Constructing semiconductor heterojunctions via surface/interface engineering is an effective way to enhance the charge carrier separation/transport ability and thus the photoelectrochemical (PEC) properties of a photoelectrode. Herein, we report a conformal BiVO₄-layer/WO₃-nanoplate-array heterojunction photoanode modified with cobalt phosphate (Co-Pi) as oxygen evolution cocatalyst (OEC) for significant enhancement in PEC performances. The BiVO₄/WO₃ nanocomposite is fabricated by coating a thin conformal BiVO₄ layer on the surface of presynthesized WO₃ nanoplate arrays (NPAs) via stepwise spin-coating, and the decoration of Co-Pi OEC is realized by photoassisted electrodeposition method. The optimized [email protected]₄/WO₃ heterojunction photoanode shows a maximum photocurrent of 1.8 mA/cm² at 1.23 V vs RHE in a phosphate buffer electrolyte under an AM1.5G solar simulator, which is 5 and 12 times higher than those of bare WO₃ and BiVO₄ photoanode, respectively. Measurements of UV–vis absorption spectra, electrochemical impedance spectra (EIS) and photoluminescence (PL) spectra reveal that the enhanced PEC performances can be attributed to the increased charge carrier separation/transport benefited from the type II nature of BiVO₄/WO₃ heterojunction and the promoted water oxidation kinetics and photostability owing to the decoration of Co-Pi cocatalyst.

中文翻译：

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磷酸钴钴修饰的共形BiVO ₄层/ WO ₃纳米板阵列异质结光阳极，可显着提高光电化学性能

通过表面/界面工程构造半导体异质结是增强电荷载流子分离/传输能力并因此提高光电极的光电化学（PEC）特性的有效方法。在这里，我们报告了共形的BiVO ₄层/ WO ₃纳米板阵列异质结光阳极，用磷酸钴（Co-Pi）修饰为析氧助催化剂（OEC），可显着增强PEC性能。BiVO ₄ / WO ₃纳米复合材料是通过在预先合成的WO ₃表面上涂覆一层薄的保形BiVO ₄层而制成的。通过逐步旋涂法制备纳米板阵列（NPA），并通过光辅助电沉积方法实现Co-Pi OEC的装饰。经过优化的[受电子邮件保护] ₄ / WO ₃异质结光电阳极在AM1.5G太阳模拟器下在磷酸盐缓冲电解液中的相对于RHE的条件下，在1.23 V时的最大光电流为1.8 mA / cm ²，比RHE高5倍和12倍。裸WO ₃和BiVO ₄光电阳极。紫外可见吸收光谱，电化学阻抗光谱（EIS）和光致发光（PL）光谱的测量表明，增强的PEC性能可归因于BiVO _4的II型性质，电荷载流子的分离/传输增加/ WO ₃异质结和由于修饰Co-Pi助催化剂而提高的水氧化动力学和光稳定性。