline degradation. Remarkable photocatalytic activity for tetracycline under visible light irradiation is demonstrated by the g-C3N4/Fe-MOF photocatalyst. In comparison to bare g-C3N4 and Fe-MOF, the g-C3N4/Fe-MOF (G4) demonstrates significantly stronger photocatalytic activity. The best degradation efficiency of 87.12% was achieved at optimized reaction conditions with TC concenteration-25 ppm, catalyst dosage-40 mg and pH-5.5. The enhanced photocatalytic activity is because of the direct Z-scheme heterojunction formed between g-C3N4 & Fe-MOF, which allows for easier separation of photoinduced charge. The investigation also represented an analysis of the prevailing active species and potential photocatalytic mechanism. Finally, the study concludes that the optimized nanocomposite, consisting of g-C3N4/Fe-MOF, exhibited significant biocompatibility as seen by the development of barley seeds in the resultant solution after the degradation process. [ABSTRACT FROM AUTHOR]

Novel imidazopyridines hydrazine conjugates were designed and synthesized for their anti‐tubercular (anti‐TB) activity. A cytotoxicity assay was conducted with Vero cells to determine the safety profile of the most effective compounds. It was found that compound (IA3) (MIC=0.78 μM) and (IA8) (MIC=1.12 μM) were nearly 3.7 and 2.5 times more active than pyrazinamide. Based on Density functional theory (DFT), these molecules exhibited better charge transfer between molecular orbital's, which made them suitable for biological applications. Molecular docking on Mycobacterium tuberculosis InhA bound to NITD‐916 (PDB: 4R9S) revealed that compounds possessed greater binding affinity towards proteins. In addition, the most active anti‐TB compounds (IA3) and (IA8) exhibited high levels of interaction with the target protein and exceptional safety profile, suggesting they may prove to be effective leads for new drugs. [ABSTRACT FROM AUTHOR]

In this work, we report fabrication of a new Zn3V2O8/g-C3N4 Z-scheme nano-heterojunction for superior photodegradation of organo-phosphorous pesticide diazinon under visible light irradiation. The crystal structure, morphology, elemental composition, photo-electrochemical response and band structure of nano-photo-catalysts were investigated using various analytical techniques. The as-synthesized photocatalyst with best optimized ratio Zn3V2O8/40 wt% g-C3N4 (ZC-40) composites led to 95.2% diazinon (DZN) degradation in 60 min exposure and maintaining high structural stability after multiple reuse cycles (10 mg L−1 initial DZN concentration, pH = 6, catalyst dosage 0.35 g L−1 and visible light intensity 180 mW cm−2). Moreover, the experiments were performed under various reaction conditions as pH conditions, co-existing electrolytes, humic acid, tap water, river water and natural solar light. The improved photocatalytic activity of the heterojunction was ascribed to the synergistic effect of Z-scheme mechanism, high visible light absorption, oxygen vacancies, charge separation and metallic redox mediator. The reduced recombination and high charge transfer capacity was confirmed by electrochemical impedance spectroscopy and photoluminescence. The Z-scheme transfer between Zn3V2O8 and g-C3N4 boosted by V5+/V3+ metallic redox mediator retains the strong redox capacity, and diminishes the recombination. LC–MS results confirm the degradation intermediates and a detailed degradation mechanism were also predicted. Superoxide radicals (●O2–) and hydroxyl radicals (HO●) were found as major oxidative species involved in the photocatalytic degradation. The ZC-40 photocatalyst exhibited high degradation of other pesticides as malathion (90.1%), glyphosate (85.4%) and chlorpyrifos (97.4%) in water system under visible light. This work provides new approaches in designing new photocatalytic heterojunctions with high efficiency and structural robustness for utilizing visible light and efficient water treatment based on advanced oxidation technology. [ABSTRACT FROM AUTHOR]

[Display omitted] • MIL-88B(Fe)/Cu 7 S 4 S-scheme heterojunctions with S-vacancies have been developed. • MIL-88B(Fe)/Cu 7 S 4 exhibit superior photocatalytic activity toward tetracycline degradation. • The heterojunction provides rapid charge transfer and diminished recombination. • S-scheme mechanism was verified by in situ XPS, UPS and energy band structure. In order to meliorate the photocatalytic performance of materials, semiconductor heterojunction construction and engineering of vacancies/defects has been a successful strategy for advanced wastewater treatment. Herein, a sulfur vacancies rich S-scheme heterojunction was constructed by incorporating MIL-88B(Fe) and Cu 7 S 4 was constructed by in-situ hydrothermal method. The optimized MIL-88B(Fe)(20 wt%)/Cu 7 S 4 (20MCS) heterojunction exhibited superior photocatalytic activity with 94.3 % TC (20 mg L−1) removal within 90 min. The S-scheme heterojunction facilitates efficient charge carriers' separation, interfacial charge transfer facilitated by sulfur vacancies with high photo-redox capability as determined by EIS, TPCR band analysis and PL experiments. The in-situ XPS findings and UPS (work function determination) were used as direct experimental evidence for the S-scheme route and the existence of sulfur defects was confirmed by electron paramagnetic resonance (EPR). The prepared heterojunction photocatalyst demonstrates excellent efficiency, stability, and adaptability to practical environmental conditions as tested in real water samples. The scavenging and ESR experiments disclosed that O 2 – and OH radicals were generated. The mechanism for TC degradation by 20MCS was also proposed based on analysis of degradation intermediates. This novel hybrid S-scheme heterojunction photocatalyst system is quite promising for high performance environmental remediation exhibiting both stability and remarkable activity. [ABSTRACT FROM AUTHOR]

The reasonable designing, interfacial tuning and construction of S-scheme heterostructures offering high performance water pollutants treatment and energy production still remains challenging. Following the structure, band structure and interface function perspective, we prepared Fe 7 S 8 /CuIn 5 S 8 heterostructures photocatalysts with sulfur vacancies for superior norfloxacin (NOR) degradation and hydrogen production under visible light. In particular, for optimal 30FS/CIS (30%Fe 7 S 8 /CuIn 5 S 8), the H 2 evolution was up to 35.6 mmol g−1 h−1 which was 11.5 times than pristine Fe 7 S 8 with TEOA as sacrificial agent. The heterojunction could also show 98.7% degradation of NOR in 90 min under visible light. Interestingly, using NOR pollutant as sacrificial agent under synergistic conditions, 22.7 mmol g−1 h−1 H 2 evolution and 98.9% degradation of NOR (in 45 min) was achieved. The significantly boosted photocatalytic pollutant degradation and hydrogen generation performance over Fe 7 S 8 /CuIn 5 S 8 hybrids is ascribed to the efficient S-scheme charge transfer and active sites provided by sulfur vacancies (V s). The deep electron transfer mechanism and the charge transfer efficiency were supported by in-situ XPS, UPS, electrochemical experiments and photoluminescence. Experimental results including scavenging tests and ESR findings provided the direct evidence of photogenerated holes and ●OH radicals for pollutant degradation and electrons in hydrogen generation. This work contributes to effective designing and developing high-activity visible light/solar light assisted heterojunction photocatalysts for realizing superior clean energy generation and pollutant degradation. [Display omitted] • Novel S-scheme Fe 7 S 8 /CuIn 5 S 8 heterostructures successfully constructed. • Synchronous norfloxacin degradation and hydrogen evolution are realized. • The sulfur vacancies promote separation and light absorption. • The photogenerated holes/●OH and electrons are utilized for pollutant degradation and H 2 production. • The photocatalytic mechanism of H 2 evolution and NOR degradation were proposed. [ABSTRACT FROM AUTHOR]

In the present study, Ag2O–Al2O3–ZrO2 based trimetallic oxide nanocatalyst was designed using simple microwave assisted reduction method. It was characterized using various techniques such as Fourier transform-infrared (FT-IR), X-ray diffractometer (XRD), electron microscopy [scanning electron microscope (SEM), transmission electron microscope (TEM)] and X-ray photoelectron spectroscope (XPS). It was utilized for the degradation of nicosulfuron herbicide and the influence of microwave (MW) and UV radiations on the degradation rate was also studied. Maximum of 78% degradation was obtained within 50 min. Scavenging studies showed the major involvement of ·OH and ·O2− radicals in the degradation process. Possible heterostructures (traditional and Z-scheme) with their possible charge transfer were also studied. Nyquist plots and photoluminescence (PL) analysis showed the high charge transfer and lowered recombination in Ag2O–Al2O3–ZrO2. Possible degradation mechanism was also developed using LC–MS. Reusability studies were carried out for consecutive 5 cycles and results indicated the appreciable photocatalytic ability after every repeated cycles. [ABSTRACT FROM AUTHOR]

A binary S-scheme heterojunction photocatalyst, ZIF-67/Ag 3 VO 4 (ZAV), was successfully synthesized using a hydrothermal technique. The optimal ZAV-30 (ZIF-67/30 wt%Ag 3 VO 4) demonstrated excellent performance by degrading 98.5% of Venlafaxine (VEN) within 60 min under visible light. Extensive investigations were carried out regarding the crystal structure, morphology, composition, specific surface area, optical characteristics and electrochemical impedance. The ZAV-30 heterojunction photocatalyst outperformed bare ZIF-67 and Ag 3 VO 4 photocatalysts, primarily due to enhanced photon absorption and improved charge carriers' separation via S-scheme transfer, redox capability and high charge transfer capacity supported by electrochemical experiments and photoluminescence. The S-scheme transfer was validated by in-situ XPS measurements after light exposure. Scavenger experiments indicated that both •OH and •O 2 − played crucial roles as active species in the photocatalytic process. Mass spectrometry (MS) analysis of intermediates facilitated the proposal of a probable photocatalytic degradation pathway for VEN. The photoactivity of the heterojunction was influenced by a range of factors including the pH of the VEN solution, initial VEN concentration, ZAV photocatalyst dosage, and ion effects. Interestingly the ZAV-30 heterojunction exhibited superior performance in lake water, tap water and river water too. Importantly, the ZAV-30 heterojunction exhibited excellent stability and reusability, making it a promising photocatalyst. [Display omitted] • ZIF-67/Ag 3 VO 4 S-scheme heterojunction synthesized by hydrothermal technique. • ZAV-30 demonstrated 98.5% degradation of Venlafaxine within 60 min under visible light. • The S-scheme transfer accelerates charge transfer, separation and strong redox capability. • •OH and •O 2 − as main active species for photocatalytic degradation • High mineralization, reusability and durability. [ABSTRACT FROM AUTHOR]

• Metallic Ag mediated Ag 2 CrO 4 /BiFeO 3 junction on RGO matrix. • Wide spectrum response– High performance in UV, Vis, NIR and Solar light. • Triggering effect of Metallic Ag and RGO-electron mediation and facilitation. • Selective Production of CH 4 from CO 2 without any co-catalyst. • High performance photo-reduction of BrO 3 − and degradation of ciprofloxacin. Designing highly optical active photocatalytic heterojunctions with multi-pronged capabilities for environmental applications is still a challenge. In this work the photocatalytic potential of Ag 2 CrO 4 /Ag/BiFeO 3 @RGO was systematically tested via photo-reduction of BrO 3 −, degradation of Ciprofloxacin (CIF) and photo-reduction of CO 2 under broad light spectrum. Among various samples ABR-8 exhibits 99.6% BrO 3 − photoreduction and 96.3% CIF photo-oxidation in 90 min (nearly 96% in 60 min). ABR-11 (with 11 wt% RGO) selectively generates 180 μmol g−1 of CH 4 in 8 h under visible light (260 μmol g−1 under alkali activation) which is approximately 60 times than bare BiFeO 3. The excellent performance of ABR series is attributed to successful formation of Z-scheme which assists in efficient charge transfer, reduced recombination and wide spectrum response. In addition the electron donation-mediation of plasmonic Ag0 and adsorption-electron mediation of reduced graphene oxide has a triggering effect on reductive and oxidative capabilities. The band structure analysis, scavenging experiments and electron spin resonance studies make it possible to predict a suitable mechanism for bromate reduction, CIF degradation and CH 4 generation. Electron assisted BrO 3 − reduction, •OH and •O 2 − radicals powered CIF degradation by Z-scheme mechanism and multi-electron single step proton-coupled mechanism for highly selective CH 4 production were predicted. The best performing photocatalyst retain over 95% of performance over five consecutive runs. Suitable optimisations lead to higher performance from BiFeO 3 which bears many shortcomings via interfacial junction with Ag 2 CrO 4 with triggering effect from metallic Ag and RGO. Intelligently designed junctions can thus show strong photo-oxidative and reductive capabilities with further scope of fine tuning. Hence this developed heterojunction can be sustainably utilized for multi-pollutant removal and energy/fuel production under broad spectrum of light. [ABSTRACT FROM AUTHOR]

Currently available point-of-care tests for Bladder Cancer (BC) are qualitative and prone to high false positives, thus preventing them from replacing clinical cystoscopy as reliable stand-alone diagnostics. In this study, we have targeted this unmet need by developing a label-free electrochemical impedimetric immunosensor for detection of APO-A1, a major high-density lipoprotein that is overexpressed in the urine of early-stage bladder cancer patients. The immunosensor utilizes a novel multifunctional 3D nanocomposite coating consisting of a porous bovine serum albumin (BSA) matrix embedded with a network of highly conductive and biocompatible gold coated silver nanowires (Au@AgNWs). The main components of this nanocomposite coating and their specific functions include: (i) A 3D porous BSA matrix to enable oriented antibody conjugation and prevent non-specific protein adsorption while allowing diffusion of analyte with minimal hindrance as compared to traditional antifouling coatings (ii) Embedded Au@AgNWs that enhance biocompatibility and improve charge transfer to the underlying electrode. The nanocomposite coating demonstrated minimal decrease in electrochemical performance even after 1-month of incubation in 1% BSA, human serum and human urine. Furthermore, the low-cost and disposable screen-printed electrochemical immunosensor exhibited excellent feasibility for sensitive and specific APO-A1 detection in the clinically relevant sensing range of 100 pg/mL to 250 ng/mL with high reproducibility (n = 5, RSD=2.2%) and an impressive LOD of 22 pg/mL. These results highlight the potential of the proposed immunosensor to enable reliable early diagnosis of bladder cancer at the point-of-care and serve as a viable alternative to cystoscopy. [Display omitted] • Ultra-long AgNWs with epitaxially grown uniform Au coating (Au@AgNWs). • Multifunctional 3D nanocomposite for antifouling, charge transfer and biorecognition. • Superior antifouling capabilities after extended incubation in complex fluids. • Disposable electrochemical immunosensor for sensitive and specific APO-A1 detection. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fundamentals of S-scheme and dual S-scheme have been discussed. • Types of heterojunctions are elaborated with mechanism comparisons. • Recent developments in synthetic methods and different morphology of S-scheme and dual S- schemes. • S-scheme and dual S-scheme for photocatalytic environmental remediation and energy production. • Bottlenecks, conclusion and future prospects discussed. Discovering alternative materials and technologies that provide the meaningful potential to environmental and energy-related challenges in critical to the long-term viability of industrial activity and the evolution of society. Photocatalysts are undeniably important, and scientists are working hard to improve their photocatalytic performance. The high recombination rates of photogenerated electron-hole pairs as well as poor redox capability are addressed via heterojunction modification. In this direction, oxidation type and reduction type photocatalysts based S-scheme heterojunctions are highly promising owing to highly diminished recombination facilitated by internal electric field. This review has focused on the shift from Z-scheme to new revolutionary S-scheme based photocatalytic materials with high performance applications in the field of energy and environment. It can be concluded that controllable built-in electric field intensity and stable interfacial carrier transport process make S-scheme heterostrctures ideal. However their application is mainly limited to powder photocatalysts, don't apply to photo-chemistry and solar cells with external circuit, reaction thermodynamics and dynamics management in S-scheme photocatalysts is not adequate. To some extent, dual S-schemes address to these limitations and further research is to be carried out to fight the bottlenecks. Several perspectives on the future of S-scheme and dual S-scheme heterostructure were also provided based on rigorous review of the reported results. A discussion on the previously reported different types of heterojunctions and S-schemes is presented in this review along with plausible charge transfer mechanisms. The synthetic routes to S-scheme heterojunctions are also provided along with modifications and combinations. The current designing and perspective applications in numerous pollutant degradation, hydrogen production and CO 2 conversion is selectively highlighted. The transition of mechanism elucidation from Z-scheme to S-scheme has been discussed with suitable case studies. However, S-scheme heterojunctions designing and fabrication is still new commercially and so present readiness and bottlenecks have been discussed. Hence it is quite imperative for a future roadmap to be laid to design and develop economically viable high performance S-scheme heterojunctions. [ABSTRACT FROM AUTHOR]

In the present study, we have successfully formulated a dual heterojunction of g-C 3 N 4 /BiOCl@MXene-Ti 3 C 2 (GCBM) which was found to be highly active in the visible region. GCBM was found to be highly efficient for the degradation of an antibiotic, tetracycline (TC) as compared to the individual constituting units; g-C 3 N 4 and BiOCl. Maximum of 97% TC degradation rate was obtained within 90 min of visible light irradiation for initial concentration of 10 mg/L of TC. Optical analysis exhibited that the synthesized heterojunction showed high absorption in the complete spectrum. The reactive species specified by the scavenger study showed the major involvement of • O 2 − and • OH radicals. The charge transfer mechanism showed that 2 schemes were majorly involvement in which Z-scheme was formed between g-C 3 N 4 and BiOCl and Schottky junction was formed between g-C 3 N 4 and Mxene-Ti 3 C 2. The formation of Schottky junction helped in inhibiting the back transfer of photogenerated charges and thus, helped in reducing the recombination rate. The synthesized photocatalyst was found to be highly reusable and was studied for consecutive 5 cycles that generalized the high proficiency even after repetitive cycles. [Display omitted] • Visible-light active heterojunction g-C 3 N 4 /BiOCl@MXene-Ti 3 C 2 GCBM) was designed. • Z-scheme and Schottky junction was used for explaining the charge transfer. • MXene-Ti 3 C 2 reduced the chances of back reactions. • O 2 − and OH radicals were found to be the major reactive species. [ABSTRACT FROM AUTHOR]

Significant ecosystem damage and severe environmental issues have surfaced due to unplanned exploitation of resources and industrial expansion. The water bodies are continuously polluted by numerous organic dyes released from industrial effluents. In this work, we report construction of new g-C 3 N 5 /Bi 24 O 31 Br 10 S-scheme heterojunction for UV–visible light driven superior organic dye degradation. The integrated heterojunction with high interfacial charge transfer exhibited excellent 99.08% (∼100%) within 60 min exposure which is manifolds higher than bare g-C 3 N 5 and Bi 24 O 31 Br 10. The mechanistic investigations showed that the key active radicals in photocatalytic CV degradation are the •O 2 - and h+. Building an S-scheme model with favourable energy band structure encourages efficient separation of charges while maintaining the inherent redox capacity of the g-C 3 N 5 /Bi 24 O 31 Br 10 catalyst, which is highly beneficial for superior photocatalytic performance. This work offers a fresh viewpoint for creating organic-inorganic hybrid new S-scheme heterojunctions for high performance photocatalytic waste-water treatment. • High efficiency 2D–2D g-C 3 N 5 /Bi 24 O 31 Br 10 S-scheme heterojunction was designed. • Catalyst exhibit excellent degradation efficiency of 99.08% for CV removal. • PL suggests the efficient charge separation of the carriers. • ·O 2 - and h+ are responsible for CV degradation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Complete assignments of vibrational modes have been made using DFT/B3LYP method. [•] NBO is done for interpretation of hyperconjugative interactions and charge transfer. [•] The UV–vis spectrum examined in DMF solvent and calculated using TD-DFT approach. [•] 1H chemical shifts are calculated by GIAO method and compared with experimental ones. [•] First hyperpolarizability was computed to confirm the suitability for NLO application. [Copyright &y& Elsevier]

Designing and fabrication of smart hybrid multifunctional materials for energy/fuel production and environmental detoxification is indeed of great significance for sustainable development. Herein, we synthesized a new well-structured S-scheme heterostructure Fe@TiO 2 /Boron Carbon nitride (FT/BCN) with high performance tetracycline degradation and selective CO 2 photo-reduction to CH 4. Under visible light irradiation, 96.3% tetracycline was degraded in 60 min using best performing FT30/BCN sample with a high 83.2% total organic carbon removal in 2 h. The tetracycline degradation rate for FT30/BCN composite catalyst was ∼7 times than bare boron carbon nitride (BCN). The impact of reaction parameters as pH, presence of interfering electrolytes, light source and water matrix was also investigated. The FT30/BCN photocatalyst shows dramatic improvement in CO 2 photoreduction as exhibited in 24.7 μmol g−1 h−1 CH 4 and 2.4 μmol g−1 h−1 CO evolutions with optimal 91.1% CH 4 selectivity. Pure BCN shows a poor 39.1% selectivity. Further, effect of alkali activation, CO 2 /H 2 O feed ratio, reducing agent and light source onto CH 4 production and selectivity was also investigated. The CH 4 evolution and selectivity was improved because of enhanced visible light absorption, high adsorption potential, charge carrier separation and high reducing power of photogenerated electrons induced by an effective S-scheme heterojunction between Fe@TiO 2 and boron carbon nitride. An S-scheme (step-scheme) charge transfer mechanism is here operative both during tetracycline removal and CO 2 reduction. The drug degradation route and photocatalytic mechanism for antibiotic removal and CO 2 reduction was also predicted. [Display omitted] • Fe@TiO 2 /Boron carbon nitride heterojunction fabricated by hydrothermal route. • High performance antibiotic removal under visible and solar light. • Photo-induced CO 2 reduction with H 2 O for highly selective CH 4 production. • Efficient S-scheme charge transfer mechanism observed between Fe@TiO 2 and BCN. • Antibiotic degradation and selective CH 4 production detailed mechanism elucidated. [ABSTRACT FROM AUTHOR]

[Display omitted] • The present work suggests that inside C 36 , O-O covalent bond can be formed between H 2 O molecule. • The Se-Se covalent bond can be formed between H 2 Se molecule inside C 60 fullerene. • Charge transfer between dimer and fullerene plays key role in covalent bonding between guest moiety. In the present investigation, we have studied the effect of confinement on the nature of the bonding in H 2 O dimer as well as in H 2 Se dimer. The present work suggests that inside C 36 , O-O covalent bond can be formed between H 2 O molecules, whereas Se-Se covalent bond can be formed between H 2 Se molecules inside C 60 fullerene. Further, this result was supported by the atoms in molecules (AIM) and natural bonding orbital (NBO) analysis, which indicates the formation of covalent bonds in (H 2 O) 2 as well as in (H 2 Se) 2 inside confinement. It was also found that the covalent bonding is facilitated by the charge transfer between dimer and fullerene. [ABSTRACT FROM AUTHOR]

• Novel Fe 3 O 4 -BiVO 4 /Cr 2 V 4 O 13 heterojunction fabricated. • High charge separation and interfacial charge transfer. • High performance removal of fluoxetine under visible light. • ●OH as active species -high potential band protection. • Fe 3 O 4 and Cr redox mediated Z-scheme mechanism. Hybrid heterojunction photocatalysts dramatically improve the pharmaceutical wastewater treatment potential. In this work, we report construction of novel Fe 3 O 4 -BiVO 4 /Cr 2 V 4 O 13 (FBC) with high interfacial transfer for visible and solar photo-degradation of fluoxetine (FX). Within 60 min of visible exposure, FBC removes 99.2% of FX and rate is ~ 8 times BiVO 4. The strongly coupled heterojunction leads high charge separation, interfacial charge transfer which attributes to the exceptional performance. Scavenging experiments and electron spin Resonance (ESR) probe suggest ●OH and ●O 2 – radicals as dominant species. The band structure and other experiments reveal a Z-scheme effective charge transfer is in action mediated by Fe 3 O 4. [ABSTRACT FROM AUTHOR]

In this work, a carbon quantum dots (CQDs) decorated dual Z-scheme CeO 2 /g-C 3 N 4 /V 2 O 5 heterojunction (CCGV) was rationally synthesized by simple hydrothermal method. The crystal structure, morphology, and optical properties of the photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflectance spectroscopy. CCGV catalyst shows high visible absorption, including near infra-red region and solar light via two-channel charge transfer (dual Z-scheme), reduced recombination, and up-conversion effect of CQDs. The heterojunction was used for visible assisted photo-reduction of carcinogenic hexavalent chromium ions (Cr(VI)) with a 99% reduction in 100 min without any sacrificial agent or hole scavenger. The reaction becomes more rapid with tartaric acid as a scavenger with a complete reduction in just 30 min under visible light. Photogenerated electrons are the dominant active species, followed by ●O 2 −, as revealed by the scavenging experiments. The use of sacrificial agents and scavengers suggests that photogenerated electrons were the dominant active species followed by ●O 2 − radicals. The electrochemical impedance spectroscopy and photoluminescence results confirm highly reduced recombination, high charge separation, and charge transfer capacity in the dual Z-scheme heterojunction. The conduction band edges of CeO 2 and V 2 O 5 (which are protected by the dual charge transfer) have an appropriate potential for the rapid reduction of hexavalent chromium. The XPS scan of the catalyst after separation shows the presence of Cr in the +3 oxidation state, suggesting complete photo-reduction. This study is promising for developing wide spectrum active simple heterojunction photocatalysts for pollutant removal with high efficiency. Image 1 • Dual Z-scheme CQDs @ CeO 2 /g-C 3 N 4 /V 2 O 5 heterojunction (CCGV) was successfully prepared. • CCGV junction shows efficient photoreduction of carcinogenic hexavalent chromium. • Visible, NIR and solar activity with high visible capture. • Mechanistic approach-Scavenging and Sacrificial agents. • Comparison between conventional and dual Z-scheme-high potential bands. [ABSTRACT FROM AUTHOR]

• Carbon dots (CDs) were synthesized from curry leaves by the hydrothermal method for selective and sensitive detection of Cd2+ ions. • The fluorescence quenching of CDs was due to ligand-to-metal charge transfer (LMCT). • This sensing mechanism was followed by dynamic quenching and characterized by UV-visible spectra and life-time decay analysis. • These CDs were highly selective towards Cd2+ ions sensing with a limit of detection is 0.29 nM. Cadmium ion is the most toxic metal ion among all the hazardous metals; so, its detection is a crucial area for research and diagnosis. In this article, we have synthesized carbon dots (CDs) from natural source [ Murraya koenigii (Curry leaves) leaves] by the hydrothermal method for selective and sensitive detection of Cd2+ ions. The fluorescence quenching of CDs was due to ligand-metal charge transfer (LMCT). The synthesized CDs can donate electrons pair to the excited state vacant d-orbitals of the Cd2+ ions and form a chelate and diminishes the fluorescence intensity of the CDs. The synthesized CDs were characterized by Photoluminescence, UV-visible spectra, zeta potential, XRD, FTIR, HR-TEM, XPS, DLS, and life-time decay analysis. The CDs was highly selective towards Cd2+ ions sensing with broad linear range (0.01-8 μM) and limit of detection 0.29 nM. More importantly, this synthesized CDs successfully detect the Cd2+ ions in real water samples, and also shows high selectivity to Cd2+ ions even in the occurrence of other interfering metal ions. [ABSTRACT FROM AUTHOR]

Rationally fabricated Z -scheme hetero-junctions with intimate interfacial contact have proven to accelerate the photocatalytic degradation of noxious pollutants by effectively suppressing the recombination and promoting charges transfer rate. Herein, we report fabrication of reduced graphene oxide (RGO) modified LaTiO 2 N/Bi 2 S 3 heterojunction photocatalyst by sovothermal route. The microstructure analysis, structure determination, electronic and optical analysis of as prepared photocatalysts was done by using multiple techniques. The Z -scheme LaTiO 2 N/Bi 2 S 3 @RGO (LBR) photocatalyst shows remarkable performance for photo-degradation of tetracycline (TC) under visible light. 96.4% TC was eliminated within 90 min under visible light with ~100% removal in 60 min under full spectrum irradiation. In addition the heterojunction shows 80.2% TC removal under natural sunlight irradiation. The TC degradation with LBR heterojunction is ~9 times faster than bare Bi 2 S 3. The Z -scheme transfer follows the route as Bi 2 S 3 → RGO → LaTiO 2 N and provides a swift path for movement of electrons from CB of LaTiO 2 N to VB of Bi 2 S 3. The possible degradation route of TC has also been proposed based on quenching experiments and identification of degradation intermediates by Liquid chromatography-mass spectrometry (LC-MS). The quenching experiments reveal that O 2 – radicals are the main active species involved followed by OH radicals which has been explained by thermodynamic feasibility of their production from the junction arrangement. The mechanism has been explained by Z -scheme transfer by comparing to the conventional type-II junction. The enhancement in photocatalytic activity is primarily attributed to Z-scheme charge transfer between LaTiO 2 N and Bi 2 S 3 facilitated by reduced graphene oxide sheet via strong interfacial contact maintaining high potential for redox conversions. The recycling experiments reveal the stability and reusability of the LBR hybrid photocatalyst with ability to perform under sunlight. The novel nitrides-phosphide based junction with improved properties for visible and solar photocatalytic activity provides future prospects in forming superior hetero-structures for environmental remediation. Unlabelled Image • LaTiO 2 N/Bi 2 S 3 @RGO heterojunction photocatalyst fabrication by simple solvothermal route. • High performance degradation of tetracycline-visible, full spectrum and sunlight • Interfacial charge transfer capacity-internal electric field–higher spectral capture. • Z-scheme and RGO lead to high charge separation, high redox capability, stability. • Thermodynamic feasibility and experimental findings suggest Z-scheme over conventional type-II transfer. [ABSTRACT FROM AUTHOR]

Fabrication of highly active photocatalysts that can be utilized for water detoxification is the need of time. In present work, we have synthesized La/Co/Ni TNPs and graphene oxide (GO) supported La/Co/Ni trimetallic nanocomposite (La/Co/Ni@GO TNC) using simple microwave method. The potential application of TNPs and TNC has been explored for photodegradation of 2-chlorophenol (2-CP) under natural sunlight irradiations. Among the two, La/Co/Ni@GO TNC (71% in 300 min) exhibited better photocatalytic ability as compared to La/Co/Ni TNPs (57% in 300 min). The superior performance of La/Co/Ni@GO TNC is credited to the efficient charge transfer and reduced electron-hole recombination ability. The band structure analysis, scavenging experiments and terephthalic acid studies have made it possible to finalise a probable degradation mechanism for 2-CP. Unlabelled Image • La/Co/Ni TNPs and La/Co/Ni @GO TNC synthesized by microwave reduction method • Photocatalytic degradation of 2-chlorophenol undertaken • GO offered high catalytic surface area and acted as sink • Band gap of 2.42 eV in the semiconductor region shown by La/Co/Ni @GO TNC • 71% degradation rate acquired in 300 min [ABSTRACT FROM AUTHOR]

A correction to the article "Mechanism of Charge Transport in Poly(2,5-dimethoxyaniline)" that was published online on January 18, 2011 is presented.

[Display omitted] • Ni 1-x Zn x Fe 2 O 4 inverse spinel ferrite photocatalyst prepared by combustion route. • Dopant determined CB shifting-higher thermodynamic O 2 − generation potential. • Superior photo-degradation of levofloxacin under visible and solar light. • Higher charge separation and transfer capacity-metal redox. • Suitable degradation pathway for levofloxacin proposed. Spinel ferrites with a compatible electronic band structure are always excellent candidates for photo-catalytic environmental detoxification employing visible light and solar energy. However, the potential is not harnessed to its fullest owing to unnerving charge carrier recombination. In this work, we report the synthesis of Ni 1-x Zn x Fe 2 O 4 (x = 0, 0.1, 0.3, & 0.5) mixed spinel ferrites via combustion route. As prepared samples were characterized for phase identification using X-ray diffraction (XRD) and Reitveld refined pattern confirms the formation of single phased cubic structure with a nano-metric crystallite size. The homogeneous distribution of grains and particles is evidenced by shape and size morphological studies. Raman spectroscopy reveals the presence of motion of oxygen in tetrahedral and octahedral voids. The dc electrical resistivity measured using the two probe method is found to be in the range of 107 to 108 Ω-cm. The optical band gap measured for all photo-catalysts resides at 2.11–2.53 eV. The ferrite photocatalyst exhibits high visible absorption, superior charge transfer capacity, and highly suppressed recombination as suggested by electrochemical impedance spectroscopy and photoluminescence results. The change in band structure with variable Zn content was monitored by shifting of conduction and valence bands. The photo-catalyst Ni 0.7 Zn 0.3 Fe 2 O 4 (N2) exhibited 96.8% levofloxacin (LEV) degradation in 90 min of visible light exposure. The effect of parameters such as pH, catalyst dosage, electrolytes and water matrix was analysed in detail. The photo-catalytic degradation rate was enhanced in the presence of persulfate and H 2 O 2. Furthermore, the high magnetic character of the catalysts aids in their retrieval post utilization in catalysis. In terms of band structure analysis, role of dopants, metal redox, and scavenging studies, a suitable photo-catalytic process was proposed. Degradation intermediates discovered by liquid chromatography–mass spectrometry analysis were also recommended as a pathway of degradation. These findings open up exciting possibilities for developing novel solar active photo-catalytic systems based on spinel ferrites for efficient environmental cleanup. [ABSTRACT FROM AUTHOR]

The capacitance dispersion in La and Mg co-substituted BiFeO3 thin film has been studied at different stages of polarization switching. A negative capacitance (NC) behavior is observed in the sample that is fatigued above 109 switching cycles. The origin of the NC is investigated through analyzing relaxation processes and charge transport kinetics by admittance spectroscopy. An activation energy of ∼0.6 eV and a zero field mobility μ0=5.33±0.02×10-13m2/Vs are thus obtained. A physical mechanism is proposed to explain this behavior. It involves a redistribution of oxygen vacancies, which are trapped at the film/electrode interface during the fatigue process. [ABSTRACT FROM AUTHOR]

• Complete vibrational assignments are given on the basis of PED. • NBO explains the charge transfer interactions within the molecule. • 1H NMR chemical shifts of DCBC were studied. • HOMO–LUMO energies were used to calculate global reactivity parameters. • Electronic and vibrational contributions to α, β and γ were investigated. This work presents the spectroscopic analysis and nonlinear optical (NLO) behaviour of 1-(4-Bromophenyl)-3-(2,4-dichlorophenyl)‑prop-2-en-1-one (DCBC). The motivation behind choosing chalcone derivative DCBC for NLO studies is its crystallization in non-centrosymmetric structure, excellent second harmonic generation efficiency (SHG) and flexibility in structure of chalcones due to donor-acceptor groups. The compound was characterized by FT-IR, FT-Raman, UV–vis and NMR techniques. The structural and spectroscopic features of the molecule were calculated using density functional theory (DFT) employing B3LYP/6–311++ G (d,p) basis set and compared with the experimental values. The complete vibrational assignments were made on the basis of potential energy distribution (PED). The Natural Bond Orbital (NBO) analysis of DCBC has been done in order to provide the detailed insight into the nature of electronic conjugation between the bonds in this molecule. The second-order perturbation theory analysis of Fock matrix in the NBO basis of the molecule shows the strong intramolecular hyperconjugative interactions between σ (Cl3-C28) to σ*(C26-C28), n(1)(Cl3) to σ*(C26-C28) and π(C6-C8) to π*(C5-C13) resulting in large stabilization energies leading to large delocalization. A time-dependant variant of DFT (TD-DFT) is applied to calculate the electronic properties such as oscillator strengths, absorption maxima and HOMO and LUMO energies. The HOMO-LUMO energy gap is found to be 3.882 eV and is used to calculate global reactivity parameters. Isotropic chemical shifts were calculated using gauge invariant atomic orbital (GIAO) method and these matched well with the experimental results, indicating the accuracy of calculation method. Molecular Electrostatic Potential (MEP) surface has been depicted to know the chemically active regions of the molecule. The nonlinear optical properties of title molecule were addressed theoretically by the determination of two contributions, vibrational and electronic, to polarizability (α) and the first and the second order hyperpolarizabilities (β and γ). The electronic first and second order hyperpolarizabilities of DCBC determined by Finite Field approach method are found to be 17.805 × 10−30 and 6.0 × 10−41 e.s.u. respectively. These values are comparable to other chalcones and organic NLO materials which indicate that the studied molecule is responsive to nonlinear optical (NLO) effect and has enhanced applicability in the development of nonlinear optical devices. [ABSTRACT FROM AUTHOR]