High Charge Transfer Efficiency Research Articles

Hydrophilic ZnO/C nanocomposites with superior adsorption, photocatalytic, and photo-enhanced antibacterial properties for synergistic water purification

Owing to the numerous potential applications of ZnO nanomaterials, the development of ZnO-based nanocomposites has become of great scientific interest in various fields. In this paper, we are reporting the fabrication of a series of ZnO/C nanocomposites through a simple “one-pot” calcination method under three different temperatures, 500 ℃, 600 ℃, and 700 ℃, with samples labeled as ZnO/C-500, -600, and -700, respectively. All samples exhibited adsorption capabilities and photon-activated catalytic and antibacterial properties, with the ZnO/C-700 sample showing superior performance among the three. The carbonaceous material in ZnO/C is key to expanding the optical absorption range and improving the charge separation efficiency of ZnO. The remarkable adsorption property of the ZnO/C-700 sample was demonstrated using Congo red dye, and is credited to its good hydrophilicity. It was also found to exhibit the most notable photocatalysis effect due to its high charge transfer efficiency. The hydrophilic ZnO/C-700 sample was also examined for antibacterial effects both in vitro (against Escherichia coli and Staphylococcus aureus) and in vivo (against MSRA-infected rat wound model), and it was observed to exhibit synergistic killing performance under visible-light irradiation. A possible cleaning mechanism is proposed on the basis of our experimental results. Overall, this work presents a facile way of synthesizing ZnO/C nanocomposites with outstanding adsorption, photocatalysis, and antibacterial properties for the efficient treatment of organic and bacterial contaminants in wastewater.

Nitrogen vacancy/oxygen dopants designed nanoscale hollow tubular g-C3N4 with excellent photocatalytic hydrogen evolution and photodegradation

In this study, N vacancies and O heteroatoms were decorated onto hollow nanotubes carbon nitride (UMCN-3) via hydrolyzation-precipitation-calcination method to prepare high-performance photocatalyst for hydrogen evolution and photodegradation. Plenty of hollow nanotubes with diameter of 30–50 nm endowed UMCN-3 with abundant active sites and high charge transfer efficiency. Nitrogen vacancies/oxygen dopants not only created defect states but also acted as trapping centers, thus triggering the charge rearrangement to obtain high electronic transport efficiency, as evidenced by experimental results and theoretical calculations (DFT). The hydrogen evolution rate of optimal UMCN-3 sample was 23-times higher than that of pristine g-C3N4, and still at a high level in seawater. The photocatalytic degradation activity for RhB and TC of UMCN-3 also improved greatly. The superb photocatalytic performance can be put down to the three-in-one synergistic effect on N vacancies, O doped and hollow nanotubes.

Enhanced piezocatalytic hydrogen evolution performance of bismuth vanadate by the synergistic effect of facet engineering and cocatalyst engineering

Developing piezocatalysts with excellent piezocatalytic hydrogen evolution reaction (HER) performance is highly desired but also challenging. Here, facet engineering and cocatalyst engineering are employed to synergistically improve the piezocatalytic HER efficiency of BiVO4 (BVO). Monoclinic BVO catalysts with distinct exposed facets are synthesized by adjusting pH of hydrothermal reaction. The BVO with highly exposed {110} facet exhibits a superior piezocatalytic HER performance (617.9 μmol g-1h−1) compared with that with {010} facet, owing to the strong piezoelectric property, high charge transfer efficiency, and excellent hydrogen adsorption/desorption capacity. The HER efficiency is enhanced by 44.7% by selectively depositing cocatalyst of Ag nanoparticles specifically on the reductive {010} facet of BVO, where the Ag-BVO interface provides the directional electron transport for high-efficiency charge separation. Under the collaboration between cocatalyst of CoOx on {110} facet and the hole sacrificial agent of methanol, the piezocatalytic HER efficiency is evidently enhanced by 2 times because CoOx and methanol can impede the water oxidation and improve the charge separation. This easy and simple strategy provides an alternative perspective on designing high-performance piezocatalysts.

High-Performance Visible-Light Photocatalysts for H2 Production: Rod-Shaped Co3O4/CoO/Co2P Heterojunction Derived from Co-MOF-74

Photocatalyst systems generally consist of catalysts and cocatalysts to realize light capture, charge carrier migration, and surface redox reactions. Developing a single photocatalyst that performs all functions while minimizing efficiency loss is extremely challenging. Herein, rod-shaped photocatalysts Co3O4/CoO/Co2P are designed and prepared using Co-MOF-74 as a template, which displays an outstanding H2 generation rate of 6.00 mmol·g−1·h−1 when exposed to visible light irradiation. It is 12.8 times higher than pure Co3O4. Under light excitation, the photoinduced electrons migrate from the catalysts of Co3O4 and CoO to the cocatalyst Co2P. The trapped electrons can subsequently undergo a reduction reaction to produce H2 on the surface. Density functional theory calculations and spectroscopic measurements reveal that enhanced performance results from the extended lifetime of photogenerated carriers and higher charge transfer efficiency. The ingenious structure and interface design presented in this study may guide the general synthesis of metal oxide/metal phosphide homometallic composites for photocatalysis.

Dithienobenzothiadiazole (DTBT)-Based Polymers Enable Organic Solar Cells with Ultrahigh VOC of ≈1.3V.

Dithieno[3',2':3,4;2",3":5,6]benzo[1,2-c][1,2,5]thiadiazole (DTBT) is a newly emerging building block to construct effective photovoltaic polymers. Organic solar cells (OSCs) based on DTBT-based polymers have realized power conversion efficiency (PCEs) over 18%, despite their relatively low open-circuit voltage (VOC ) of 0.8-0.95V. To extend the application of DTBT-based polymers in high-voltage OSCs, herein, D18-Cl and PE55 are used to combine with a wide-bandgap non-fullerene acceptor (NFA), BTA3, and achieve ultrahigh VOC of 1.30 and 1.28V, respectively. Compared with D18-Cl based on tricyclic benzodithiophene (BDT) segment, PE55 containing the pentacyclic dithienobenzodithiophene (DTBDT) unit possesses better hole mobility, higher charge-transfer efficiency, and more desirable phase separation. Hence, PE55:BTA3 blend exhibits a higher efficiency of 9.36% than that of D18-Cl: BTA3 combination (6.30%), which is one of the highest values for OSCs at ≈1.3V VOC . This work attests that DTBT-based p-type polymers are ideal for the application in high-voltage OSCs.

The Green Box: Selenoviologen-Based Tetracationic Cyclophane for Electrochromism, Host–Guest Interactions, and Visible-Light Photocatalysis

The novel selenoviologen-based tetracationic cyclophanes (green boxes 3 and 5) with rigid electron-deficient cavities are synthesized via SN2 reactions in two steps. The green boxes exhibit good redox properties, narrow energy gaps, and strong absorption in the visible range (370-470 nm), especially for the green box 5 containing two selenoviologen (SeV2+) units. Meanwhile, the femtosecond transient absorption (fs-TA) reveals that the green boxes have a stabilized dicationic biradical, high efficiency of intramolecular charge transfer (ICT), and long-lived charge separation state due to the formation of cyclophane structure. Based on the excellent photophysical and redox properties, the green boxes are applied to electrochromic devices (ECDs) and visible-light-driven hydrogen production with a high H2 generation rate (34 μmol/h), turnover number (203), and apparent quantum yield (5.33 × 10-2). In addition, the host-guest recognitions are demonstrated between the green boxes and electron-rich guests (e.g., G1:1-naphthol and G2:platinum(II)-tethered naphthalene) in MeCN through C-H···π and π···π interactions. As a one-component system, the host-guest complexes of green box⊃G2 are successfully applied to visible-light photocatalytic hydrogen production due to the intramolecular electron transfer (IET) between platinum(II) of G2 and SeV2+ of the green box, which provides a simplified system for solar energy conversion.

A cellular automata framework for porous electrode reconstruction and reaction-diffusion simulation

Due to the high charge transfer efficiency compared to that of non-porous materials, porous electrodes with larger surface area and thinner solid pore walls have been widely applied in the lithium-ion battery field. Since the capacity and charge-discharge efficiency of batteries are closely related to the microstructure of porous materials, a conceptually simple and computationally efficient cellular automata (CA) framework is proposed to reconstruct the porous electrode structure and simulate the reaction-diffusion process under the irregular solid-liquid boundary in this work. This framework is consisted of an electrode generating model and a reaction-diffusion model. Electrode structures with specific geometric properties, i.e., porosity, surface area, size distribution, and eccentricity distribution can be constructed by the electrode generating model. The reaction-diffusion model is exemplified by solving the Fick’s diffusion problem and simulating the cyclic voltammetry (CV) process. The discharging process in the lithium-ion battery are simulated through combining the above two CA models, and the simulation results are consistent with the well-known pseudo-two-dimensional (P2D) model. In addition, a set of electrodes with different microstructures are constructed and their reaction efficiencies are evaluated. The results indicate that there is an optimum combination of porosity and particle size for discharge efficiency. This framework is a promising one for studying the effect of electrode microstructure on battery performance due to its fully synchronous computation way, easy handled boundary conditions, and free of convergence concerns.

Enhanced visible light catalytic activity of holey Ti3C2 based catalyst for azo dyes

The efficient degradation of organic dye pollutions is of great importance for environmental remediation. In this work, we prepared holey Ti3C2 (H-Ti3C2) and further synthesized H-Ti3C2/Ag/AgX (Cl, Br, I) Schottky catalysts by a simple electrostatic self-assembly method, and found that H-Ti3C2 could significantly improve the catalytic activity and stability of AgX. The H-Ti3C2/Ag/AgX composites showed great visible light absorption, obvious photocurrent intensity, and high charge transfer efficiency, ultimately improving photocatalytic efficacy for the degradation of methyl orange (MO) dye. The composite (5 wt%) H-Ti3C2/Ag/AgBr has the greatest photocatalytic activity, degrading 99.2% of the MO solution after 40 min of visible light irradiation, which is 1.08 and 2.02 times more than (5 wt%) Ti3C2 /Ag/AgBr and Ag/AgBr, respectively. The photocatalytic performance of H-Ti3C2/Ag/AgBr for MO dyes remains at 51% after five cycles. This result indicates that combining H-Ti3C2 with other photosensitive semiconductors to improve the catalytic activity and stability offers great possibilities. The present work not only provides a simplified method for the preparation of H-Ti3C2/Ag/AgX composites, but also offers a great possibility for H-Ti3C2 MXene as a co-catalyst to increase the photocatalytic degradation efficiency of organic pollutants.

Design of lateral and vertical Bi4O5I2/BiOCl heterojunctions with different charge migration pathway for efficient photoredox activity

As 2D heterojunction photocatalysts, lateral heterojunctions (LHs) formed based on chemical bonding generally exhibit much higher photocarrier separation efficiency than vertical heterojunctions (VHs) formed by van der Waals bonds. However, little is known about the different detailed interfacial structures and photocarrier separation mechanisms of the two heterojunctions. Herein, 2D BiOCl and Bi4O5I2 were selected as model building blocks to construct BiOCl/Bi4O5I2 VHs and LHs. The LHs with direct charge carrier transport channels show stronger interfacial electric field and higher charge transfer efficiency than the VHs. The photogenerated charge carrier migration pathway in the LHs follows a Z-scheme model, while the VHs fits a type II model. As a result, the BiOCl/Bi4O5I2 LHs exhibited higher redox performance than the VHs, which is 1.55, 1.56 and 2.1 times better for H2 production, Cr(VI) photoreduction and phenol photodegradation, respectively. This study demonstrates a new approach to constructing highly efficient facet-dependent 2D heterojunction photocatalysts.

Fast Fabrication of WS2/Bi2Se3 Heterostructures for High-Performance Photodetection.

Two-dimensional (2D) material heterostructures have attracted considerable attention owing to their interesting and novel physical properties, which expand the possibilities for future optoelectronic, photovoltaic, and nanoelectronic applications. A portable, fast, and deterministic transfer technique is highly needed for the fabrication of heterostructures. Herein, we report a fast half-wet poly(dimethylsiloxane) (PDMS) transfer process utilizing the change of adhesion energy with the help of micron-sized water droplets. Using this method, a vertical stacking of the WS2/Bi2Se3 heterostructure with a straddling band configuration is successfully assembled on a fluorophlogopite substrate. Thanks to the complementary band gaps and high efficiency of interfacial charge transfer, the photodetector based on the heterostructure exhibits a superior responsivity of 109.9 A W-1 for a visible incident light at 473 nm and 26.7 A W-1 for a 1064 nm near-infrared illumination. Such high photoresponsivity of the heterostructure demonstrates that our transfer method not only owns time efficiency but also ensures high quality of the heterointerface. Our study may open new pathways to the fast and massive fabrication of various vertical 2D heterostructures for applications in twistronics/valleytronics and other band engineering devices.

A BiVO4 Photoanode with a VOx Layer Bearing Oxygen Vacancies Offers Improved Charge Transfer and Oxygen Evolution Kinetics in Photoelectrochemical Water Splitting.

Sluggish oxygen evolution kinetics are one of the key limitations of bismuth vanadate (BiVO4 ) photoanodes for efficient photoelectrochemical (PEC) water splitting. To address this issue, we report a vanadium oxide (VOx ) with enriched oxygen vacancies conformally grown on BiVO4 photoanodes by a simple photo-assisted electrodeposition process. The optimized BiVO4 /VOx photoanode exhibits a photocurrent density of 6.29 mA cm-2 at 1.23 V versus the reversible hydrogen electrode under AM 1.5 G illumination, which is ca. 385 % as high as that of its pristine counterpart. A high charge-transfer efficiency of 96 % is achieved and stable PEC water splitting is realized, with a photocurrent retention rate of 88.3 % upon 40 h of testing. The excellent PEC performance is attributed to the presence of oxygen vacancies in VOx that forms undercoordinated sites, which strengthen the adsorption of water molecules onto the active sites and promote charge transfer during the oxygen evolution reaction. This work demonstrates the potential of vanadium-based catalysts for PEC water oxidation.

Influence of Pixel Design on Charge Transfer in Pinned Photodiode CMOS Image Sensors

The influence of pixel design on charge transfer, mainly on potential barrier and potential pocket, is investigated in this paper. By simplifying the interface region between the pinned photodiode (PPD) and the transfer gate (TG), an intuitive and simple method for analyzing the potential barrier and pocket is presented. Through TCAD simulations, the validity of the analysis method is verified, and the influence of some key dimension and process parameters in PPD pixel design on the potential barrier and pocket is clarified. The whole study help improve the understanding of the charge transfer limitation mechanism, and can achieve high charge transfer efficiency and low image lag noise in the PPD pixel design of CMOS image sensors (CISs).

Positioning hydrogen reaction sites by constructing CdS/CoNiMoS4 heterojunctions for efficient photocatalytic hydrogen evolution.

The high gravimetric energy density of hydrogen makes it an ideal chemical fuel to address the issues of fossil fuel depletion and environmental pollution. Even though transition metal sulfides (TMSs) have been extensively investigated as substitutes for noble metals, their effectiveness is still doubtful for practical applications. Herein, we introduce a facile and general strategy to fabricate heterojunctions with CdS nanorods and a multimetallic transition metal sulfide (CoNiMoS4) for enhanced photocatalytic activity. The CdS/CoNiMoS4 heterojunction will serve as a dual-function photocatalyst with enhanced visible light absorption capability offered by CdS and high charge transfer efficiency provided by CoNiMoS4 nanostructures. Moreover, CdS/CoNiMoS4 nanostructures exhibit the best photocatalytic performance to generate H2 with an amount of 31.9 mmol g-1 h-1, with a distinguished stability for over 25 h. This synthetic approach may offer a new strategy to create diverse heterojunctions with Earth-abundant multimetallic components, which may broaden their scope of application in catalysis.

Visible-light-enhanced photocatalytic activity of BaTiO3/γ-Al2O3 composite photocatalysts for photodegradation of tetracycline hydrochloride

A polyacrylamide gel method combined with low temperature sintering technology was developed for fabrication of BaTiO3/γ-Al2O3 composite photocatalysts, which exhibits excellent photocatalytic activity for the degradation of tetracycline hydrochloride (TC-HCl) under simulated sunlight irradiation. The effects of BaTiO3/γ-Al2O3 mass percentages, drug concentrations and pH values on the photocatalytic activity of BaTiO3/γ-Al2O3 composite photocatalysts were investigated. The optimum BaTiO3/γ-Al2O3 mass percentage, drug concentration and pH value are 5 wt%, 50 mg/L, and 6.77, respectively. The maximum photocatalytic degradation rate of BaTiO3/(5 wt%) γ-Al2O3 composite photocatalysts for the degradation of TC-HCl was approximately 16.81 times that of γ-Al2O3. The trapping experiments and reactive oxygen species production experiments proved that reactive hole and hydroxyl radical played major role in drug degradation. The photocatalytic activity enhancement of the BaTiO3/γ-Al2O3 composite photocatalysts came from the defect states in alumina and the interfacial defects between barium titanate and alumina and the high charge transfer and separation efficiency, which resulted from the type II band arrangement structure of BaTiO3/γ-Al2O3. The above results reveal that there is a significant potential application for the BaTiO3/γ-Al2O3 composite as a photocatalyst in the photo-degradation of drugs under simulated sunlight irradiation.

Interfacial charge transfer effects of α-Fe2O3/Cu2O heterojunction and enhancement mechanism of its photocatalytic oxidation

In order to construct Cu2O based heterostructures with high efficiency of interfacial charge transfer and clarify the enhancing mechanism of its photocatalytic performance for degrading antibiotics, and reveal the characteristics of band reconstruction and the photocatalytic reaction path, the α-Fe2O3/Cu2O heterojunction was established based on hydrothermal method. The crystal plane structure, morphological state, photoelectric conversion properties and photocatalytic degradation kinetics of α-Fe2O3/Cu2O heterojunction were revealed by XRD, XPS, UV-Vis, BET, SEM, TEM and RSM, and the reconstruction principles of bandgap formations of heterojunction were analyzed by the density function theory. The reaction intermediates of levofloxacin were distinguished with HPLC-MS/Ms, and the reactive sites and photocatalytic oxidation paths of levofloxacin were clarified from the frontier electron density calculation. It turned out that the constructed α-Fe2O3/Cu2O heterojunction emerged high energy (111) preferred crystal plane orientation and significantly enhanced the specific surface area and visible spectral excitation efficiency. The micromorphologies of Cu2O, M1-Cu2O, M2-Cu2O and M3-Cu2O crystals were cube, irregular polyhedron and approximate sphere, respectively. The introduction of Fe 3d hybrid orbital in α-Fe2O3/Cu2O heterojunction widened the band gap of Cu2O microcrystals, resulting in the migration of spectral absorption edging to high energy level and causing blueshift. Photogenerated superoxide radicals and hydroxyl radicals were the dominant active species for photocatalytic oxidation of levofloxacin. The removal rate of levofloxacin by α-Fe2O3/Cu2O heterojunction could still reach more than 70% after eight cycles and show high material durability. The ring opening reaction process and decarboxylic reaction of quinolone group and piperazine side chain were the main pathways for photocatalytic oxidation of levofloxacin. This study systematically revealed the interfacial charge transfer characteristics and photocatalytic reaction mechanism of α-Fe2O3/Cu2O heterojunction.

Triboelectric nanogenerator with enhanced output and durability based on Si-DLC films

As one of the working modes of triboelectric nanogenerators (TENGs), the sliding-mode TENG has a higher charge-transfer efficiency than the contact-separation mode. However, the durability and stability of these devices remain challenging for practical applications because most dielectric materials for TENGs are organic polymers. This study used Si-incorporated diamond-like carbon (Si-DLC) films as non-polymer dielectric materials for sliding-TENGs to improve output and durability. Si-DLC films with varying Si contents were prepared using plasma-based ion implantation and deposition, and their triboelectric and tribological properties were investigated. The Si-DLC film with a higher Si content exhibited a higher triboelectric output under dry conditions owing to its stronger electron-donating ability. Furthermore, it was found that the output and durability of the Si-DLC-based sliding-TENG can be further enhanced under unsubmerged water-lubricated conditions compared with those under dry conditions. This enhanced output is attributed to the more electropositive nature of water compared with that of the Si-DLC films. Moreover, the enhanced durability and stability of the Si-DLC-based TENG under water-lubricated conditions are attributed to the anti-abrasion properties of the Si-DLC films, which prevent the formation of a transferred PTFE layer on the Si-DLC surface. This research proposed an integrated strategy to enhance output and durability simultaneously, showing great potential for designing durable self-driving sensing systems in machinery.

Tracking the pyrolysis process from 2D Mn2n polymer to high-rate anode materials for lithium ion batteries

By manipulating the pyrolysis of multidimensional precursors, excellent energy storage materials can be obtained. On the molecular level, however, the pyrolysis tracking and evolution of two-dimensional (2D) precursors require additional study. Here, we designed a 2D layered Mn-based polymer (Mn2n, [Mn2L2(CH3OH)2]n, L = 3-ethoxylsalicylate iso-nicotinyl hydrazone) bridged with L as a precursor, and obtained a 2D porous nanosheet N-doped carbon skeleton embedded with Mn2+O (Mn2+O/NC) through controlled pyrolysis under an inert atmosphere. The pyridine nitrogen coordination of isoniazid is astonishingly essential for the formation of 2D layered Mn2n polymers. The formation of Mn-N(pyridine) bonds serves as a bridge between the basic units of Mn2. Thermogravimetric mass spectrometry (TG-MS) could track the pyrolysis process and provide a potential evolutionary from a 2D Mn2n precursor to a 2D porous nanosheet Mn2+O/NC structure. The specific capacity of Mn2+O/NC-800 electrode reaches up to 614.1 mAh g−1 after 600 cycles at 200 mA g−1 current density when the pyrolysis product is used as the anode material of lithium ion battery. Dynamic analysis indicates that the 2D porous nanosheet structure of Mn2+O/NC has a high pseudocapacitance contribution and charge transfer efficiency, which effectively improves the performance of lithium ion batteries. This work will provide a useful guidance for the design of new electrode materials.

Hetero-structured NiMoO4/Ni3S4/MoS2 pompons decorated nickel foam electrode for high-efficient urea and urine electrolysis

In search of efficient electrolytic materials for hydrogen fuel production while realizing sewage denitrification, a unique heterostructure composed of the NiMoO4, Ni3S4 and MoS2 phases with multiple interfaces was grown on nickel foam (NF) by vulcanizing the NiMoO4 precursor. The obtained NF/NiMoO4-S possesses pompon-like morphology and abundant pores, significantly different from its precursor. Precisely due to this multi-phase, multi-interface, and highly opened porous structure, NF/NiMoO4-S exhibits outstanding electrochemical performance in terms of superior activity and selectivity, appropriate kinetics, high charge transfer efficiency and robust durability. In urea media, NF/NiMoO4-S requires a low HER overpotential of 73 mV (10 mA cm−2) and a small potential of 1.382 V for UOR (50 mA cm−2) respectively. When assembled into a whole-cell electrolyzer, the voltage (50 mA cm−2) is 1.55 V, much lower than that of water electrolyzer. Attractively, in the human-urine medium, no significant activity degradation was observed on NF/NiMoO4-S. Experiments have also demonstrated an excellent durability of the obtained NF/NiMoO4-S catalyst either in urea or urine condition. This work provides a simple and energy-saving idea for the design and preparation of practical urea electrolytic materials.

Facile preparation and modification of SrTiO3 through Ni–Cd co-doping as an efficient visible-light-driven photocatalyst

Visible light-driven Ni–Cd co-doped SrTiO3 photocatalyst was prepared through a co-precipitation technique. The influence of various amounts of doped elements on the properties of the pure SrTiO3 phase has been explored. The characterization was performed employing the X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman, X-ray photoelectron spectroscopy (XPS), field emission-scanning electron microscopy (FESEM), UV–visible diffuse reflectance spectroscopy (DRS), photoluminescence (PL), electrochemical impedance spectroscopy (EIS), and transient photocurrent experiments. By Ni–Cd co-doping, the average particle size was reduced from 100 to 65 nm, the band gap value was lowered from 3.2 to 2.78 eV, and the powder's surface area was increased by about 2.3 times compared with the pure phase. Low PL peak intensity, small EIS radius, and higher photocurrent density of the 5 wt% doped sample indicate higher charge transfer efficiency than the pure sample. The effect of different photocatalytic experiment parameters on the photodegradation performance has been studied. In this regard, a 60-min visible light irradiation time, 1 g mL−1 initial dye concentration, and 0.7 g L−1 powder dosage were found to be the best values. After 60 min of visible light irradiation, doped SrTiO3 with 5 wt% Ni–Cd thoroughly degraded methylene blue (MB) dye. Additionally, the superoxide radical and holes also play a significant role in photodegradation as determined by the scavenger trapping test. Compared with MB, the prepared sample demonstrated less degradation ability for methyl orange (MO) and Rhodamine-B (RhB) dyes.

Facile synthesis of multitasking composite of Silver nanoparticle with Zinc oxide for 4-nitrophenol reduction, photocatalytic hydrogen production, and 4-chlorophenol degradation

The multifunctional zinc oxide electrode was used in numerous applications. This study includes the catalytic performance of zinc oxide, which is further enhanced by the silver nanoparticle. The facile and cost-effective hydrothermal method is used to fabricate ZnO and Ag/ZnO composites. The Ag/ZnO-based catalyst is mainly constructed to reduce the water pollution caused by industrial discharges, which contains hazardous compounds like 4-nitrophenol (4-NP), 4-chlorophenol (4-CP), and many other organic compounds. Removal of these hazardous organic compounds from potable water sources is essential for both ecosystem and human beings. In this study, Ag/ZnO composite was used as an efficient catalyst for catalytic reduction of hazardous 4-NP, and photocatalytic degradation of 4-CP. Catalytic reduction of the 4-NP using the Ag/ZnO composite is based on the Langmuir–Hinshelwood principle. In addition to this study Ag/ZnO composite was tested for photocatalytic hydrogen production. The high charge transfer efficiency of Ag in the Ag/ZnO composite is helpful for enhancement in catalytic performance for hydrogen production and 4-CP degradation. The catalytic activity of Ag/ZnO in the 4-CP degradation increased from 59% to 96% and for hydrogen production rate increased from 1.9 to 12 µmol h− 1, as compared with the catalytic activity of ZnO.