Tao Chen, Jiang Yi, Ding Yunxuan, Jia Bingquan, Liu Ruitong, Li Peifeng, Yang Wenxing, Xia Lixin, Sun Licheng, Zhang Biaobiao
College of Chemistry, Liaoning University, Shenyang 110036, Liaoning, China.
Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou 310024, Zhejiang, China.
JACS Au. 2023 Jul 13;3(7):1851-1863. doi: 10.1021/jacsau.3c00100. eCollection 2023 Jul 24.
Monoclinic BiVO is one of the most promising photoanode materials for solar water splitting. The photoelectrochemical performance of a BiVO photoanode could be significantly influenced by the noncovalent interactions of redox-inert metal cations at the photoanode-electrolyte interfaces, but this point has not been well investigated. In this work, we studied the Cs-dependent surface reconstruction and passivation of BiVO photoanodes. Owing to the "structure breaker" nature of Cs, the Cs at the BiVO photoanode-electrolyte interfaces participated in BiVO surface photocorrosion to form a Cs-doped bismuth vanadium oxide amorphous thin layer, which inhibited the continuous photocorrosion of BiVO and promoted surface charge transfer and water oxidation. The resulting cocatalyst-free BiVO photoanodes achieved 3.3 mA cm photocurrent for water oxidation. With the modification of FeOOH catalysts, the photocurrent at 1.23 V reached 5.1 mA cm, and a steady photocurrent of 3.0 mA cm at 0.8 V was maintained for 30 h. This work provides new insights into the understanding of Cs chemistry and the effects of redox-inert cations at the electrode-electrolyte interfaces.
单斜晶系的BiVO是用于太阳能水分解的最有前途的光阳极材料之一。BiVO光阳极的光电化学性能可能会受到光阳极 - 电解质界面处氧化还原惰性金属阳离子的非共价相互作用的显著影响，但这一点尚未得到充分研究。在这项工作中，我们研究了BiVO光阳极的Cs依赖性表面重构和钝化。由于Cs的“结构破坏者”性质，BiVO光阳极 - 电解质界面处的Cs参与了BiVO表面光腐蚀，形成了Cs掺杂的铋钒氧化物非晶薄层，这抑制了BiVO的持续光腐蚀，并促进了表面电荷转移和水氧化。所得的无共催化剂BiVO光阳极实现了3.3 mA cm的水氧化光电流。通过FeOOH催化剂的修饰，1.23 V时的光电流达到5.1 mA cm，并且在0.8 V时3.0 mA cm的稳定光电流保持了30小时。这项工作为理解Cs化学以及电极 - 电解质界面处氧化还原惰性阳离子的影响提供了新的见解。
