Gas sensitization and photochromism of CaTiO3-δ for visible-light photocatalysis

Abstract

A wide bandgap CaTiO3-δ (CTO) with oxygen vacancy (VO) was prepared to investigate the sensitization or photochromism caused by the adsorbed gaseous species, and the resultant photocatalytic performance of CTO under visible light. The adsorption of CO2 was able to produce an intermediate gap state in CTO according to the density-function-theory (DFT) calculations and was found to increase the light absorption peak at 482 nm (A482). During photocatalytic NO oxidation in air, the VO on the surface could enhance adsorption and further oxidation of NO2 intermediates. Furthermore, the gas sensitization and photochromism of CTO contributed to the activation of O2 in dry air. Our findings will help deepen the knowledge about the chemisorption of gaseous species in the electronic structural tunability of semiconductors and the resultant impact on the photocatalytic reaction at the gas/solid interface.