Effective Driving of Ag-Loaded and Al-Doped SrTiO 3 under Irradiation at λ > 300 nm for the Photocatalytic Conversion of CO 2 by H 2 O

Al-doped strontium titanite (Al–SrTiO 3 ) containing numerous stepwise edges on the surface was found to exhibit an excellent performance in the photocatalytic conversion of CO 2 by H 2 O as an electron donor under photoirradiation at >300 nm with Ag modification, while in contrast, the Ag-loaded pristine SrTiO 3 was inactive as a photocatalyst for this reaction. CO was stably evolved as the main reduction product at a rate of 7.2 μmol h –1 over the Ag-loaded Al–SrTiO 3, and a small amount of H 2 was generated during the three runs. The selectivity of electrons generated by charge transfer toward CO evolution was ∼98.0%. In addition, the stoichiometric formation of O 2 was observed, indicating that H 2 O acts as an electron donor for the reduction of CO 2 . Furthermore, isotopic experiments performed using 13 CO 2 revealed that the CO product is derived from CO 2 bubbled into an aqueous solution of NaHCO 3 and not from residual carbon species on the catalyst surface.