Fabricating BiVO4/FeOOH/ZnFe-LDH hierarchical core–shell nanorod arrays for visible-light-driven photoelectrochemical water oxidation

Abstract

In this paper, porous BiVO₄ nanorod arrays were encapsulated with FeOOH and ZnFe layered double hydroxide (ZnFe LDH) for the construction of hierarchical structures to achieve excellent transfer and separation of photogenerated electron–hole pairs. With the decoration of FeOOH and ZnFe LDH, the as-prepared BVO/FeOOH/ZnFe LDH ternary photoanode exhibits enhanced visible light absorption, increased carrier density, lower charge transfer resistance, boosted charge injection, bulk separation efficiency, and enhanced PEC performance, as compared with that of bare BiVO₄. The experimental results suggest improved electron transport and matched energy bands, along with the accelerated hole capture and improved water oxidation kinetics from cocatalysts. In addition, with the decoration of FeOOH and ZnFe LDH, the as-prepared BVO/FeOOH/ZnFe LDH ternary photoanode exhibited outstanding structural stability during the application process. This work could give a perspective for investigating photoelectrochemical water splitting in a BiVO₄ heterostructural photoanode for an enhanced visible light response and boosted PEC performance.