Bismuth vanadate (BiVO₄) as a promising photoelectrode has been received an increasing attention for photoelectrochemical (PEC) water splitting. However, the severe surface charge recombination of BiVO₄ still limited the PEC water splitting efficiency. Herein, a simple process is developed for preparing ternary spinel MCo₂O₄ (M = Mn, Zn) nanoparticles on the surface of BiVO₄ photoelectrode as an efficient co-catalyst and constructed p-n junction to suppress the surface charge recombination. The as-prepared best MnCo₂O₄/BiVO₄ and ZnCo₂O₄/BiVO₄ photoelectrodes have exhibited a remarkable photocurrent density of 2.8 mA/cm² and 2.2 mA/cm² at 1.23 V versus the reversible hydrogen electrode (RHE) under AM 1.5 G illumination, which is about 3.5 and 2.7 times than the bare BiVO₄ photoelectrode, respectively. The deposition of MCo₂O₄ (M = Mn, Zn) co-catalyst has yielded a large cathodic shift in the onset potential of BiVO₄. The PEC studies suggest that the MCo₂O₄ (M = Mn, Zn) co-catalyst could boost the photogenerated holes transference and enhance the charge separation efficiency in the semiconductor-electrolyte interface. The prominent PEC activity shows that the MCo₂O₄/BiVO₄ photoelectrodes could be used in solar water splitting.

钒酸铋（BiVO ₄）作为一种有前途的光电极，在光电化学（PEC）水分解中受到越来越多的关注。但是，BiVO ₄的剧烈表面电荷复合仍然限制了PEC的水分解效率。在本文中，开发了一种简单的方法以在BiVO ₄光电极表面上制备三元尖晶石MCo ₂ O ₄（M = Mn，Zn）纳米粒子作为有效的助催化剂，并构建了pn结以抑制表面电荷复合。最佳制备的MnCo ₂ O ₄ / BiVO ₄和ZnCo ₂ O ₄ / BiVO ₄与在AM 1.5 G光照下的可逆氢电极（RHE）相比，光电极在1.23 V下表现出了显着的光电流密度，分别为2.8 mA / cm ²和2.2 mA / cm ²，是裸BiVO ₄光电电极的3.5倍和2.7倍，分别。MCo ₂ O ₄（M = Mn，Zn）助催化剂的沉积在BiVO ₄的起始电势上产生了很大的阴极位移。PEC研究表明，MCo ₂ O ₄（M = Mn，Zn）助催化剂可以促进光生空穴的转移，并提高半导体-电解质界面中的电荷分离效率。杰出的PEC活动表明，MCo₂ O ₄ / BiVO ₄光电电极可用于太阳能水分解。