Interface reacted ZnFe2O4 on α-Fe2O3 nanoarrays for largely improved photoelectrochemical activity

Abstract

ZnFe₂O₄/α-Fe₂O₃ heterojunctions were successfully synthesized by depositing ZnO films on α-Fe₂O₃ nanorods through the atomic layer deposition technique, followed by annealing in air. The as-fabricated heterostructures showed a significant enhancement in photoelectrochemical (PEC) performance when compared to the bare α-Fe₂O₃, with photocurrent density increasing from 0.03 mA cm⁻² for pristine α-Fe₂O₃ to 0.29 mA cm⁻². The increased photocurrent for the ZnFe₂O₄/α-Fe₂O₃ heterojunction was ascribed to the enhanced charge carrier density and the efficient separation of electron–hole pairs at the ZnFe₂O₄/α-Fe₂O₃ interface. The significant performance enhancement suggests that the rational design and construction of the heterostructures with suitable band alignment as photoelectrodes are promising to achieve highly efficient PEC water splitting.