Elevated photoelectrochemical activity of FeVO4/ZnFe2O4/ZnO branch-structures via slag assisted-synthesis

Abstract

Efficient recycling of industrial slag and renewable energy harvesting have become two global subjects. In this work, by recycling rare-earth oxide (REO) slag as the iron source, FeVO₄/ZnFe₂O₄/REO (FVO/ZFO/REO) core–shell–shell nanorods (NRs) are fabricated on ZnO NRs and exhibit obviously enhanced photoelectrochemical (PEC) efficiency. The results confirm that the enhanced light absorption and conversion are attributed to the narrow band gap of ZFO. The improved electron–hole separation and charge migration can be facilitated by the cascade band alignment of ZFO, FVO and ZnO, and the branched nanotaper structures; the lifetime of the electron can be prolonged by the REO passivation layers, leading to efficient PEC enhancement. This study broadens the application of REO slag as a building block for PEC anodes and demonstrates a novel hetero-PEC anode. Overall, recycling of industrial slag could make a crucial contribution to the clean and renewable energy.