Photoelectrochemical (PEC) devices have become one of the most attractive clean energies due to its potential high efficiency and simplicity but it is very challenging to make a highly efficient and stable practical device. Up to date, BiVO₄ as the most promising ternary metal-oxide photoanode can only achieve a photocurrent of no more than 1.0mAcm^-2, which is far below its theoretical value (7.5mAcm^-2), and is mainly caused by its high charge recombination from defects and sluggish water oxidation kinetics. Herein we fabricate a BiVO₄/ferroelectric BiFeO₃ composite photoanode by a surface passivation approach to greatly enhance photocurrent by ~4.4 times plus ~400 mV negative shift of the onset potential than the plain BiVO₄. BiVO₄/BiFeO₃ also greatly decreases charge recombination rate from 17s^-1 to 0.6s^-1 in comparison to the plain BiVO₄ by ~28 times. The PEC performance of BiVO₄/BiFeO₃ can also be manipulated based on the direction of self-polarization in BiFeO₃. Moreover, BiVO₄/BiFeO₃ shows much better stability than that of the BiVO₄ as well as BiVO₄/Co-Pi. It is discovered that the PEC performance enhancement mechanism is attributed to the BiFeO₃ passivation for a bifunctional film as a buffer layer to significantly reduce charge recombination while as an efficient catalyst to boost charge separation/transfer.

中文翻译：

---

双功能铁电BiFeO3钝化BiVO4光电阳极，可高效稳定地氧化太阳能。

光电化学（PEC）器件由于其潜在的高效率和简单性而已成为最有吸引力的清洁能源之一，但制造高效，稳定的实用器件非常具有挑战性。迄今为止，BiVO ₄作为最有前途的三元金属氧化物光电阳极只能实现不超过1.0mAcm ^-2的光电流，这远低于其理论值（7.5mAcm ^-2），这主要是由于其高电导率所致。缺陷和缓慢的水氧化动力学引起的电荷重组。在此，我们制造BiVO ₄ /铁电BiFeO ₃复合光阳极采用表面钝化方法，与普通BiVO ₄相比，可将光电流大大提高约4.4倍，加上起始电势的负400 mV负移。与普通的BiVO ₄相比，BiVO ₄ / BiFeO ₃还将电荷复合率从17s ^-1降低到0.6s ^-1约28倍。BiVO ₄ / BiFeO ₃的PEC性能也可以基于BiFeO _3中的自极化方向进行控制。此外，BiVO ₄ / BiFeO _3的稳定性比BiVO ₄和BiVO ₄更好。/副总裁。已经发现，PEC性能增强机制归因于BiFeO ₃钝化，用于双功能膜作为缓冲层，可显着减少电荷重组，同时又是促进电荷分离/转移的有效催化剂。