In-situ surface reconstruction of BiVO4/CuFe2O4 photoanode for efficient and robust solar water oxidation
Tengfei Wang, Kai Song, Houjiang Liu, Hongyan Li, Yufei Zhang, Weijie Ren, Rui Zhang, Kun Li, Fang He, Zhenxing Qin, Huilin Hou
Abstract
Photoelectrochemical (PEC) water splitting is a promising approach for sustainable hydrogen production, yet it faces challenges in achieving efficient charge separation and stable photoanode operation. In this work, we develop a BiVO 4 /CuFe 2 O 4 (BVO/CFO) heterojunction photoanode with in-situ surface reconstruction capabilities to enhance PEC performance and operational durability. The BVO/CFO heterojunction , formed by coupling n-type BVO with p-type CFO, effectively reduces charge recombination through an intrinsic electric field, promoting efficient charge separation. The BVO/CFO photoanode exhibits a photocurrent density of 2.77 mA cm −2 and a charge separation efficiency of 79.7 % at 1.23 V vs. RHE. After loading NiOOH co-catalysts, the photocurrent density increases to 3.72 mA cm −2 . More importantly, under PEC conditions, the surface of CFO undergoes in-situ reconstruction, forming an FeOOH layer that serves as a robust oxygen evolution reaction (OER) catalyst, enhancing water oxidation kinetics and providing protection against photocorrosion. The BVO/CFO/FeOOH photoanode, formed via this in-situ surface reconstruction process, achieves a photocurrent density of 4.07 mA cm −2 and a charge injection efficiency of 75.4 %. Our study highlights the effectiveness of integrating heterojunction engineering with adaptive surface reconstruction, offering a scalable pathway to high-performance, durable PEC systems for solar-driven hydrogen production.