Artificial photosynthesis for solar hydrogen generation over transition-metal substituted Keggin-type titanium tungstate

摘要

The photocatalytic hydrogen (H2) evolution with transition-metal substituted Keggin-type titanium tungstates Na_(5(6))[MTiW_(11)O_(39)]·xHaO (abbreviated as TiW_(11)M (M - Fe, Co, Zn)) as photocatalyst was reported. They showed good photocatalytic activities toward H2 evolution in homogeneous systems under simulated solar light irradiation. The order of photocatalytic activity was TiW_(11)Co ≈ TiW_(11)Zn > TiW_(11)Fe ? H3PW_(12)O_(40) (PW_(12)). The selected POMs showed good stability during the reactions. Karl Fischer analysis, ICPE (Inductive Coupled Plasma Emission) and FT-IR (Fourier Transform Infrared Spectroscopy) were used to confirm the composition and structure. UV-Vis absorption spectra, kinetics investigation and cyclic voltammetric characterizations were used to explain the photocatalytic results. Finally, an analogous "Z-scheme" mechanism was proposed for the homogeneous systems toward photocatalytic H2 evolution under simulated solar light irradiation.