Enhanced Photoelectrochemical Performance of BiVO Photoanodes Co-Modified with Borate and NiFeO.

Despite significant progress in photoelectrochemical (PEC) water splitting, high fabrication costs and limited efficiency of photoanodes hinder practical applications. Bismuth vanadate (BiVO), with its low cost, non-toxicity, and suitable band structure, is a promising photoanode material but suffers from poor charge transport, sluggish surface kinetics, and photocorrosion. In this study, porous monoclinic BiVO films are fabricated via a simplified successive ionic layer adsorption and reaction (SILAR) method, followed by borate treatment and PEC deposition of NiFeO. The resulting B/BiVO/NiFeO photoanode exhibits a significantly enhanced photocurrent density of 2.45 mA cm at 1.23 V vs. RHE-5.3 times higher than pristine BiVO. It also achieves an ABPE of 0.77% and a charge transfer efficiency of 79.5%. These results demonstrate that dual surface modification via borate and NiFeO is a cost-effective strategy to improve BiVO-based PEC water splitting performance. This work provides a promising pathway for the scalable development of efficient and economically viable photoanodes for solar hydrogen production.