Synergistic effects of Zn and Pd species in TiO2 towards efficient photo-reduction of CO2 into CH4

A Zn and Pd co-modified TiO2 photocatalyst exhibits remarkably enhanced photocatalytic activity upon reduction of CO2 into CH4. Owing to the synergistic effect of unique O-Zn-Cl and O-Pd-O species, TiO2-PdX-ZnY presents enhanced visible absorption and efficient charge carrier separation. It can be deduced from theoretical calculations and experimental results that the energy levels of O-Zn-Cl and O-Pd-O satisfy the redox potential of CO2 reduction, improving the photocatalytic performance. These results suggest that introducing multi-surface species to produce synergetic effects is a feasible route for efficient photocatalysis.