Enhanced photocatalytic CO2 hydrogenation with wide-spectrum utilization over black TiO2 supported catalyst

Abstract Light-driven conversion of CO2 into chemicals/fuels is a desirable approach for achieving carbon neutrality using clean and sustainable energy. However, its scale-up application is restricted due to insufficient efficiency. Herein, we present a photothermal catalytic hydrogenation of CO2 into CH4 over Ru/black TiO2 catalysts, aiming to achieve the synergistic use of light and heat in solar energy during CO2 conversion. Owing to the desirable spectral response ability and photothermal conversion performance of black TiO2, an efficient combination of photocatalysis and thermocatalysis has been established. The CO2 hydrogenation was significantly accelerated because of the increased catalyst surface temperature enabled by the photothermal effect of black TiO2. Simultaneously, through the in situ X-ray photoelectron spectroscopy (XPS) observation, electron-rich Ru nanoparticles was achieved based on the photo-induced excitation, thereby providing more negative hydride to improve nucleophilic attack to the CO2, obtaining the CH4 yield of 93.8%.