Highly efficient sustainable photocatalytic Z-scheme hydrogen production from an α-Fe2O3 engineered ZnCdS heterostructure

Abstract

We present an α-Fe2O3/Zn0.4Cd0.6S heterostructure that shows visible light photocatalytic H2 production as high as 536.8μmolh−1 with apparent quantum efficiency of 11.2% at 420nm. The UV–vis diffuse reflectance spectra of as-synthesized α-Fe2O3/Zn0.4Cd0.6S heterostructure reveal efficient absorption in the visible region, which is a key factor in the enhanced catalytic activity. Moreover, the increase in charge separation efficiency of α-Fe2O3/Zn0.4Cd0.6S suggested by electrochemical impedance spectroscopy and photocurrent response also results in enhanced photocatalytic H2 production. The interface contact between α-Fe2O3 and Zn0.4Cd0.6S ascertained from HRTEM images promotes the recombination of photogenerated electrons from the conduction band of α-Fe2O3 and holes from the valence band of Zn0.4Cd0.6S, thus enhancing the utilization of solar light and increasing the efficiency. Our coupling approach to synthesizing an efficient Z-scheme photocatalyst provides insight into the design of further solar energy utilization photocatalysts.