Research On The Preparation And Photoelectrichemical Water Splitting Performance Of CuW_1-xMo_xO₄ Photoanodes

Accompanied by social development is the excessive consumption of energy by human beings,at the same time,the energy consumption structure based on fossil energy brings serious environmental pollution problems.In order to deal with these two problems,developing renewable energy is an imperative way.In much renewable energy,hydrogen energy has gained much attention because of its high energy density and clean combustion products.Hydrogen production by photoelectrochemical water splitting is a cheap,efficient and environmentally friendly way with good prospects and huge potential as well as is expected to be widely applied.However,due to the limitation of photoanodes,photoelectrochemical water splitting systems are still far from practical application.The optical absorption range of the photoanode material determines the theoretical maximum solar conversion efficiency of the photoanode,so when selecting the photoanode material,it is important to select a narrow bandgap,semiconductor material with visible light response.Then on its basis,the bulk carrier separation efficiency and surface reaction efficiency of the photoanodes are continuously improved to maximize the performance of the photoanodes.As a photoanode material with a narrow band gap,CuW1-xMOxO4 has a solar energy conversion efficiency of up to 17.8%,which has good application potential.However,there are very few studies on CuW1-xMoxO4 photoanodes,and the actual performance is still far from the theoretical value,which deserves further exploration.In this paper,the multi-metal oxide semiconductor CuW1-xMoxO4 was used as the research object.CUW1-xMoxO4 photoanodes were prepared by two different methods and their performance of photoelectrochemical water splitting were studied.The main research contents are as follows:Research on Preparation and Photoelectrochemical Water Splitting Performance of CuW1-xMoxO4 Granular Film Photoanode.In this paper,CuW1-xMoO4 powder samples were prepared by solid phase sintering method,and then,CuW1-xMoxO4 particle film photoanodes(x:?0.35)were prepared by subsequent drop-necking treatment.The light absorption characterization indicates that prepared CuW1-xMOxO4 particle film photoanodes were indeed narrow bandgap photoelectrodes with visible light response,and the band gap was gradually smaller as the Mo/W ratio increases.At the same time,the photoelectrochemical test showed that the photocurrent density of CuW1-xMoxO4 granule film photoanode was also gradually increased as the Mo/W ratio increases.The photocurrent density at 1.23 VRHE increased from 0.05 mA cm-2 to 0.1 mA cm-2under AM 1.5G simulated sunlight.However,because of the poor electrical connection between the particles in the granular film electrode,and even between the particles and the conductive substrate,so the conductivity of the electrode was very poor,which was harmful to the transmission of photogenerated carriers and affected the performance of photoelectrochemical water splitting.Research on Preparation and Photoelectrochemical Water Splitting Performance of CuW1-xMoxO4 Planar Film Photoanode.In order to deal with the problem of poor connectivity between particles in CuW1-xMoxO4 granular film photoanode prepared by solid phase sintering combined with drop-necking treatment,spray pyrolysis method with low cost and easy to be widely applied was used.UV-visible spectroscopy indicated that the band gap of CuW1-xMoxO4 decreased with the increase of Mo/W ratio and varied between 2.0-2.25 eV.The photocurrent test showed the photocurrent density of CuW1-xMoxO4 planar photoanode increased with the increase of Mo/W ratio.Under AM 1.5G simulated sunlight,the photocurrent density increased from 0.07mA cm-2 to 0.46 mA cm-2 at 1.23VRHE compared to CuWO4.After combining IPCE test and Mott-Schottky test,the reasons of the photocurrent density of CUW1-xMoxO4 planar film photoanodes increased with the increase of Mo/W ratio was researched.Finally,it was found that the increased utilization of incident photons as well as improved carrier concentration in the photoanodes and bulk charge separation efficiency are the two main reasons.