Constructing SrCO3/SrTiO3 nanocomposites with highly selective photocatalytic CO2-to-CO reduction

Abstract

In this study, a SrCO3/SrTiO3 (SCO/STO) catalyst for highly selective photocatalytic CO2-to-CO reduction is prepared via in-situ synthesizing SrCO3 on the surface of SrTiO3 nanosheets by the hydrothermal method. The SCO/STO photocatalyst consists of cubic phase STO and orthorhombic phase SrCO3 nanosheets. The catalyst surface also exhibits more expose active sites and oxygen vacancies than the pure STO. The photocatalyst CO2 reduction test shows the highly active in converting CO2 into CO, with a production rate of ~23.82 µmol g−1 h−1. The calculations of the adsorption energy of CO indicate why the SrCO3/SrTiO3 has distinguished performance and selectivity for CO at the photocatalytic reduction of CO2. In addition, surface oxygen vacancies and the SCO/STO heterojunction structure would enhance the charge separation, further improving its photocatalytic activities. This work provides a simple method via the in-situ construction of heterojunction composites for photocatalytic CO2 reduction.