Synergistic effect of N-Ho on photocatalytic CO2 reduction for N/Ho co-doped TiO2 nanorods

The photoreduction of CO 2 by using Ho and N co-doped TiO 2 was explored. The doping elements can further improve the separation efficiency of photogenerated electron-hole pairs via refining grains, causing lattice distortion and adsorbing more hydroxyl radicals(·OH). We found that there exists product selectivity such that the photoreduction products of Ho/N-TiO 2 mainly consist of CO and methanol, while the counterparts of pristine TiO 2 are CO and methane. The possible mechanism of CO 2 reduction is depicted involving the generation and combination of specific radicals. Thus, the amount of ·OH adsorbed on the surface of the catalyst makes a significant difference in the selectivity in the reduction products. Ho/N-TiO 2 catalyst with the synergic effect of Ho and N showed the best photoreductive performance for CO 2 with H 2 O to CO and CH 4 , and its formation rate of CH 4 was 29 μmol/gcatal./hour.