Effectively CO2 photoreduction to CH4 by the synergistic effects of Ca and Ti on Ca-loaded TiSiMCM-41 mesoporous photocatalytic systems

Abstract

TixSiMCM-41 is a mesoporous photocatalyst with a tetragonal framework and high structural regularity. In this study, Ca was introduced to the TixSiMCM-41 surfaces to improve CO2 absorption. The catalytic performance of mesoporous Ca/TixSiMCM-41 was superior to that of the reported Ca/TixSiO2 nano-sized composite catalyst. The photoreduction of CO2 to CH4 improved remarkably over the Ca(10.0wt.%)/Ti35Si65MCM-41 catalyst, producing 82.0μmolg−1catL−1 after an 8h reaction. A model for the enhanced photoactivity over Ca/TixSiMCM-41 was suggested, and the results were attributed to the effective charge separation and inhibited recombination of the photogenerated electron–hole pairs over Ca/TixSiMCM-41.