Separation Of Carriers Research Articles

Reinforcing Photogenerated Carrier Extraction of Environment‐Friendly InP/ZnSeS Quantum Dots for High‐Performing Photoelectrochemical Photodetection and Solar Energy Conversion

AbstractColloidal InP/ZnSeS‐based quantum dots (QDs) are considered promising building blocks for light‐emitting devices due to their environmental friendliness, high quantum yield (QY), and narrow emission. However, the intrinsic type‐I band structure severely hinders potential photoelectrochemical (PEC) applications requiring efficient photoexcited carrier separation and transfer. In this study, the optoelectronic properties of InP/ZnSeS QDs are tailored by introducing Al dopants in the ZnSeS layer, which concurrently passivate the surface defects and act as shallow donor states for suppressed non‐radiative recombination and improved charge extraction efficiency. Consequently, as‐fabricated InP/ZnSeS:Al QDs‐based PEC‐type photodetector exhibited a high detectivity up to 1011 Jones and a remarkable responsivity of 0.66 A W−1 at 600 nm even under self‐powered condition (0V bias). In addition, as‐prepared InP/ZnSeS:Al QDs‐based photoanode can be alternatively used for PEC hydrogen generation, showing an H2 production rate of 73.7 µmol cm−2 h−1 under 1 sun illumination (AM 1.5G, 100 mW cm−2). The results offer a prospective strategy for optimizing eco‐friendly QDs for high‐performance multifunctional light detection/conversion devices.

Modulating Pore Wall Chemistry Empowers Sonodynamic Activity of Two‐Dimensional Covalent Organic Framework Heterojunctions for Pro‐Oxidative Nanotherapy

AbstractCovalent organic frameworks (COFs) have garnered growing interest in the field of biomedicine; however, their application in sonodynamic therapy remains underexplored due to limited understanding of their intrinsic activity and structure–property relationships. Here, we present a pore wall chemistry modulation strategy for empowering sonodynamic activity to two‐dimensional (2D) COF heterojunctions through in situ growth of COFs on bismuth oxycarbonate nanosheets (B NSs). Compared to the negligible sonodynamic effects observed in the pristine B NSs, the 2D heterojunction with vinyl‐decorated COF pore walls demonstrates a 3.6‐fold enhancement in sonocatalytic singlet oxygen generation. This performance also significantly outperforms that of isoreticular COFs functionalized with methoxy or non‐substituted groups. Mechanistic studies reveal that the vinyl groups in the B@COF (BC) heterojunction facilitate the separation and transfer of charge carriers while also enhancing the adsorption of oxygen molecules. Furthermore, peroxymonosulfate (PMS) loading into the porous COFs boosts the therapeutic efficacy of antitumor nanotherapy via sonocatalytic dual oxidative species generation. These findings underscore the critical role of pore wall chemistry in modulating the sonocatalytic properties of COFs, and advance the development of COF‐based sonosensitizers for pro‐oxidative applications.

Structure Engineering of Ga2O3 photodetectors: A Review

Abstract Deep ultraviolet (DUV) photodetectors play important roles in the modern semiconductor industry due to their diverse applications in critical fields. Wide bandgap semiconductor Ga2O3 is considered as one promising material for highly sensitive DUV photodetectors. However, the high responsivity of Ga2O3 DUV photodetectors always comes at the expense of its response speed. Material engineering for high-quality Ga2O3 materials can optimize the photoresponse performance but at the cost of much more complex process. Structure engineering can efficiently improve the performance of Ga2O3 photodetectors based on various physical mechanisms. Owing to the increased modulation probabilities, part schemes of structure engineering even alleviate the tough requirements on Ga2O3 material quality for high-performance DUV photodetectors. This article reviews the recent efforts in optimizing the performance of Ga2O3 photodetectors through structure engineering. Firstly, photodetectors based on Ga2O3 nanostructures and metasurface structures with nanometer size effect are discussed. In addition, junction structures of Ga2O3 photodetectors, which effectively promote carrier separation in the depletion region, are summarized based on a classification of Schottky junction, heterojunction, phase junction, etc. Besides, Ga2O3 avalanche photodiodes, offering ultra-high gain and responsivity, are focused as a promising prototype for commercialization. Furthermore, field effect phototransistors, based on which the scalability and low power performance of Ga2O3 photodetectors have been well proven, are analyzed in detail. Moreover, auxiliary-field configurations with extra tunable dimensions for Ga2O3 photodetectors are introduced. Finally, we conclude this review and discuss the main challenges of Ga2O3 DUV photodetectors from our perspective.

Structural Design on Porous Aromatic Frameworks for Photocatalysis

Photocatalytic technology has shown great potential in various fields such as environmental purification, energy conversion, and chemical transformations due to its green, sustainable, and low‐cost characteristics. Porous aromatic frameworks (PAFs) with high specific surface areas, designable local structures, and abundant active sites could potentially serve as efficient photocatalysts for various catalytic reactions. This makes PAFs have a wide range of application prospects and significant advantages in the field of photocatalysis. This concept discusses the recent progress of photocatalysis over PAFs. Various strategies are used to solve the general problems of photocatalyst, such as poor light absorption, low carrier separation efficiency and poor stability, which further reveal the relationship between their structure and performance.

Creating Cation Vacancies in BiOCl Nanosheets Toward Exceptional Visible‐Light‐Driven Photocatalytic CO2 Reduction

AbstractBiOCl‐based materials have emerged as promising photocatalysts for converting CO2 into valuable products and fuels. However, challenges such as low light absorption and inefficient charge carrier separation require effective solutions, with vacancy engineering offering a promising approach. Current research primarily focuses on anion vacancies, leaving cation vacancies less explored. In contrast, this study presents a novel method to enhance visible‐light‐driven photocatalysts by Bi cation vacancies in ultrathin BiOCl nanosheets through a straightforward hydrochloric acid etching process (HAE‐BiOCl). These introduced Bi vacancies not only expand the light absorption range and enhance carrier separation, but also serve as active sites for CO2 adsorption. Additionally, Bi vacancies can effectively lower the activation energy of COOH− species and thereby enhance overall reaction activity. As a result, the HAE‐BiOCl catalyst exhibits exceptional photocatalytic CO2 reduction performance without the need for co‐catalysts or sacrificial agents. It achieves high CO generation rates of 68.39 and 17.43 µmol g−1 h−1 under 300 W Xe lamp and visible light irradiation, respectively. These rates are significantly higher compared to counterparts without vacancy creation and surpass those of most reported Bi‐based photocatalysts. This study underscores the potential of inducing cation vacancies via acid etching as a valuable strategy for advancing photocatalysis.

A superlattice interface and S-scheme heterojunction for ultrafast charge separation and transfer in photocatalytic H2 evolution

The rapid recombination of photoinduced charge carriers in semiconductors fundamentally limits their application in photocatalysis. Herein, we report that a superlattice interface and S-scheme heterojunction based on Mn0.5Cd0.5S nanorods can significantly promote ultrafast charge separation and transfer. Specifically, the axially distributed zinc blende/wurtzite superlattice interfaces in Mn0.5Cd0.5S nanorods can redistribute photoinduced charge carriers more effectively when boosted by homogeneous internal electric fields and promotes bulk separation. Accordingly, S-scheme heterojunctions between the Mn0.5Cd0.5S nanorods and MnWO4 nanoparticles can further accelerate the surface separation of charge carriers via a heterogeneous internal electric field. Subsequent capture of the photoelectrons by adsorbed H2O is as fast as several picoseconds which results in a photocatalytic H2 evolution rate of 54.4 mmol·g−1·h−1 without any cocatalyst under simulated solar irradiation. The yields are increased by a factor of ~5 times relative to control samples and an apparent quantum efficiency of 63.1% at 420 nm is measured. This work provides a protocol for designing synergistic interface structure for efficient photocatalysis.

Eco-friendly synthesis and surface modification of ZnO nanoparticles using Pueraria montana root extract: enhanced photocatalytic performance with trisodium pyrophosphate

ABSTRACT The synthesis of zinc oxide (ZnO) nanoparticles using Pueraria montana (kudzu) plant extracts highlights advancements in green nanotechnology. This study explores the use of Pueraria montana roots, rich in phytochemicals such as phenols, terpenoids and flavonoids, which serve as natural reducing and stabilizing agents for nanoparticle synthesis. The eco-friendly production and surface modification of ZnO nanoparticles were achieved using these plant extracts, enhancing their photocatalytic performance with trisodium pyrophosphate (TSPP).Characterization techniques, including XRD, TEM, and FE-SEM, confirmed the nanoparticles’ crystalline structure, with a BET surface area of 14.01 m²/g and a type II adsorption isotherm. The synthesized nanoparticles exhibited exceptional dye degradation capabilities, achieving 99.9% removal of malachite green (MG) and 97.78% for aniline blue (AB). Kinetic analysis revealed a steady-state rate constant (k) of 2 × 10⁻⁴ min⁻¹ for MG where as the response rate constant(k) for the photocatalytic degradation of AB using modified ZnO nanostructures was 3.0 × 10−3 min−1 allowing near-total dye removal within 600 minutes for MG and 350 min for AB . Adsorption studies were well described by Langmuir and Freundlich isotherms, indicating maximum adsorption capacities of 59.7 mg/g for MG and 61.2 mg/g for AB. Surface modification with TSPP improved charge carrier separation and enhanced the generation of reactive oxygen species under UV exposure, further increasing dye degradation efficiency.Statistical analysis indicated high reproducibility, with close mean adsorption values of 99.125 for MG and 97.3125 for AB, supported by small standard deviations. The findings affirm the potential of using Pueraria montana in synthesizing efficient photocatalysts, providing a sustainable and cost-effective approach for water treatment applications. Overall, this research underscores the effectiveness of plant-based materials in advancing eco-friendly nanotechnology solutions.

Synchronous photocatalytic benzimidazole formation and olefin reduction by magnetic separable visible-light-driven Pd-g-C3N4-Vanillin@γ-Fe2O3-TiO2 Nanocomposite

A visible light-responsive magnetically separable photocatalyst Pd-g-C3N4-Vanillin@γ-Fe2O3-TiO2 is fabricated using vanillin as a natural junction under ultrasonic agitation. Structural, morphological, optical, thermal, and magnetic assessments of the as-prepared catalyst are carried out. The photocatalyst successfully drives the simultaneous benzimidazole formation, and olefin hydrogenation with high atom economy under blue LED light and mild conditions. The photocatalytic activity of Pd-g-C3N4-Vanillin@γ-Fe2O3-TiO2 is significantly affected by the γ-Fe2O3:TiO2 weight ratio. PL spectra revealed the effective separation of carriers in the fabricated catalyst promoting its photocatalytic activity. The action spectra using the apparent quantum efficiency (AQE) exhibited the maximum AQEs at 520 and 750 nm in which the highest performance for styrene hydrogenation is observed. The title magnetically separable heterogeneous photocatalyst provides high yields of products under perfectly safe visible light, produces low/zero waste, and avoids using an external high-pressure hydrogen gas source, harmful solvents, undesirable additives, and reducing agents rendering green conditions for chemical reactions.

Bi2Te3/Carbon Nanotube Hybrid Nanomaterials as Catalysts for Thermoelectric Hydrogen Peroxide Generation

Harnessing waste heat from environmental or industrial sources presents a promising approach to eco-friendly and sustainable chemical synthesis. In this study, we introduce a thermoelectrocatalytic (TECatal) system capable of utilizing even small amounts of heat for hydrogen peroxide (H2O2) production. We developed a nanohybrid structure, combining carbon nanotubes (CNTs) and Bi2Te3 nanoflakes (Bi2Te3/CNTs), through a one-pot synthesis method. Bi2Te3, as a thermoelectric (TE) material, generates charge carriers under a temperature gradient via the Seebeck effect, enabling them to participate in surface redox reactions. However, the rapid recombination of these charge carriers greatly limits the TECatal activity. In the Bi2Te3/CNTs nanohybrid system, the introduction of CNTs substantially enhances the efficiency of H2O2 production, as the strong bonding between CNTs and Bi2Te3, along with the excellent conductivity of CNTs, facilitates charge carrier separation and transport, as confirmed by TE electrochemical tests. This study underscores the significant potential of thermoelectric nanomaterials for converting waste heat into green chemical synthesis.

Z-Scheme Enabled 1D/2D Nanocomposite of ZnO Nanorods and Functionalized g-C3 N4 Nanosheets for Sustainable Degradation of Terephthalic Acid.

The urgent need to mitigate water pollution and achieve Sustainable Development Goal 14 (SDG 14)-Life below water, necessitates developing efficient and eco-friendly wastewater treatment technologies. This research addresses this challenge by photocatalytic degradation of terephthalic acid, a precursor for PET bottles using environment-friendly and biocompatible photocatalysts. The 1D/2D nanocomposite comprising zinc oxide (ZnO) nanorods and functionalized graphitic carbon nitride (Zn-TG) nanosheets were synthesized and thoroughly characterized. The nanocomposite effectively mitigated the individual drawbacks of Zn-TG agglomeration and the wide band gap of ZnO as confirmed through zeta potential and Tauc's plot studies, respectively. The synthesized nanocomposite achieved ~100 % degradation within 60 minutes, exhibiting superior kinetics (~2.5 times) compared to pristine samples. The enhanced degradation efficiency was elucidated by efficient charge carrier transfer (~5 times faster) and separation (~2 times improved) as confirmed through electrochemical impedance spectroscopy and time-resolved photoluminescence studies. The proposed Z-scheme pathway provides mechanistic insights. This proposed mechanism is supported by extensive electron paramagnetic resonance (EPR) and scavenger studies. The liquid chromatography-mass spectrometry (LC-MS) analysis confirms the formation of less toxic byproducts for ensuring that the wastewater treatment process is efficient and environmentally friendly. This research helps in developing a highly effective and sustainable wastewater treatment technology.

A Facile Microwave-Promoted Formation of Highly Photoresponsive Au-Decorated TiO2 Nanorods for the Enhanced Photo-Degradation of Methylene Blue

The integration of noble metal nanoparticles (NPs) effectively modifies the electronic properties of semiconductor photocatalysts, leading to improved charge separation and enhanced photocatalytic performance. TiO2 nanorods decorated with Au NPs were successfully synthesized using a cost-effective, rapid microwave-assisted method in H2O2 and HF media for methylene blue (MB) degradation under visible light illumination. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 physisorption, and UV–vis spectroscopy were employed to characterize the structures, morphologies, compositions, and photoelectronic properties of the as-synthesized materials. The fusing of Au NPs effectively alters the electronic structure of TiO2, enhancing the charge separation efficiency and improved electrical conductivity. The HF treatment promotes the exposure of the highly reactive (001) and (101) crystalline facets. The improved photocatalytic activity of Au/TiO2, achieving 97% efficiency, is attributed to the surface plasmon resonance (SPR) effect of the Au NPs and the presence of oxygen vacancies. The photodegradation of MB using the TiO2/Au photocatalysts follows pseudo-first-order kinetics, highlighting the enhanced catalytic efficiency of the synthesized nanostructures. The exceptional properties of the binary Au/TiO2 photocatalysts, including the SPR effect, exposed crystallographic faces, and efficient charge carrier separation through a decrease in the recombination of electrons and holes, contribute to the photocatalytic degradation of MB.

Enhanced Degradation of Norfloxacin Under Visible Light by S-Scheme Fe2O3/g–C3N4 Heterojunctions

S-scheme Fe2O3/g–C3N4 heterojunctions were successfully fabricated by the ultrasonic assistance method to remove norfloxacin (NOR) under visible light irradiation. The synthesized catalysts were well studied through various techniques. The obtained Fe2O3/g–C3N4 heterojunctions exhibited an optimal photocatalytic degradation of 94.7% for NOR, which was 1.67 and 1.28 times higher than using Fe2O3 and g–C3N4 alone, respectively. In addition, the kinetic constant of NOR removal with Fe2O3/g–C3N4 composites was about 0.6631 h−1, and NOR photo-deegradation was still 86.7% after four cycles. The enhanced photocatalytic activity may be mainly attributed to the formation of S-scheme Fe2O3/g–C3N4 heterojunctions with built-in electric fields, which were beneficial to the separation and transfer of photostimulated charge carriers. Furthermore, a possible photo-degradation mechanism of NOR for S-scheme Fe2O3/g–C3N4 heterojunctions is described.

Enhanced photocatalytic degradation of organic pollutants by randomly oriented 2D SnS2 nanostructures

Abstract In this study, we present a bottom-up solvothermal technique using tin tetrachloride pentahydrate (SnCl4.5H2O) and thioacetamide as precursors to synthesize SnS2 nanostructures. Different solvents including isopropyl alcohol, ethanol (EN), and ethylene glycol were used in the reaction to enhance the photodegradation efficiency of organic pollutants, Methylene Blue (MB), and Tetracycline (TC) in an aqueous medium under simulated solar light irradiation. The SnS2 nanostructures synthesized with these solvents were characterized using various structural, morphological, and optical techniques, including x-ray diffraction, RAMAN, field emission scanning electron microscope, x-ray photoelectron spectroscopy, UV–Vis, and Brunauer–Emmett–Teller analysis. The choice of solvent was found to significantly affect the structural, morphological, and optical properties of the SnS2 nanostructures. Notably, the sample synthesized with EN as the solvent displayed a unique morphology, enhanced light-harvesting ability, efficient charge carrier separation, and a larger specific surface area, all of which contributed to its superior photocatalytic activity. This sample achieved 99.9% degradation of MB and 95% degradation of TC within 20 and 40 min, respectively. The kinetic analysis revealed maximum rate constant (k) values of 0.15242 min−1 for MB and 0.060 95 min−1 for TC, as determined by the pseudo-first-order kinetic model. We also discuss the plausible mechanism involving visible light-induced electron–hole pairs that generate reactive species, leading to the mineralization of dyes into H2O, CO2, and other gaseous products. The synthesized SnS2 nanostructures demonstrate significant potential for enhanced photocatalytic activity in organic pollutant degradation, underscoring their promise in addressing water pollution challenges.

Photocatalytic performance of Ni-Al LDH @Ag2XO4 (X = Cr, Mo, and W) nanocomposites under visible light

The contamination of water sources from dye discharge poses a significant environmental challenge. This study addresses this issue by synthesizing binary composites of Ni-Al LDH@Ag2XO4 (with X=Cr, Mo, and W). The main goal is to increase the separation of charge carriers to boost the efficiency of photocatalysis. The prepared samples were analyzed using FT-IR, FE-SEM, EDS, FE-TEM, XRD, UV–Vis DRS, and XPS techniques. Observations revealed a notable increase in MB degradation through photocatalysis under a 150 W mercury lamp in presence of Ni-Al LDH@Ag2CrO4 compared to individual samples, Ni-Al LDH and Ag2CrO4. At pH= 11, 0.5 g of Ni-Al LDH@Ag2CrO4 shows the highest activity (100 %) for the photodegradation of MB. The absorption edge of Ni-Al LDH@Ag2CrO4 (1.69 eV) has increased compared to that of Ni-Al LDH (2.53 eV), which increases the light absorption capacity. Moreover, the synergistic effect of Ni-Al LDH and Ag2CrO4 increases photocatalytic activity by reducing electron-hole recombination. The proposed Z-Scheme mechanism confirms effective charge separation and increased photocatalytic efficiency.

Advanced plasmonic few-layered InSe nanosheet heterojunctions for enhanced photoelectrochemical water splitting

The selenide-based Van der Waals heterojunctions show great potential for the next generation of photoelectronic nanodevices. Herein, we construct a 2D photoanode nanocatalyst that consists of ZnSe nanocrystals with exposed active surfaces coupled with few-layered InSe nanosheets decorated by Au nanoparticles. The resultant ZnSe/AuNPs@InSe multi-heterojunction photoanode demonstrates an outstanding photocurrent density of 4.86 mAcm−2 under AM 1.5 G simulated sunlight (100 mWcm−2), which is 8 times greater than that of the pristine InSe photoanode (0.61 mAcm−2). Moreover, the lifetime of photogenerated charge carriers is extended by a factor of 3. This significant enhancement in photoelectrochemical water splitting in the near-infrared region is attributed to the surface plasmonic effect produced by the modification of Au NPs when bulk InSe is exfoliated into multi-layered flakes. The interfacial coupling effects on carrier transfer dynamics, as revealed by impedance spectroscopy assisted with the First-Principal calculations, show that this photoanode significantly minimizes the internal resistance, boosts the charge carrier separation efficiency, and promotes water oxidation.

G-C3N4 coupled with GO accelerates carrier separation via high conductivity for photocatalytic MB degradation

Graphitic carbon nitride (g-C3N4) is widely utilized in photocatalysis due to its responsiveness to visible light, low cost, and non-toxicity. However, its efficiency is limited by factors such as the rapid recombination of photogenerated electron-hole pairs, slow electron transfer rates, and a limited number of active surface sites. In this study, g-C3N4 was synthesized through thermal polymerization, and varying amounts of graphene oxide (GO) were incorporated via physical blending to fabricate composite photocatalysts. The results indicated that the incorporation of GO not only increased the specific surface area and modified the pore size distribution of g-C3N4 but also affected the heptazine ring structure through chemical bonding, thereby enhancing the density of active sites. Photocatalytic degradation experiments with methylene blue (MB) indicated that g-C3N4 containing 2% GO exhibited photocatalytic activity 2.84 times greater than that of pristine g-C3N4. Kinetic simulations indicated that the Kapp value for the 2% GO-g-C3N4 composite was 0.00469min-1, which is 4.34 times higher than that of pure g-C3N4 (0.00108min-1). Furthermore, this composite maintained high photocatalytic activity after four cycles of reuse. An analysis of the photocatalytic degradation mechanism revealed that the incorporation of GO effectively promoted the separation and transfer of photogenerated electron-hole pairs, enhanced photocurrent density, and improved carrier separation efficiency. Electron spin resonance (ESR) and free radical scavenging experiments confirmed that the primary active species involved in the degradation of MB by the composite photocatalyst were ·O2- and h+. This study presents a novel approach for enhancing the photocatalytic performance of g-C3N4 by modifying its electronic structure and surface properties.

Bio-inspired synthesis of Ag-g-C3N4 nanocomposites and their application for photocatalytic degradation of para-nitrophenol

Nanocomposites are promising in advanced materials for environmental applications due to their ability to boost functionality through synergistic effects. Graphitic carbon nitride (g-C3N4) is renowned for its exceptional characteristics in photocatalysis. This work examines the preparation of g-C3N4 from different precursors, and how the presence of silver nanoparticles (Ag NPs) and silver ions (Ag+) in g-C3N4 matrices improve their combined effect on photocatalytic activity, specifically in the degradation of para-nitrophenol (PNP), a persistent organic pollutant. From urea and melamine precursors for the preparation of g-C3N4, the latter provided a much higher yield. Using an easy synthesis approach, Ag NPs were evenly distributed in the g-C3N4 framework, whereas Ag+ ions were incorporated by an apparent physical procedure. A bio-inspired, environmentally friendly method was also applied to prepare Ag NPs. The nanocomposites showed improved light absorption and separation of charge carriers due to the synergistic interaction between g-C3N4 and Ag species. Using UV and Vis LED light sources, we investigated both pure g-C3N4 and Ag-g-C3N4 catalysts. For breaking down para-nitrophenol, the silver-modified catalysts performed significantly better than pure g-C3N4 in both UV and Vis. The study clarified the functions of Ag NPs and Ag+ ions in enhancing photocatalytic activity by examining their involvement in generating reactive oxygen species and degrading pollutants. This work highlights the capability of g-C3N4-based nanocomposites as effective photocatalysts for environmental remediation. It also explores the benefits of adding silver species to improve performance in degrading pollutants.

The Fabrication of BiVO4/WO3/GaN Heterojunction and its Enhanced Water Splitting Performance

Abstract GaN has garnered significant attention for water splitting due to its excellent light absorption, carrier transport properties, and chemical inertness. However, its bandgap of 3.4 eV restricts absorption to the ultraviolet range. To address this limitation, narrow-bandgap semiconductors BiVO4 and WO3 were deposited on the GaN surface using the sol-gel method. Photoelectrochemical water-splitting tests revealed that the saturated photocurrent densities of GaN/BiVO4 and GaN/BiVO4/WO3 under full-spectrum illumination were 1.42 and 1.86 times greater than that of GaN alone, respectively. This improvement is attributed to the smaller bandgaps of BiVO4 and WO3, which significantly extend the spectral absorption range of GaN. Additionally, BiVO4 and WO3 form heterojunctions through energy alignment, and the built-in electric field at the heterojunctions accelerates the separation of photo-generated carriers, further enhancing energy conversion efficiency. The study also found that the BiVO4 and WO3 films exhibit a 2D flake morphology, providing larger surface areas that enhance light absorption and carrier transport, thereby improving water-splitting efficiency. Our research paves a new path for the application of GaN in water splitting.

Efficient photocatalytic activity over α-MnS/ZIF-67 p-n junction: Revealing the synergistic effects of exposed crystal facets and built-in electric field mechanism

In this investigation, we explored two series of composites comprising p-type α-MnS with selectively exposed {001} or {111} facets, coated with n-type ZIF-67 nanoparticles, to enhance the photocatalytic activity on Rhodamine B (RhB) degradation. The influence of the crystal facet orientation and the p-n junction on the photocatalytic efficacy was also well studied. The α-MnS/ZIF-67 composites displayed enhanced separation of charge carriers and superior light absorption capabilities, benefiting for efficient photocatalysis. The composites with cubic α-MnS morphology exhibited a pronouncedly higher photocatalytic activity relative to those with octahedral α-MnS morphology. The composition of α-MnS with ZIF-67 constructed the formation of a p-n junction with build-in electric field, extending the response into the visible region and promoting the mobility of charge carriers, thereby improving the photocatalytic performance. Our findings revealed that superoxide radicals (O2-) were the major reactive species in the photocatalytic degradation process. This study contributes novel insights into the development of high-performance and stable metal-organic framework (MOF)-based photocatalysts through the crystal facet engineering and the construction of p-n junctions.

Fermi energy level synergistic Bi-based electron bridge construction of Z-type heterojunctions to accelerated photogenerated charge transfer for photostability and contaminant mineralization

Advanced oxidation technologies offer new opportunities for pollutant degradation. Despite the existence of numerous photocatalyst heterojunctions for advanced oxidation, their charge transfer and separation efficiency is low due to inadequate interfacial modulation, especially for Type II heterojunctions. Here, through metal reduction, metal defects with regulating the Fermi level and metal electron bridges with facilitate the separation of photo-generated carriers, facilitating the transition from Type II to Z-type heterojunctions. Herein, we designed a Z-Scheme photocatalyst with Bi-based electron bridges (referred to as ‘fishbone-like’ BiVO4/Bi/CuO) synthesized through in situ reduction, utilized for RhB degradation. Under visible light irradiation, the degradation rate of RhB up to 99 % within 120 min, outperforming most previously reported photocatalysts. Notably, the well-designed BiVO4/Bi/CuO exhibits as reaction rate of 4.13 × 10-2 ·min−1, which is 18 times higher than the pure BiVO4. The BiVO4/Bi/CuO photocatalyst demonstrates exceptional stability over 6 reaction cycles spanning 15 h, due to strengthened contact interface of BiVO4/Bi/CuO. The metal Bi can induce the surface plasmon resonance (SPR) effect, enhancing light absorption. Furthermore, Bi-based electron bridges significantly promote the charge transfer across the Z-type heterojunction interface, which were verified by assorted experimental outcomes and density functional theory (DFT) calculations. This work represents a promising platform for the development of highly efficient and stable photocatalysts that have potential in Pollutant degradation applications.