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Dynamically Optimized Multi-Interface Novel BiSI-Promoted Redox Sites Spatially Separated N-p-n Double Heterojunctions BiSI/MoS2/CdS for Hydrogen Evolution
摘要： Novel BiSI promoted n-p-n double heterojunctions multi-interface photocatalyst BiSI/MoS2/CdS was constructed. BiSI is applied to photocatalytic hydrogen evolution. It possesses a small band gap and a strong optical absorption coefficient, therefore, the optical absorption scope and coefficient of MoS2/CdS have been effectively enhanced by compounding with BiSI. The continuous heterojunctions strengthened the function of single junction and guided the carriers’ transfer direction, thus the redox reactions occur at spatially separated sites. Built-in electric field along the radial direction of BiSI nanorod and MoS2 interlayer helps to transport carriers within lifetime. Carrier dynamics is optimized by multi-interface structure. In general, a new material BiSI is introduced to construct a multi-interface structure to optimize carrier dynamics, which resulted in a 46-fold increase in hydrogen production efficiency.
关键词： multi-interface,dynamics optimization,enhanced optical absorption,photocatalytic water splitting,n-p-n continuous heterojunctions,BiSI
更新于2025-11-14 15:29:11
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Photoelectrochemical enhancement from deposition of BiVO4 photosensitizer on different thickness layer TiO2 photoanode for water splitting application
摘要： TiO2 is a prominent photocatalyst and has been pioneering the research in water splitting for hydrogen cell production. However, TiO2 has low visible region absorption which limit its functionality as a photoabsorber and requires addition of other high absorptive material such as BiVO4. Fabrication of TiO2 photoanode on FTO substrate and deposition of BiVO4 on TiO2 were done using simple spin coating procedure. TiO2/BiVO4 photoelectrode were first tested for its photo absorption, photocurrent generation and electrical impedance to obtain the optimized sample. Optimized sample then further tested for its photocurrent generation stability using linear sweep voltammetry and time dependent photocurrent test. Photo absorption enhancement from TiO2/BiVO4 of almost 10 folds achieved along the visible region comparing to pure TiO2. Photogenerated charge produced from TiO2/BiVO4 is also 3 folds higher compared to pure TiO2at water oxidation threshold potential at 1.23 V vs. RHE. From photocurrent generation analysis, heterostructure of TiO2/BiVO4 proven to produce more than 3 folds higher photocurrent comparing to both pure TiO2 and BiVO4.
关键词： Z-scheme,Bismuth vanadate,Thin-film,Titanium dioxide,Photoelectrochemical water splitting
更新于2025-11-14 15:19:41
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Synthesis of novel Mn-doped Fe2O3 nanocube supported g-C3N4 photocatalyst for overall visible-light driven water splitting
摘要： A novel Mn-doped Fe2O3 modified g-C3N4 nanosheets composite has been prepared for overall water splitting. Structure characterizations reveal that the Mn are successfully doped in the Fe2O3 nanoparticle and a close interface between g-C3N4 and Mn-doped Fe2O3is obtained. The optimized FMC-10 photocatalyst has a H2 evolution of 51 μmol h?1. The improved photocatalytic performance can be ascribed to the synergy effect of both Mn-doped Fe2O3and g-C3N4. Doping Fe2O3 with Mn promotes photo-induced charges and increases the charge transfer for the improved conductivity of the bulk Fe2O3, while favorable contacting with g-C3N4 enhances the charge separation ability.
关键词： Mn doped,Pure water splitting,g-C3N4,Fe2O3
更新于2025-11-14 15:15:56
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High Temperature One-Step Synthesis of Efficient Nanostructured BiVO4 Photoanodes for Water Oxidation
摘要： Bismuth vanadate (BiVO4) is a promising photoanode material for photoelectrochemical water splitting due to its well-suited valence band edge and comparatively narrow band gap. Herein, we provide first insights on the high temperature rapid and scalable synthesis of efficient nanostructured BiVO4 photoanodes for water oxidation. Nanostructured BiVO4 films with tunable optical density and porosity from 12 to 80% have been synthesized in few seconds by direct deposition of flame-made BiVO4 nanoparticle aerosols. The impact of BiVO4 film structural properties on the photooxidation performance has been systematically investigated by a set of electrochemical and physical characterizations indicating key directions for its morphological optimization. It was found that the BiVO4 water oxidization performance is mainly determined by two competitive factors, viz. accessible surface area and carrier conductivity through the grain boundaries. Optimization of these two factors increased the photocurrent densities by more than 3 times resulting in ca 1.5 mA cm-2 for sulphite oxidation and ca 1 mA cm-2 for water oxidation with a FeOOH\NiOOH co-catalyst at 1.0 V vs. the reversible hydrogen electrode (VRHE) under simulated one sun illumination. These findings provide novel insights into the structure-activity relationships of high temperature synthesized BiVO4 photoanodes for solar-powered water splitting, and introduce a scalable and low-cost approach for their rapid nanofabrication.
关键词： Flame Synthesis,Bismuth Vanadate,Scalable,One-Step,Photoelectrochemical Water Splitting
更新于2025-10-22 19:40:53
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Plasmonic nickel nanoparticles decorated on to LaFeO3 photocathode for enhanced solar hydrogen generation
摘要： Plasmonic Ni nanoparticles were incorporated into LaFeO3 photocathode (LFO-Ni) to excite the surface plasmon resonances (SPR) for enhanced light harvesting for enhancing the photoelectrochemical (PEC) hydrogen evolution reaction. The nanostructured LFO photocathode was prepared by spray pyrolysis method and Ni nanoparticles were incorporated on to the photocathode by spin coating technique. The LFO-Ni photocathode demonstrated strong optical absorption and higher current density where the untreated LFO film exhibited a maximum photocurrent of 0.036 mA/cm2 at 0.6 V vs RHE, and when incorporating 2.84 mmol Ni nanoparticles the photocurrent density reached a maximum of 0.066 mA/cm2 at 0.6 V vs RHE due to the SPR effect. This subsequently led to enhanced hydrogen production, where more than double (2.64 times) the amount of hydrogen was generated compared to the untreated LFO photocathode. Ni nanoparticles were modelled using Finite Difference Time Domain (FDTD) analysis and the results showed optimal particle size in the range of 70e100 nm for Surface Plasmon Resonance (SPR) enhancement.
关键词： LaFeO3,Finite difference time domain,Surface plasmon resonance,Ni nanoparticle,Photocathode,Photoelectrochemical water splitting
更新于2025-10-22 19:40:53
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Gold doping induced strong enhancement of carbon quantum dots fluorescence and oxygen evolution reaction catalytic activity of amorphous cobalt hydroxide
摘要： Gold doping induced strong enhancement of carbon quantum dots fluorescence and oxygen evolution reaction catalytic activity of amorphous cobalt hydroxide. Water splitting using electrocatalysts is expected to provide an alternative green energy source to meet increasing energy demands as well as addressing environmental concerns related to fossil fuels. Herein, we report one-step synthesis of sulfur, nitrogen and Au-doped carbon quantum dots (Au-SCQDs) and strong enhancement of fluorescence intensity and oxygen evolution reaction (OER) catalytic activity of amorphous Co(OH)2 nanoparticles compared to pure Co(OH)2 as well as commercial RuO2 and Pt/C catalysts. Au doping into sulfur and nitrogen co-doped CQDs showed over seventy times enhanced fluorescence. OER studies of amorphous-Co(OH)2 incorporated Au-SCQDs produced current density of 178 mA cm?2 at the applied potential of 2.07 V whereas un-doped Co(OH)2 showed current density of 59 mA cm?2. To produce geometric current density of 10 mA cm?2, amorphous Co(OH)2-Au-SCQDs (CSA) required 388–456 mV overpotential depending on the Au ion concentration used for preparing the Au-SCQDs, which is equal to or lower than overpotential required by commercial electrocatalysts. The strongly enhanced OER activity of Co(OH)2-Au-SCQDs (CSA) was attributed to the presence of electronegative metallic conducting Au atoms along with the high catalytic surface area of amorphous Co(OH)2. The present studies demonstrate a new method of exploiting amorphous Co(OH)2NPs electrocatalysts that could provide more catalytically active sites by integrating an electronegative conducting Au atom doped SCQDs matrix.
关键词： amorphous cobalt hydroxide,fluorescence,water splitting,Gold doping,carbon quantum dots,oxygen evolution reaction,electrocatalysts
更新于2025-10-22 19:40:53
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Surface-to-volume ratio drives photoelelectron injection from nanoscale gold into electrolyte
摘要： Hot charge carriers from plasmonic nanomaterials currently receive increased attention due to their promising potential in important applications such as solar water splitting. While a number of important contributions were made on plasmonic charge carrier generation and their transfer into the metal’s surrounding in the last decades, the local origin of those carriers is still unclear. With our study employing a nanoscaled bicontinous network of nanoporous gold, we take a comprehensive look at both subtopics in one approach and give unprecedented insights into the physical mechanisms controlling the broadband optical absorption and the generation and injection of hot electrons into an adjacent electrolyte where they enhance electrocatalytic hydrogen evolution. This absorption behavior is very different from the well-known localized surface plasmon resonance effects observed in metallic nanoparticles. For small ligament sizes the plasmon decay in our network is strongly enhanced via surface collisions of electrons. These surface collisions are responsible for the energy transfer to the carriers, thus, the creation of hot electrons from a broad spectrum of photon energies. As we reduce the gold ligament sizes below 30 nm, we demonstrate an occurring transition from absorption that is purely exciting 5d-electrons from deep below the Fermi level to an absorption which significantly excites “free” 6sp-electrons to be emitted. We differentiate these processes via assessing the internal quantum efficiency of the gold network photoelectrode as a function of the feature size providing a size-dependent understanding of the hot electron generation and injection processes in nanoscale plasmonic systems. We demonstrate that the surface effect - compared to the volume effect – becomes dominant and leads to significantly improved efficiencies. The most important fact to recognize is that in the surface photoeffect presented here, absorption and electron transfer are both part of the same quantum mechanical event.
关键词： Hot electron,Photoemission,Water splitting,Hydrogen evolution,Carrier injection,Surface damping,Nanoporous Au
更新于2025-10-22 19:40:53
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H2 production by the water splitting reaction using photocatalysts derived from calcined ZnAl LDH
摘要： Photocatalysts based on calcined ZnAl layered double hydroxides were obtained by coprecipitation and the subsequent thermal treatments at different temperatures. The calcined materials were characterized and its photocatalytic behavior was evaluated in the water splitting reaction in presence of UV irradiation. According to the XRD analysis, there was detected the presence of Zn as hexagonal ZnO in all the samples, as well as Al forming ZnAl2O4 and Zn6Al2O9, depending on the temperature of calcination employed. H2 yield was higher as the annealing temperature was increased due to the formation of the heterojunctions of ZnO with the Zn6Al2O9 and ZnAl2O4 oxides, reaching the maximum value in the sample annealed at 600 °C. Some decay in the activity was observed in the sample calcined at 700 °C, probably due to the higher recombination rate of the photo-generated charge carriers in that heterojunction in comparison with that obtained at 600 °C.
关键词： Hydrogen,Calcined LDH,ZnAl mixed oxides,Photocatalyst,Heterojunction,Water splitting
更新于2025-09-23 15:23:52
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Ti3C2 MXene nanoparticles modified metal oxide composites for enhanced photoelectrochemical water splitting
摘要： MXene, an emerging family of two-dimensional (2-D) material, has shown outstanding electronic properties and promise for the applications on energy storage and conversion. In this paper, Ti3C2 MXene nanoparticles were synthesized by a facile solvent exfoliation method and used to construct metal oxide/Ti3C2 heterostructures. When these heterostructures were used as photoanodes for photoelectrochemical water splitting, significantly improved photoactivity and stability were achieved. Compared to pristine TiO2, 6-fold enhanced applied bias photon-to-current efficiency (ABPE) was achieved for TiO2/Ti3C2 heterostructures. According to the electron spin resonance, electrical impedance spectroscopic and Mott-Schottky measurements, the enhanced photoelectrochemical performance was ascribed to the presence of Ti3C2 as oxygen evolution cocatalysts and the strong interfacial interactions between metal oxide and Ti3C2. Therefore, our research provides a new way to design MXene-based heterostructures for solar energy conversion applications.
关键词： Metal oxide,MXene,Heterostructured photoanodes,Photoelectrochemical,Water splitting
更新于2025-09-23 15:23:52
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Aging of a Vanadium Precursor Solution: Influencing Material Properties and Photoelectrochemical Water Oxidation Performance of Solution-Processed BiVO <sub/>4</sub> Photoanodes
摘要： Metal–organic decomposition is an easy way to fabricate BiVO4 (BVO) photoanodes; however, it often experiences a reproducibility issue. Here, the aging duration of a vanadium precursor solution, vanadyl acetylacetonate in methanol, is identified as a factor that profoundly affects reproducibility. Substantial changes in structural, optical, and electrical properties of BVO films are observed upon varying aging time of vanadium precursor solutions, which subsequently impacts photoelectrochemical (PEC) water oxidation and sulfite oxidation reactions. With the optimum number of aging days (3 d), some deficiency of oxygen is observed, which is accompanied by an increase in carrier concentration and a reduced charge transfer resistance in the PEC device, which produces the highest PEC performance that is comparable to the state-of-the-art undoped BVO photoanodes. The findings point to the importance of understanding solution chemistry and demonstrate that utilization of the understanding of fine adjustment of the composition of BVO films can produce highly reproducible and efficient BiVO4 photoanodes.
关键词： solution aging,metal–organic decomposition,bismuth vanadate,chemical composition,photoelectrochemical water splitting
更新于2025-09-23 15:23:52