Efficient separation and transport of charge is a critical issue in solar-driven water oxidation. Herein, we developed a novel, facile, controllable method based on zero-valent iron (ZVI) reduction to in-situ and synchronous generate oxygen vacancies (O_v) and FeO_x oxygen evolution co-catalysts (OECs) on BiVO₄ for ultrafast electron transfer and excellent photoelectrochemical (PEC) water oxidation. In this method, a moderate and controllable ZVI reduction was the critical step to ensure whole penetration of O_v from BiVO₄ to FeO_x layer. This is because a special galvanic cell is formed between ZVI and BiVO₄, making it easy to capture oxygen atom from BiVO₄ and obtain a FeO_x layer (5 nm) outside simultaneously in oxygen-free annealing. The O_v can extend light absorption by narrowing bandgap and significantly improve electron mobility (8.6×10^-7 cm² s^-1) by reducing the trap-assisted recombination, which is 6.1-fold of BiVO_4. Meanwhile, electron lifetime increases from 11.6 to 115.3 ms. Ultrathin FeO_x layer provides more sites and dramatically reduces OER over-potential of 210 mV, resulting in fast hole-to-oxygen kinetics. A photocurrent of 3.13 mA·cm⁻² at 1.23 V_RHE is achieved for PEC water oxidation, which is 4.6-fold of pristine BiVO₄. This work provides a new path to overcome charge transport limitations and achieve enhanced solar water oxidation.

电荷的有效分离和传输是太阳能驱动水氧化过程中的关键问题。本文中，我们开发了一种基于零价铁（ZVI）还原的新颖，简便，可控制的方法，以在BiVO ₄上原位并同步产生氧空位（O _v）和FeO _x氧释放助催化剂（OEC），从而实现超快电子转移和出色的光电化学（PEC）水氧化。在这种方法中，适度和可控的ZVI还原是确保O _v从BiVO ₄完全渗透到FeO _x层的关键步骤。这是因为在ZVI和BiVO ₄之间形成了特殊的原电池，从而易于从BiVO捕获氧原子参照图₄，在无氧退火中同时在外部获得FeO _x层（5nm）。O _v可以通过缩小带隙来扩展光吸收，并通过减少陷阱辅助复合（BiVO _4的6.1倍）来显着提高电子迁移率（8.6×10 ^-7 cm ² s ^-1）。 11.6至115.3毫秒。超薄的FeO _x层提供了更多的位置，并大大降低了210 mV的OER过电位，从而实现了快速的空穴-氧动力学。PEC水氧化时，在1.23 V _RHE处获得3.13 mA·cm ^-2的光电流，是原始BiVO的4.6倍₄。这项工作提供了一条新的途径来克服电荷传输的局限性并实现增强的太阳能氧化作用。