Silver-Inserted Heterojunction Photocatalysts for Z‑Scheme Overall Pure-Water Splitting under Visible-Light Irradiation

Overall pure-water splitting under visible-light irradiation was accomplished utilizing a solid-state heterojunction photocatalyst following the Z-scheme mechanism. Zinc rhodium oxide (ZnRh2O4) and defective silver antimonate (Ag1–x SbO3–y ) as hydrogen (H2)- and oxygen (O2)-evolution photocatalysts, respectively, were connected with silver (Ag) to prepare a solid-state Z-scheme photocatalysis system (ZnRh2O4/Ag/Ag1–x SbO3–y ). In this system, Ag acted as a solid-state electron mediator for the transfer of electrons from the conduction band of Ag1–x SbO3–y to the valence band of ZnRh2O4. Utilizing the thus-constructed ZnRh2O4/Ag/Ag1–x SbO3–y photocatalyst, the simultaneous liberation of H2 and O2 from pure water at a molar ratio of ∼2:1 was achieved under irradiation with visible light at over 500 nm.