Photocatalytic CO2 reduction highly enhanced by oxygen vacancies on Pt-nanoparticle-dispersed gallium oxide

Abstract

Photocatalytic CO2 reduction on metal-oxide-based catalysts is promising for solving the energy and environmental crises faced by mankind. The oxygen vacancy (V o) on metal oxides is expected to be a key factor affecting the efficiency of photocatalytic CO2 reduction on metal-oxide-based catalysts. Yet, to date, the question of how an V o influences photocatalytic CO2 reduction is still unanswered. Herein, we report that, on V o-rich gallium oxide coated with Pt nanoparticles (V o-rich Pt/Ga2O3), CO2 is photocatalytically reduced to CO, with a highly enhanced CO evolution rate (21.0 μmol·h−1) compared to those on V o-poor Pt/Ga2O3 (3.9 μmol·h−1) and Pt/TiO2(P25) (6.7 μmol·h−1). We demonstrate that the V o leads to improved CO2 adsorption and separation of the photoinduced charges on Pt/Ga2O3, thus enhancing the photocatalytic activity of Pt/Ga2O3. Rational fabrication of an V o is thereby an attractive strategy for developing efficient catalysts for photocatalytic CO2 reduction.