The Function of Photocatalytic Performance and Carrier Separation Efficiency Tuned by Doping Content in Homogeneous Photocatalysts

Homogeneous matrix materials are considered to be a solid guarantee of site-point charge transfer reactions because they are the main body of light absorption, photogenerated carrier separation, migration, and recombination processes. Elucidating the effect of carrier separation efficiency on catalytic performance is of great significance for overcoming the optimization obstacles of homogeneous matrix parts and providing new design strategies. In this study, TiO2 doped with Fe as the research object quantifies the carrier dynamics while trying to avoid large site and lattice changes. The direct correlation between carrier separation efficiency and photocatalytic performance with different doping content samples is clearly elucidated by carrier dynamic characterization results. Doping of 0.213 wt.% Fe exhibits the best catalytic performance, achieving CO yield of 35.12 µmol g-1 h-1. Especially, the femtosecond transient absorption spectroscopy demonstrates the defect level formed by doping Fe enhances the separation of photogenerated electrons. The clear relationship shown above, which is catalytic capacity mapping with carrier separation efficiency, rather than a linear dependence on sites and oxygen vacancies, fully demonstrates the great potential of simple doping strategies for homogeneous photocatalysts.