Characterization and photocatalytic reduction of CO2 with H2O on Ti/FSM-16 synthesized by various preparation methods.
Ti/FSM-16 photocatalysts were prepared by various methods and their reactivity for the photocatalytic reduction of CO2 with H2O at 323 K was investigated. UV irradiation of Ti/FSM-16 in the presence of CO2 and H2O led to the formation of CH4 and CH3OH. The photocatalytic reactivity and selectivity differed remarkably by variations in the preparation method. Analyses of the UV-Vis absorption and XAFS spectra showed that the dispersion and local structure of the Ti-oxide species greatly depended on the preparation method. The formation of CH3OH was found to be related to the local structure of the Ti-oxide species while the yield of the photoluminescence was attributed to the charge transfer excited state of the highly dispersed tetrahedrally coordinated Ti-oxide species. Methanol formation was found to be more efficient on Ti/FSM-16 having such highly dispersed tetrahedrally coordinated Ti-oxide species.