Cs,Rh-codoped WO3 with a core–shell structure responsive up to 600 nm as an O2-evolving photocatalyst for Z-schematic water splitting

Abstract

Cs,Rh-codoped WO₃ showed photocatalytic activity for O₂ evolution from an aqueous Fe(ClO₄)₃ solution under irradiation of light with a wavelength longer than 500 nm, although the activities of nondoped, Rh-doped, and Cs-doped WO₃ were negligible. The optimized WO₃ codoped with Cs (5 mol%) and Rh (0.5 mol%) responded to visible light up to 600 nm. Moreover, the Cs,Rh-codoped WO₃ was successfully applied as an O₂-evolving photocatalyst for Z-schematic water splitting into H₂ and O₂ stoichiometrically with a H₂-evolving photocatalyst and an Fe^3+/2+ redox mediator under irradiation of light with a wavelength longer than 500 nm.