Bismuth vanadate (BiVO₄) has attracted wide attention as photoanode in water-splitting photoelectrochemical (PEC) devices. However, its catalytic performance is greatly limited by the serious charge recombination on the surface states. Herein, borate modified BiVO₄ plus additional CoPi cocatalyst (B-BVO/CoPi) is developed as photoanode for PEC cell via a simple soaking and electrodeposition process. Based on the electrochemistry tests and material characteristics, the borate groups [B(OH)₄] ^– is able to effectively prevent the charge recombination, while the outer CoPi cocatalyst enhance the activity toward oxygen evolution reaction. Therefore, the designed B-BVO/CoPi photoanode could obtain a high current density of 2.67 mA cm⁻² at 1.23 V_RHE with an onset potential of 0.29 V_RHE, much higher than pristine BiVO₄ (0.78 mA cm⁻², 0.52 V_RHE). This work may provide a new insight for constructing multifunctional modified photoanodes for efficient solar conversion.

钒酸铋（BiVO ₄ ）作为水分解光电化学（PEC）器件中的光阳极引起了广泛关注。然而，其催化性能因表面态严重的电荷复合而受到极大限制。在此，通过简单的浸泡和电沉积过程，硼酸盐改性的 BiVO ₄加上额外的 CoPi 助催化剂 (B-BVO/CoPi) 被开发为PEC 电池的光阳极。根据电化学测试和材料特性，硼酸盐基团[B(OH) ₄ ] ^-能够有效防止电荷复合，而外部CoPi助催化剂则增强析氧反应的活性。因此，设计的B-BVO/CoPi光阳极可以在1.23 V _{RHE下获得2.67 mA cm} ^-2的高电流密度，起始电位为0.29 V _RHE，远高于原始BiVO ₄ (0.78 mA cm ^-2 , 0.52 V)_右旋）。这项工作可能为构建多功能改性光电阳极以实现高效太阳能转换提供新的见解。