- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Unassisted Water Splitting Using Standard Silicon Solar Cells Stabilized with Copper and Bi-functional NiFe Electrocatalysts
摘要： Silicon photovoltaic cells functionalized with water splitting electro-catalysts are promising candidates for unassisted water splitting. In these devices, the total surface of silicon solar cell is covered with electrocatalyst causing issues with i) stabilizing silicon solar cell in water and ii) device efficiency due to parasitic optical absorption in electrocatalyst. We describe and validate a water splitting device concept using a crystalline silicon solar cell where the front-side is covered with insulating Si3N5 antireflection coating. The Ag contacts, fired through the antireflection coating, are removed and subsequently substituted with NiFe layered double hydroxide (LDH) or Cu/NiFe-LDH electrocatlysts. In this device only the site of Ag contacts, nearly 2% of total device area is covered by the electrocatalyst. We found this small area of catalyst does not limit device performance and addition of a Cu interlayer between Si and NiFe-LDH improves device performance and stability. The unassisted water splitting efficiency of 11.31%, measured without separating the evolved gases, is achieved using a device composed of three series-connected silicon solar cells and a NiFe-LDH/Cu/Ni-foam counter electrode in a highly alkaline electrolyte.
关键词： NiFe layered double hydroxides,Photoelectrochemical Cells,Unassisted Water Splitting,Crystalline Silicon Solar Cell,Si Photocathodes
更新于2025-09-23 15:19:57
-
Transparent Ta3N5 Photoanodes for Efficient Oxygen Evolution toward the Development of Tandem Cells
摘要： Photoelectrochemical water splitting is regarded as a promising approach to the production of hydrogen, and the development of efficient photoelectrodes is one aspect of realizing practical systems. In this work, transparent Ta3N5 photoanodes were fabricated on n-type GaN/sapphire substrates to promote O2 evolution in tandem with a photocathode, to realize overall water splitting. Following the incorporation of an underlying GaN layer, a photocurrent of 6.3 mA cm-2 was achieved at 1.23 V vs. a reversible hydrogen electrode. The transparency of Ta3N5 to wavelengths longer than 600 nm allowed incoming solar light to be transmitted to a CuInSe2 (CIS), which absorbs up to 1100 nm. A stand-alone tandem cell with a serially-connected dual-CIS unit terminated with a Pt/Ni electrode was thus constructed for H2 evolution. This tandem cell exhibited a solar-to-hydrogen energy conversion efficiency greater than 7% at the initial stage of the reaction.
关键词： (oxy)nitrides,photoelectrochemistry,water splitting,photoelectrochemical tandem cell,solar energy conversion
更新于2025-09-23 15:19:57
-
Two-dimensional Janus PtSSe for photocatalytic water splitting under the visible or infrared light
摘要： Recently, two-dimensional Janus materials have attracted increasing research interest due to their particular structure and great potential in electronics, optoelectronics and piezoelectronics. Here, we propose 2D Janus PtSSe with compelling photocatalytic properties which were investigated by means of first-principles calculations. 2D Janus PtSSe exhibits high thermal, dynamic and mechanical stability. Most remarkably, single-layer PtSSe exhibits an indirect band gap of 2.19 eV, high absorption coefficients in the visible light region, appropriate band edge positions and strong ability for carrier separation and transfer, thus rendering it a promising candidate for photocatalytic water splitting. Moreover, double-layer PtSSe compounds with different stacking configurations are extraordinary photocatalysts for water splitting even under infrared light, owing to their small band gaps as well as the built-in electrical field. Our results reveal 2D PtSSe with high experimental feasibility as a new platform for the overall water splitting reaction.
关键词： two-dimensional Janus materials,first-principles calculations,photocatalytic water splitting,visible light,infrared light
更新于2025-09-23 15:19:57
-
Structural transformation identification of sputtered amorphous MoS <sub/>x</sub> as efficient hydrogen evolving catalyst during electrochemical activation
摘要： Molybdenum sulfide MoSx is considered as attractive hydrogen evolution catalyst since it is free of noble metals and shows a low overpotential. Especially, amorphous molybdenum sulfide has attracted attention because of its high catalytic activity. However, the catalytic mechanism of the hydrogen evolution reaction is not yet fully understood. Therefore in our study, layers of MoSx were deposited by reactive magnetron sputtering varying the substrate temperature in the range from room temperature (RT) to 500°C. The morphology and structure of the films change significantly as a function of temperature, from an amorphous to a highly textured 2H-MoS2 phase. The highest catalytic activity was found for amorphous layers deposited at RT showing an overvoltage of 180 mV at a current density of -10 mAcm-2 in a 0.5 M sulfuric acid electrolyte (pH 0.3) after electrochemical activation. As detected by Raman spectroscopy the RT deposited catalyst consists of [Mo3S13]2- and [Mo3S12]2- entities which are interconnected via [S2]2- and S2- ligands. When sweeping the potential from 0.2 to -0.3 V vs RHE a massive release of sulfur in form of gaseous H2S was observed in the first minutes as detected by differential electrochemical mass spectroscopy (DEMS). After electrochemical cycling for 10 min, the chains of these clusters transform into a layer-type MoS2-x phase observed by in-situ Raman spectroscopy. In this transformation process, H2S formation gradually vanishes and H2 evolution becomes dominant. The transformed phase is considered as a sulfur deficient molybdenum sulfide characterized by a high number of molybdenum atoms located at the edges of nano-sized MoSx islands, which act as catalytically active centers.
关键词： hydrogen evolving catalyst,structural transformation,water splitting,molybdenum sulfide,sputtering
更新于2025-09-19 17:15:36
-
C-doping into h-BN at low annealing temperature by alkaline earth metal borate for photoredox activity
摘要： BCN (boron carbon nitride) nanosheets are promising photocatalyst materials for solar fuel production by visible light-driven water splitting and CO2 reduction due to their tunable band gap and unique properties. C-doping into h-BN by thermal annealing makes possible the preparation of BCN nanosheets with photocatalytic activity under visible light irradiation, but it generally requires a very high temperature (>1250 °C) from the thermodynamic viewpoint. Here, we report a new method to prepare BCN nanosheets with visible light-photocatalytic activity at lower annealing temperature (1000 °C) than equilibrium by adding alkaline earth metal compounds. BCN nanosheets formed in borate melt show a clear layered structure, tunable bandgap and photocatalytic activity for water splitting and CO2 reduction under visible light illumination. This provides a direction for doping other elements into h-BN at low annealing temperature by alkaline earth metal borates.
关键词： h-BN,low annealing temperature,BCN nanosheets,water splitting,CO2 reduction,C-doping,photoredox activity,alkaline earth metal borate
更新于2025-09-19 17:15:36
-
Facile Coengineering of Oxygen Defects and Highly Active {110} Facets in TiO <sub/>2</sub> Nanorods for Efficient Water Splitting
摘要： Optimizing the photocatalytic activity of TiO2 for hydrogen evolution from water splitting remains a challenging task. Herein, we report the synthesis of a slightly oxygen-deficient TiO2 film consisting of anatase nanorods with mainly {110} lateral surfaces by a facile one-step technology of magnetron sputtering. The 1D nanostructure and Ti3+/oxygen vacancies in the as-prepared TiO2 film are advantageous for the inhibition of recombination of electron-hole pairs, while the exposed {110} lateral surfaces provide abundant surface active sites; as a result, this TiO2 exhibited an ultra-high photocatalytic activity for water splitting. Remarkably, photocatalytic overall water splitting into H2 and O2 simultaneously with a ratio close to 2:1 has been realized for the first time over pristine anatase TiO2 without the assistance of sacrificial electron donor and cocatalyst. Additionally, in the presence of methanol as a sacrificial agent, the pristine TiO2 displayed a high apparent quantum efficiency of ～21.4% at 365 nm and the hydrogen generation rate under the full-arc light irradiation could be as high as 14.35 mmol m-2 h-1, which is about three orders of magnitude higher than that of P25 film (~0.014 mmol m-2 h-1). This result provides a facile pathway to synthesizing defect-based metal oxide with optimal facets and morphology for high-efficiency energy conversion.
关键词： TiO2 nanorods,active facets,photocatalysis,oxygen defect,water splitting
更新于2025-09-19 17:15:36
-
Recent progresses in the design of BiVO4-based photocatalysts for efficient solar water splitting
摘要： Photocatalysis and photoelectrocatalysis are both considered as promising routes to solve energy and environmental crises. Particularly, photoelectrochemical (PEC) water splitting has been extensively studied in the search for sustainable ways of converting solar energy into chemical energy to produce energy-dense fuel with minimal carbon footprint. Bismuth vanadate (BiVO4) has attracted a lot attention in recent years due to its visible-light activity, favorable conduction and valence band edge positions, and low-cost facile synthesis route. However, BiVO4 still suffers from low carrier separation efficiency and slow oxygen evolution kinetics on its surface. To overcome these weaknesses, various modification strategies, including nanostructural morphology control, element doping, heterostructures (particularly Z-scheme), plasmonic enhancement and surface passivation, have been proposed and implemented to improve its PEC activity. This short review summarizes the most recent advances on the designs of BiVO4-based photocatalysts and photoanodes. Some of the best-performing BiVO4–based photo-electrode structures to date are demonstrated, and the critical parameters that contribute to these outstanding performances are discussed.
关键词： Solar energy harvesting,BiVO4,Photocatalyst,Photoelectrochemical water splitting
更新于2025-09-19 17:15:36
-
Significant enhancement of stability for visible photocatalytic overall water splitting by assembling ultra-thin layer of NiO over Zn1-xCdxSX
摘要： Solar light driven water splitting into hydrogen and oxygen using visible light active photocatalyst has been considered as a clean, green, and renewable route to solar energy conversion and storage. Although Zn1-xCdxS catalyst shows comparatively higher activity for photocatalytic hydrogen generation under visible light irradiation, it suffers serious photocorrosion during the photocatalytic reaction. Deposition of protection layer over Zn1-xCdxS catalyst is believed to be an effective way to inhibit such photocorrosion. Nevertheless, seldom of protection layer exhibits satisfied catalytic properties for hydrogen evolution while presents good protection ability. In this work, a new Zn1-xCdxS photocatalyst has been developed for water splitting under visible light illumination by assembled an ultra-thin NiO layer over Zn0.8Cd0.2S via in-situ photodeposition method. By this strategy, NiO/Zn0.8Cd0.2S showed significant higher activity than Pt/Zn0.8Cd0.2S under same conditions without photocorrosion. The AQE of 0.66% for hydrogen evolution at 430 nm has been achieved and multi-cycle stability has been accomplished up to 12 hours without significant decay. Moreover, the strong electronic coupling between NiO layer and Zn1-xCdxS promoted efficient charge separation and migration.
关键词： Overall water splitting,sulfide semiconductor photocatalyst with thin NiO catalytic layer,enhanced charge separation and migration,significant enhanced stability,anti-photocorrosion
更新于2025-09-19 17:15:36
-
Annealing Induced Oxygen Defects on Green Sonochemically Synthesized ZnO Nanoparticles for Photoelectrochemical Water Splitting
摘要： Zinc oxide (ZnO) nanoparticles were prepared by a green process using a simple sonochemical method. The prepared nanoparticles were annealed at different annealing temperatures in order to determine the role of the annealing temperature on the structural, morphological and optical properties of the prepared material. The defects related photoluminescence properties of the ZnO nanoparticles are discussed in detail. X-ray photoelectron spectroscopy provided the information regarding the presence of the defects in the material. ZnO emission related to defect emission was observed to increase with annealing temperature upto 600°C and then decreased. These defects played a crucial role in the performance of the photo-electrochemical (PEC) activity. The PEC performance has increased with an increase in the amount of oxygen related defects present in the material due to annealing.
关键词： PEC water splitting,Defects,XPS,Green chemistry,ZnO
更新于2025-09-19 17:15:36
-
TiO2 nanotube arrays modified with nanoparticles of platinum group metals (Pt, Pd, Ru): enhancement on photoelectrochemical performance
摘要： Highly ordered TiO2 nanotube arrays (TiO2 NTs) were synthesized by anodization method using a titanium foil and further modified with nanoparticles (? = 2~10 nm) of three platinum group metals (that is, platinum, palladium, and ruthenium) through potentiostatic pulsed electrodeposition method to obtain the composite material. Compared with pure TiO2 NTs, all the three composite samples (M-TiO2 NTs, M = Pt, Pd, Ru) showed different enhancement effects on the light responses, as well as different photoelectrochemical performances. In this study, the performance of M-TiO2 NTs, which worked as photoanode and cathode, was investigated. Ru-TiO2 exhibited the best degradation yield (~ 85.8%) when applied as photoanode under visible light illumination, which indicated the platinum group metal could also be induced under visible irradiation, not just served as the co-catalyst. M-TiO2 NTs as cathode were evaluated under the hydrogen evolution reaction (HER). The three M-TiO2 NT electrodes showed an improved efficiency over pure TiO2 NTs, while Pt-TiO2 NTs performed even better (without any sacrificial agent) with higher Faradic efficiency than platinum electrode in the photoelectrocatalytic hydrogen production, which could be explained by the uniform and fine metal nanoparticles on the surface of TiO2 NTs to offer abundant active sites for the reaction.
关键词： Platinum group metal nanoparticles,Photoelectrocatalysis,Water splitting,Hydrogen production,TiO2 nanotube arrays
更新于2025-09-19 17:15:36