Z-scheme S-modified Zn0.2Cd0.8S/α-Fe2O3 heterostructure for enhanced photoelectrochemical water oxidation

A Z-type heterojunction system is proven to be an efficient strategy to promote the separation of photo-generated carriers and maintain strong redox capacity for an enhanced photoanode. Herein, we synthesized a S-modified Fe2O3/Zn0.2Cd0.8S (Fe/ZCS) photoanode by one-pot hydrothermal treatment of FeOOH/Zn0.2Cd0.8S precursor film, followed by vapor deposition treatment. The as-synthesized S-modified Fe/ZCS displayed enhanced PEC water oxidation performance with a photocurrent density (2.76 mA cm−2) of about 2.63 times that of a pure phase Fe2O3 and 2.05 times that of Fe/ZCS at 1.23 VRHE. After 8 hours of continuous operation, the photocurrent density retention rate was still 96.4% demonstrating its satisfactory stability. Benefiting from the morphology of fine nanorods, the fabricated Z-scheme heterostructure exhibited strong oxidation-reduction ability and the well-distributed Fe(III)-SO4−2 bonds played key roles as the electron capture centers. The fabricated Z-scheme photoanode exhibited prospective applications in sustainable photoelectrochemical water oxidation.