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

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%.