Separation Efficiency Of Electron-hole Pairs Research Articles

Dual Polarization Strategy for Boosting Electron-Hole Separation toward Overall Water Splitting within Ferroelectric β-AIBIIIO2 (BIII = P3+, As3+, Sb3+, and Bi3+ for Lone Pairs).

Ferroelectric materials, leveraging an inherent built-in electric field, are excellent in suppressing electron-hole recombination. However, the reliance solely on bulk polarization remains insufficient in enhancing carriers' separation and migration, limiting their practical application in photocatalytic overall water splitting (POWS). To address this, we incorporated cations with ns2 lone pairs (P3+, As3+, Sb3+, and Bi3+) into ferroelectric semiconductors, successfully constructing 44 β-AIBIIIO2 photocatalysts with dual polarization. Through rigorous first-principles calculations and screenings for stability, band characteristics, and polarization, we identified four promising candidates: β-LiSbO2, β-NaSbO2, β-LiBiO2, and β-TlBiO2. Within these materials, lone pairs induce local polarization in the xy-plane. Additionally, out of the plane, there is robust bulk polarization along the z-direction. This synergistic effect of the combined local and bulk polarization significantly improves the separation efficiency of electron-hole pairs. Explicitly, the electron mobility of the four candidates ranges from 105 to 106 cm2 s-1 V-1, while the hole mobility also increases significantly compared to single-phase polarized materials, up to 106 cm2 s-1 V-1. Notably, β-TlBiO2 is predicted to achieve a solar-to-hydrogen (STH) efficiency of 17.2%. This study not only offers insights for water-splitting catalyst screening but also pioneers a path for electron-hole separation through the dual polarization strategy.

Fabrication of porous biochar supported Bi2MoO6 photocatalyst for efficient degradation of ciprofloxacin in seawater under visible light irradiation: Mechanistic investigation and intermediates analysis

Efficient separation of photocarriers is a critical approach for advancing high-performance photocatalyst systems to effectively remove environmental contaminants. In this investigation, a hydrothermal technique was employed to synthesize composites of Bi2MoO6 and porous biochar derived from banana peels (BPB). The samples underwent various characterization methods to assess their composition, morphology, and photoelectrochemical properties. The BPB/Bi2MoO6 composite exhibited a synergistic adsorption and photocatalytic impact in eliminating the antibiotic ciprofloxacin (CIP) from pure water and seawater. The optimized BPB/Bi2MoO6 sample displayed a significant degradation efficiency of 98.7 % for CIP after 90 min of visible-light exposure in pure water. In artificial seawater, the degradation efficiency for CIP remained high at 93.6 %, which was 12.2 times greater than that of pure Bi2MoO6. The study also explored the impact of various factors such as catalyst dosage, solution pH, and pollutant concentration on the photocatalytic performance of BPB/Bi2MoO6. Moreover, the catalyst exhibited enhanced efficiency in the adsorption-photocatalytic degradation of CIP within a continuous flow reaction system. The enhanced photocatalytic performance was attributed to the composite's exceptional adsorption capacity, enhanced response to visible light, and efficient separation of photoinduced electron-hole pairs. Furthermore, the BPB/Bi2MoO6 photocatalyst displayed good stability and recyclability over five consecutive photodegradation cycles. Radical trapping and electron spin resonance (ESR) experiments verified that the degradation of CIP was mainly driven by •OH and h+ radicals. A thorough investigation employing density functional theory (DFT), radical trapping and ESR tests, and liquid chromatography mass spectrometry (LC-MS) was conducted to elucidate the degradation mechanism and pathways. Furthermore, toxicity assessment software was utilized to illustrate the progressive reduction in toxicity of the intermediate products. In conclusion, this study provides valuable insights into the role of biochar in enhancing the photocatalytic degradation of pollutants and offers guidance for the future development of environmentally friendly photocatalysts.

Preparation and photocatalytic properties of Bi2WO6/Ag/ZnO composite nanomaterials

AbstractPhotocatalysis leverages light energy for chemical transformations, presenting an environmentally friendly approach to mitigating pollution. We have developed Bi2WO6/Ag/ZnO composite nanomaterials that demonstrate enhanced photocatalytic efficiency. These nanomaterials have been characterized through advanced techniques such as x‐ray diffraction and x‐ray photoelectron spectroscopy. A key challenge in photocatalysis is the effective separation of electron–hole pairs, and our Bi2WO6/Ag/ZnO composites achieve an impressive degradation rate of 96.93% for methyl orange. This result notably exceeds previous performance standards and highlights the crucial role of Ag in broadening the light response spectrum of zinc oxide (ZnO), and the addition of Bi2WO6 in amplifying the electron–hole pair separation efficiency within these composite nanomaterials. These findings underscore the significant potential of Bi2WO6/Ag/ZnO composites in environmental detoxification and establish a new benchmark in photocatalytic material performance. The advancement of such nanomaterials could be transformative for environmental remediation strategies, offering efficient, sustainable, and cost‐effective solutions to ecological challenges. This study underscores the pivotal role of materials science in advancing environmental sustainability.

Covalent copper-organic frameworks with light-activable catalytic centers as smart artificial enzymes for highly sensitive and wide-range biocatalytic diagnosis

As a popular sensing method, colorimetric biosensing has the advantages of convenient operation, low cost, fast response, and easy readout. However, due to the complex structure of nanomaterials, low catalytic activity, and unclear catalytic mechanisms, constructing efficient, stable, and specific artificial biocatalysts for colorimetric biosensing is still a challenge. In this study, to propose a new colorimetric biosensing system, we synthesize three different types of copper cyclic trinuclear unit-based 2D copper-organic frameworks (CuOFs) with covalent structures and light-activable catalytic centers to serve as smart artificial enzymes for highly sensitive and wide-range biocatalytic diagnosis. By varying the light absorption centers, CuOFs with different band structures, light absorption capacity, photoelectron transfer efficiency, and electron-hole pair separation efficiency can be obtained. Of the three covalent CuOFs, tris(4-aminophenyl)amine (Tpa)-Cu3 exhibited the widest light absorption range, the narrowest band gap, the smallest electron transfer barrier, and the best-photoinduced charge separation efficiency, which was conducive to improving the light capture ability and eventually improving the photocatalytic properties. Further tests demonstrated that Tpa-Cu3 exhibited the best peroxidase-like activity under visible light irradiation, which could effectively diagnose the glucose and common antioxidants with a wider detection range and lower detection limit than many previously reported biocatalytic materials. We expect this design will provide new insights into enzyme-like organic framework materials and unique systems for high-sensitive and wide-range colorimetric detection for future biocatalytic applications.

Microwave synthesized ternary BiOCl/BiOBr/Bi2O3 nanocomposite for enhanced degradation of organic contaminants under visible light exposure

BackgroundThis research addresses the urgent need for efficient water treatment methods to treat water pollution resulting from industrial activities and population growth. It focuses on developing semiconductor-based photo-catalysts with enhanced photocatalytic activity under visible light, aiming to contribute to pollution control and sustainable energy solutions. MethodsA novel layer-structured ternary BiOCl/BiOBr/Bi2O3 nanocomposite was successfully synthesized via a rapid, one-step microwave-assisted method. The unique layered structure of this heterojunction facilitated efficient migration and separation of photoinduced electron-hole pairs, essential for effective photocatalysis. Significant FindingsThe synthesized nanocomposite exhibited excellent photocatalytic performance, achieving complete degradation of 30 mg L−1 RhB, 98.0% efficiency for 10 mg L−1 TCH, and 83.0% efficiency for 10 mg L−1 MO. Furthermore, the photo-catalyst displayed remarkable photostability, retaining 99.7% efficiency even after seven cycles of RhB degradation. The study also revealed favorable conditions for RhB degradation, emphasizing the impact of high temperature and low pH media while demonstrating the catalyst's resilience to the presence of ions (NO3−, Cl−, SO42−, and NH4+). The study indicates that singlet oxygen (1O2) was predominant among the oxidizing species in photodegradation. This work introduces a highly efficient and stable ternary BiOCl/BiOBr/Bi2O3 nanocomposite as a promising solution for addressing water pollution issues and harnessing visible light for photocatalytic applications.

Lattice strain engineered reactive oxygen species generation of NaNbO3 ferroelectric

The generation of reactive oxygen species (ROS) using ambient mechanical energy with piezoelectric materials is emerging as a promising method for producing renewable green oxidants. However, the low piezoelectricity and limited electron-hole pair separation efficiency significantly hinder its productivity. Here, non-stoichiometric Na1-xNbO3-δ perovskites with lattice strain and ferroelectric enhancement were successfully designed to boost the piezo-catalytic activity. Significantly, hydrogen peroxide (H2O2), superoxide radicals (•O2-), and hydroxyl radicals (•OH) were powerfully generated by the Na0.95NbO2.975 piezo-catalyst through redox reaction with rates of 362.4, 69.3, and 65.0 µmol∙g-1∙h-1, respectively, and the yield of H2O2 was approximately three times higher than that of the stoichiometric NaNbO3. The elevated piezoelectricity and polarization electric field effects induced by lattice strain could promote the generation of electron-hole pairs and drive them to separate facilely. The distribution of sodium vacancies and oxygen vacancies in the crystal lattice enhanced the diffusion of carriers for fast migration to the opposite surface of the catalyst. Furthermore, the presence of Na defects enhanced the adsorption of O2 on the Na1-xNbO3-δ surface and contributed to the catalytic generation of H2O2. This work provides a novel and effective methodology for the design of high-performance piezo-catalysts with lattice-strained engineering and broadens the strategy for improved H2O2 evolution efficiency.

Protonated g-C3N4/oxygen-doped g-C3N4 S-scheme homojunction fabricated by electrostatic self-assembly for photocatalytic hydrogen evolution and tetracycline hydrochloride degradation

S-scheme photocatalytic systems with high redox ability and separation efficiency of photoexcited charge carriers supply considerable prospects for environmental optimization and sustainable energy development. However, coupling well-suited reduction and oxidation components for target reactions remains a challenge worth exploring. Herein, an efficient S-scheme system for H2 generation and tetracycline hydrochloride (TCH) photodegradation based on protonated g-C3N4 (PCN) coupling with oxygen-doped g-C3N4 (OCN) is fabricated via a facile electrostatic self-assembly strategy. Intimate interfacial interactions originating from the ultrathin nanostructure and staggered energy band arrangement for the S-scheme charge transfer pathway provide compelling advantages for the highly efficient separation of photoinduced electron-hole pairs in the as-designed PCN/OCN homojunction. The in-situ irradiated X-ray photoelectron spectroscopy (ISI-XPS) techniques and electron paramagnetic resonance (EPR) measurements are applied to confirm the successful construction and the validity of the S-scheme charge transfer pathway. The obtained PCN/OCN composites with optimal ratio achieve a decent H2 generation rate of 6184.7 μmol g−1 h−1 outpacing the single PCN by approximately 4.8-fold, and 90.5 % TCH photodegradation efficiency is also realized within 90 min. This work provides a delicate fresh round of elevation for the exploration of an effective photocatalytic system.

Enhanced photoreduction of U(VI) in solution by Ti3C2Tx/g-C3N4 composites

The enhanced transfer efficiency of electron from photocatalyst to U(VI) is crucial for U(VI) photoreduction. Herein, we developed porous 2D/2D Ti3C2Tx/g-C3N4 heterojunction structure through the pyrolysis gasification of urea during direct calculation of Ti3C2 nanosheet and urea. Ti3C2Tx/g-C3N4 hybrid displayed the exceptional photocatalytic performance, high reaction rate constant (k1 = 0.0228 min−1) and rapid removal kinetics due to high photocatalytic activity, good chemical stability and highly efficient separation of photo-generated electron-hole pairs. According to quenching experiments and ESR analysis, the superoxide (.O2-) radicals played an important role in U(VI) photoreduction by Ti3C2Tx/g-C3N4. The higher efficient migration of photo-generated electrons from g-C3N4 to Ti3C2 co-catalyst was attributed to the tight interfacial interaction of –NHx of g-C3N4 with Ti3C2 via NHx-Ti chemical bonding, which increased the photoreduction of U(VI) into U(IV) by XPS analysis. The findings are crucial for designing g-C3N4-based catalysts by manipulating electronic structure for enhanced U(VI) photoreduction.

Role of Pyramidal Low-Dimensional Semiconductors in Advancing the Field of Optoelectronics

Numerous optoelectronic devices based on low-dimensional nanostructures have been developed in recent years. Among these, pyramidal low-dimensional semiconductors (zero- and one-dimensional nanomaterials) have been favored in the field of optoelectronics. In this review, we discuss in detail the structures, preparation methods, band structures, electronic properties, and optoelectronic applications (photocatalysis, photoelectric detection, solar cells, light-emitting diodes, lasers, and optical quantum information processing) of pyramidal low-dimensional semiconductors and demonstrate their excellent photoelectric performances. More specifically, pyramidal semiconductor quantum dots (PSQDs) possess higher mobilities and longer lifetimes, which would be more suitable for photovoltaic devices requiring fast carrier transport. In addition, the linear polarization direction of exciton emission is easily controlled via the direction of magnetic field in PSQDs with C3v symmetry, so that all-optical multi-qubit gates based on electron spin as a quantum bit could be realized. Therefore, the use of PSQDs (e.g., InAs, GaN, InGaAs, and InGaN) as effective candidates for constructing optical quantum devices is examined due to the growing interest in optical quantum information processing. Pyramidal semiconductor nanorods (PSNRs) and pyramidal semiconductor nanowires (PSNWRs) also exhibit the more efficient separation of electron-hole pairs and strong light absorption effects, which are expected to be widely utilized in light-receiving devices. Finally, this review concludes with a summary of the current problems and suggestions for potential future research directions in the context of pyramidal low-dimensional semiconductors.

Enhanced photocatalytic degradation performance of cornstalk templated TiO2 towards ciprofloxacin in hospital wastewater by the synergistic effect of the (101)/(001) facets coexposed and NiO cocatalyst

In this work, a novel TiO2 photocatalyst (marked as yNiO/5 F-CSTG) was designed and synthesized through a solvothermal pathway assisted with a bio-template, which prefectly combined the strategy of crystalline facet engineering and co-catalyst. The experiment and characterization results indicated that the co-exposure of {101}/{001} facets over TiO2, surface heterojunction and NiO cocatalysts jointly promote the photocatalytic performances, which can be attributed to the high separation efficiency of electron-hole pairs. Additionally, the introduction of morphology regulator (i.e., glycerinum) induced the directional growth of TiO2，being beneficial to broaden the responsive range of visible light. Consequently, compared with pristine TiO2 and CST, the photocatalytic removal rate of 1NiO/5 F-CSTG towards CIP increased ∼24.8 and ∼2.6 times. Besides, for tap-water and hospital sewage, its photocatalytic removal rate reached 89.15 % and 56.32 %, respectively. DFT calculation showed that the F- doping into TiO2 led to the formation of impurity energy level, which contributed to the electron transfer between the co-exposure facets of {101}/{001}. This work provides certain valuable hints for the development of bio-templated photocatalysts.

Internal electric field and oxygen vacancies synergistically boost S-scheme VO/BiOCl-TiO2 heterojunction film for photocatalytic degradation of norfloxacin

Sluggish interfacial dynamics and weak redox properties make the degradation of antibiotics by photocatalysts still a great challenge. Herein, constructing S-scheme heterojunction between BiOCl and TiO2 nanorod arrays (TNA) by hydrothermal method, and the synergistic effect of oxygen vacancies (VO) and Internal Electric Field (IEF) on improving the performance of the photocatalysts was revealed by adjusting the VO. The VO modified BiOCl-TiO2 (VBiTNA) exhibited excellent photocatalytic activities for norfloxacin, achieving a degradation efficiency of up to 90.2 % in just 60 min, and the rate constant was as high as 3.67 × 10-2 min−1. In addition, it also showed great photocatalytic degradation performance of NOR in a wide pH range, complex ionized water environment and real water source. The degradation intermediates and degradation pathway of NOR were predicted with LC-MS technology and Fukui function. Combined with free radical capture, electron paramagnetic resonance, relevant electrochemical testing, and DFT calculations reveals the mechanism of the enhanced photocatalytic performance of VBiTNA. The performance enhancement can be attributed to the expansion of the light absorption range, enhanced adsorption of O2 and effective activation to generate ·O2–, while improving the separation efficiency of electron-hole pairs and maintaining a strong redox capacity. This research focusing on VO and IEF mechanisms will help to advance the rational design of high-performance defective photocatalysts.

Acid modification on ZnIn2S4 with sulfur vacancy for highly efficient photocatalytic reduction of Cr(VI)

Anion vacancies caused by acid treatment over photocatalysts have significant influences on photocatalytic processes. In this study, the ZnIn2S4 (denoted as ZIS) nanoflower samples were synthesized using a one-step hydrothermal process and then impregnated with different amounts of nitric acid solutions. The gathered samples were characterized using XRD, SEM, XPS, BET, and EPR, and their photocatalytic reduction activity of Cr(VI) was also studied. Owing to defect structures, the removal of Cr(VI) of sulfur-rich vacancies ZIS-NA-3 reached nearly 100% within 90 min under simulated solar light, which was about 3 times greater than that of the original ZIS. In summary, this study confirmed that nitric acid treatment could form a defect state on the surface of catalysts, enhancing the light absorption range and improving the electron-hole pair separation efficiency. Furthermore, the stability and recycling of the ZIS-NA-3 catalysts were evaluated. This work offered a simple surface modification technique for constructing high-activity photocatalysts so as to achieve the purpose of removal from polluted wastewater containing Cr(VI).

Narrow Bandgap Schottky Heterojunction Sonosensitizer with High Electron-Hole Separation Boosted Sonodynamic Therapy in Bladder Cancer.

Sonodynamic therapy (SDT) is applied to bladder cancer (BC) given its advantages of high depth of tissue penetration and nontoxicity due to the unique anatomical location of the bladder near the abdominal surface. However, low electron-hole separation efficiency and wide bandgap of sonosensitizers limit the effectiveness of SDT. This study aims to develop a TiO2-Ru-PEG Schottky heterojunction sonosensitizer with high electron-hole separation and narrow bandgap for SDT in BC. Density functional theory (DFT) calculations and experiments collectively demonstrate that the bandgap of TiO2-Ru-PEG is reduced due to the Schottky heterojunction with the characteristic of crystalline-amorphous interface formed by the deposition of ruthenium (Ru) within the shell layer of TiO2. Thanks to the enhancement of oxygen adsorption and the efficient separation of electron-hole pairs, TiO2-Ru-PEG promotes the generation of reactive oxygen species (ROS) under ultrasound (US) irradiation, resulting in cell cycle arrest and apoptosis of bladder tumor cells. The in vivo results prove that TiO2-Ru-PEG boosted the subcutaneous and orthotopic bladder tumor models while exhibiting good safety. This study adopts the ruthenium complex for optimizing sonosensitizers, contributing to the progress of SDT improvement strategies and presenting a paradigm for BC therapy.

Layered double hydroxides derived prussian blue analogue nanocage confining NiCoP nanoparticles as efficient bifunctional electrocatalyst

Designing novel electrocatalysts with excellent catalytic activity for efficient water splitting is necessary to achieve the large-scale H2/O2 production from renewable resources. In this study, a facile hydrothermal method followed by low-temperature phosphorylation treatment was employed to fabricate a nanocage of prussian blue analogue encapsulating NiCoP nanoparticles (NiCoP@PBA), which was derived from the layered double hydroxide precursor. As a bifunctional non-precious metal electrocatalyst, NiCoP@PBA demonstrates superior performance in KOH electrolyte water splitting, with overpotentials of 59 mV for electrocatalytic hydrogen evolution reaction (HER) and 263 mV for oxygen evolution reaction (OER) at 10 mA cm−2. The catalyst also exhibits low Tafel slopes of 54 mV dec−1 for HER and 120 mV dec−1 for OER, reflecting efficient charge transfer kinetics. DFT simulations show that the Co–N moieties at the heterogeneous interface of NiCoP@PBA can optimize the surface electron distribution and energy states, thus facilitating efficient electron-hole pair separation, significantly enhancing catalytic activity for both HER and OER process, and significantly extending the electrocatalyst's service life. Our approach can be extended to more non-precious metal electrocatalysts, which is significant for the design of efficient bifunctional water splitting electrocatalysts.

S-type heterojunction enhance the photocatalytic activity of TiO2/AgBr/Ag using loofah sponge as template towards ciprofloxacin degradation

Photocatalyst TiO2/AgBr/Ag (TBA) composites using loofah sponge as a template were successfully prepared for the first time. The photocatalytic activities of the TBA composites were evaluated by removing ciprofloxacin (CIP) under visible light. The PDOS shows that the valence band edge of TBA-30 is primarily composed of Ti 3d atom states, with small contributions from O 2p atom states. The conduction band edge is dominated by Ag 4d and O 2p atom states, with minor contributions from Br 4p atom states. TBA-30 composites demonstrate outstanding photocatalytic performance, degrading 87% of the target within 180 min. The degradation rate of CIP decreased to 70.19% after five runs, Furthermore, the TOC removal efficiency of CIP reached 84.2% in the end. CIP intermediates and degradation pathway were determined by GC-MS. Three-dimensional excitation-emission matrix fluorescence spectra (3D EEM) were used to study the degradation of CIP molecules. Trapping experiments and electron paramagnetic resonance (EPR) characterisation identified superoxide (·O2-) and photogenerated holes (h+) as the primary active radicals. Furthermore, formed S-type heterojunction and Ag as the electron capture site enhanced the separation efficiency of photoinduced electron-hole pairs. The DFT calculation was used to study the electron transport performance of TBA-30 by calculating the charge density difference.

Carbon-doped Bi2MoO6 nanosheet self-assembled microspheres for photocatalytic degradation of organic dyes

Abstract In this paper, carbon-doped Bi2MoO6 (C-Bi2MoO6) nanosheet self-assembled microspheres were prepared by using the solvothermal-calcination route to improve the photocatalytic activity of Bi2MoO6. The characterization results of x-ray diffractometry, Fourier transform infrared spectrometry, Raman scattering, scanning electron microscopy, transmission electron microscopy, BET specific surface area test, and x-ray photoelectron spectrometry indicated that C replaced the O2− anion in the Bi2MoO6 lattice, thinning the nanosheets, decreasing the size of the microspheres, and increasing the specific surface area of the Bi2MoO6. Ultraviolet–visible diffuse reflectance spectroscopy, photoluminescence, electrochemical impedance spectroscopy, transient photocurrent, and linear sweep voltammetry (LSV) spectroscopy demonstrated that the carbon doping reduced the band gap energy, raised the conduction band, and enhanced the photogenerated electron–hole pairs separation efficiency of Bi2MoO6. Benefiting from these favorable changes, the C-Bi2MoO6 microspheres prepared at a molar ratio of C to Bi of 4 (4C-Bi2MoO6) exhibited the highest photocatalytic activity, and the photocatalytic degradation rate constant of rhodamine B by 4C-Bi2MoO6 microspheres was almost 2.26 times that by pristine Bi2MoO6 under simulated solar light. 4C-Bi2MoO6 microspheres (0.2 g/L) presented excellent photocatalytic performance toward RhB (20 mg/L) at pH value 1 and could remove 98.31% of the RhB within 120 min. In addition, 4C-Bi2MoO6 microspheres also possessed a high photocatalytic activity toward methylene blue and tetracycline. 4C-Bi2MoO6 microspheres assembled from thin nanosheets can be used as effective photocatalysts to degrade toxic organic molecules from wastewater.

BiOCl/BiOBr composites for efficient photocatalytic carbon dioxide reduction

BiOBr (BOB) photocatalysts have low photocatalytic CO2 reduction performance due to their low electron-hole pair separation efficiency. To improve this problem, BiOCl (BOCl) is used as a co-catalyst. BOCl is loaded into BOB to form BiOCl/BiOBr (BOCl/BOB) type Ⅰ heterojunction, which enhances the photocatalytic CO2 reduction performance of BOB by promoting the separation of photogenerated electrons and holes. The results of TPR and PL experiments show that the 20% BOCl/BOB composites have the highest photogenerated carrier separation rate, and the results of CO2 reduction experiments show that 20% BOCl/BOB composites have the best photocatalytic CO2 reduction performance of 7.353 μmolg−1h−1, which is 3.22 and 1.99 times higher than pure BOB and BOCl, respectively. This work provides an effective reference for the development of modified photocatalysts.

Indium sulfide-sensitized 2D stannum indium sulfide nanosheet arrays promoting photoelectrochemical conversion efficiency in cathodic protection

This study reports the fabrication of 2D stannum indium sulfide (SnIn4S8) nanosheet arrays sensitized with indium sulfide (In2S3) and their potential application as photoanodes in photoelectrochemical cathodic protection for 304 stainless steel. The deposition of In2S3 flakes on the surface of the SnIn4S8 nanosheet arrays induces a notable alteration in the optical absorption of the composite samples, showing a maximum redshift from 560 nm to 645 nm. The incorporation of In2S3 regulates the energy band structure of SnIn4S8 by pulling its Fermi level and valence band maximum toward a negative direction. The type II heterojunction formed by sensitization with In2S3 strengthens the separation efficiency of photoinduced carriers in SnIn4S8, inhibiting self-corrosion. The particular 5%-In2S3/SnIn4S8 composite demonstrates a notable shift in the mixed potential toward negative values, reaching a potential of −1.05 V when exposed to visible light. An excessive amount of In2S3 is not conducive to the directional flow of carriers at the heterojunction interface, preventing efficient separation of electron-hole pairs. This research highlights the advantages of the In2S3-sensitized SnIn4S8 composites for photogenerated cathodic protection.

Dynamic Ag-mediated electron transfer confined ZnO nanorods for boosted photocatalytic bacterial disinfection

Infectious diseases, particularly bacterial infections, pose a global crisis with significant impacts on public health and economic stability due to the emergence of multi-drug resistance and limitations in existing therapeutic options. The present study focused on the development of photocatalytic disinfectant and silver-decorated hexagonal zinc oxide nanorods (Ag/ZnO NRs) were fabricated through an ultrasonic-assisted solvothermal method, and investigated for the photocatalytic inactivation on E. coli. The morphological, structural, and optical characteristics of the fabricated Ag/ZnO NRs were systematically studied through various analytical techniques. Here, 3%Ag/ZnO NRs showed 96.9% inactivation of E. coli within 120 min of visible light irradiation. The excellent inactivation efficiency of the photocatalyst could be attributed to the higher charge carrier mobility, efficient electron-hole pair separation, and highvisible light harvesting ability. The Schottky heterojunction was proposed as a possible mechanism for the photoinactivation of E. coli. Further, the impacts of different dosages of nanocomposites (NCs) and varying pH on bacterial inactivation were studied under visible light exposure. The reusability and stability of the NCs were investigatedfor 6 consecutive cycles of photoinactivation and it showed excellent efficiency (91.16%) of the photocatalyst for prolonged usage. The real-time application was assessed using reclaimed wastewaterand the influence on the organic matter was determined using COD analysis. The proposed study offers a significant point reference for the practical application of photocatalysis forthe inactivation of antibiotic-resistant microbes present in water bodies and environmental wastewater.

Z-scheme heterojunction engineering and hole-extraction layer enable efficient photoelectrochemical water splitting on BiVO4 photoanode

This study presents a novel Z-scheme heterostructure that was developed by integrating three-dimensional CoFe2O4 nanospheres with Mo and W co-doped BiVO4 (MW:BVO). Subsequently, ultra-thin hydroxides (NiOOH-FeOOH) were grown on the surface of the MW:BVO@CFO photoanode in the presence of tannic acid (TA), resulting in the formation of MW:BVO@CFO/TANF photoanodes. Notably, TANF served as a hole extraction layer. Compared to pristine MW:BVO, the photocurrent density of MW:BVO@CFO/TANF photoanodes exhibited a significant enhancement from 0.96 mA/cm2 to 6.03 mA/cm2 at 1.23 VRHE with a charge separation efficiency of 90.2 % due to the synergistic effect of the Z-scheme structure and hole extraction layer. Notably, the Z-scheme architecture facilitates the effective separation and transfer of electron-hole pairs, thereby retaining electrons and holes with high redox capacity. Meanwhile, the hole extraction layer quickly exports and aggregates the photo-generated holes, thereby further improving the separation efficiency of electron-hole pairs.