Brookite TiO2 Nanoparticles Decorated with Ag/MnOx Dual Cocatalysts for Remarkably Boosted Photocatalytic Performance of the CO2 Reduction Reaction

The solar-driven CO2 reduction reaction (CO2RR) for producing chemical fuels is considered to be a promising approach to dealing with the growing energy crisis and greenhouse effect. Herein, novel Ag/MnOx dual-cocatalyst-decorated brookite titania (BT) nanoparticles with remarkably boosted photocatalytic CO2RR performance are prepared through a facile photodeposition method. The resultant xAg-BT-yMn composite with optimal cocatalyst content delivers amazing CO/CH4 yields of 31.70/129.98 μmol g-1 with an overall photoactivity of 1103.28 μmol g-1 h-1, 11.98 times higher than that of the BT nanoparticles alone. Further investigations demonstrate that the dual cocatalysts decorating the BT nanoparticles not only effectively retard the photoinduced charge recombination but also significantly vary the surface chemical feature to promote the adsorption/activation of the reactants (CO2/H2O). In addition, the Ag nanoparticles can broaden the spectral response region, while the MnOx cocatalyst can promote the CH4 product selectivity and the water oxidation reaction. The synergistic effect of Ag/MnOx dual cocatalysts on the BT nanoparticles renders a remarkably boosted CO2RR performance, which provides a simple yet general synthesis strategy for brookite titania-based photocatalysts with high-performance solar-driven CO2 conversion.