Pyrochlore-structural Nd2Ta2O5N2 photocatalyst with an absorption edge of over 600 nm for Z-scheme overall water splitting

Abstract

A pyrochlore-structural oxynitride Nd₂Ta₂O₅N₂ with a visible light absorption edge of ca. 620 nm was explored for photocatalytic water splitting. Dual functions of Nd₂Ta₂O₅N₂ were confirmed by proton reduction and water oxidation half-reactions through separately loading Pt or CoO_x as a cocatalyst in the presence of the corresponding sacrificial reagent. Finally, the platinum modified sample (Pt/Nd₂Ta₂O₅N₂) was prepared and employed as the H₂-evolving photocatalyst to fabricate an effective photocatalytic Z-scheme overall water splitting together with PtO_x/WO₃ as the O₂-evolving photocatalyst and IO₃⁻/I⁻ as shuttle ions under visible light irradiation.