新型S型CdS-BiVO4异质结光电极的构筑及产氢性能研究

通过化学浴和连续离子层沉积法构筑了BiVO₄/CdS和CdS/BiVO₄两种S型异质结薄膜光电极. 利用扫描电子显微镜(SEM)、 X射线衍射(XRD)、 紫外-可见吸收光谱(UV-Vis)以及电化学阻抗谱(EIS)对其形貌、 结构和光电性能进行了表征, 测试了两种薄膜电极的光催化和光电催化产氢性能. 结果表明, CdS和BiVO₄之间形成S型异质结, BiVO₄/CdS表现出最佳的光催化产氢性能, 而CdS/BiVO₄表现出最佳的光电催化产氢性能. 借助表面光电压技术探究了两种薄膜电极中S型异质结内建电场的形成过程和载流子传输的机制.

Construction of a Novel S-scheme CdS-BiVO4 Heterojunction Photoelectrodes and Research on Hydrogen Production

The single component photocatalysts have low photocatalytic hydrogen production efficiency due to the serious recombination of photogenerated electrons and holes and the mismatch of redox capacity and light absorption range. CdS/BiVO₄ and BiVO₄/CdS S-scheme heterojunction film photoelectrodes were prepared via chemical bath deposition and successive ionic layer adsorption and reaction method， respectively. The morphology， structure， optical and photoelectrochemical properties of the two film electrodes were characte-rized by scanning electron microscopy（SEM）， X-ray diffraction（XRD）， ultraviolet-visible（UV-Vis） spectro-scopy， and electrochemical impedance spectroscopy（EIS）， and the photocatalytic and photoelectrocatalytic hydrogen production properties of the two film electrodes were tested. The results show that S-scheme heterojunction formed between CdS and BiVO₄， BiVO₄/CdS shows the best photocatalytic hydrogen production performance， while CdS/BiVO₄ shows the best photoelectrocatalytic hydrogen production performance. With the help of surface photovoltage technology， the formation process of the built-in electric field and the carrier transport mechanism of S-scheme heterojunction in the two film electrodes are explored.