Well-designed α-Fe2O3/ZnFe2O4 heterojunction for photocatalytic CO2 reduction to fuels

Abstract

Spinel ZnFe2O4 photocatalyst has been widely applied in CO2 reduction due to its negative enough conduction band edge and relatively narrow band gap, which enable the generation of strong reduction electrons in the presence of light irradiation. Unfortunately, the catalytic performance of pure ZnFe2O4 was seriously hindered because of inefficient charge transfer. Here, Z-scheme α-Fe2O3/ZnFe2O4 heterojunctions were synthesized by coupling α-Fe2O3 nanosheets with spinel ZnFe2O4 nanoparticles and applied to the photoreduction of CO2. The α-Fe2O3/ZnFe2O4 heterojunctions realized high charge separation efficiency and strong redox ability. As a result, the CH4 generation rate of α-Fe2O3/ZnFe2O4 heterojunctions was 2.6 times higher than that of ZnFe2O4. This work exhibits a new strategy to design ZnFe2O4-based Z-scheme heterojunction for converting CO2 to hydrocarbon fuels.