Characterization and DFT Research of Nd/TiO2: Photocatalyst for Synthesis of Methanol from CO2and H2O

Nd3+–doped TiO2 synthesized via the sol-gel method, was used as catalyst for photoreduction of carbon dioxide into methanol in an aqueous solution under UV irradiation. The catalysts were characterized by XRD, IR, UV-vis etc. The maximum photocatalytic activity corresponds to the 0.2 wt.% Nd3+–doped TiO2nanopowders. In that case, the methanol yield is 184.8μmol/g by 8h UV irradiation, indicating that the Nd/TiO2can obviously enhance the efficiency of photocatalytic reduction comparing to pure TiO2. Furthermore, the adsorption properties of Nd atom on the regular (110) surface of rutile and (101) surface of anatase were studied by density functional calculations under the B3LYP level. H2O molecule catches the photo-induced hole in the reaction system forming H2O+ which dissociates further into H+and OH radical on the catalyst surface. The transition state was found by DFT calculation, and the amount of the OH radicals has effects on the selectivity of CH3OH.