Cu/Ni-loaded oxygen vacancy-rich CeO₂ rod derived from metal organic framework for efficient photothermal CO₂ hydrogenation

Photothermal catalytic CO₂ reduction can combine photocatalysis and thermal catalysis by using full-spectrum solar energy to convert CO₂ into high value-added chemicals. This can effectively alleviate the problems of excessive CO₂ emissions and thermal catalytic energy waste. In this paper, a novel catalyst was prepared using Ce-MOF as a precursor to generate Cu/Ni/CeO₂ for efficient reduction of CO₂ to CO by hydrogenation. Due to the rod-like structure of CeO₂ and the high dispersion of Cu and Ni nanoparticles, 10%Cu 5%Ni CeO₂ can achieve a catalytic activity of 54.21 mmol g⁻¹ h⁻¹ in the full solar spectrum. The supported Cu and Ni metals are the active sites for catalytic reduction. Meanwhile, Cu and Ni enhanced the light absorption ability of the catalyst and the surface temperature under illumination. This is due to the hot charge carriers generated by LSPR effect in Ni and Cu metal nanoparticles, which can dissipate energy through local heating, thus increasing the temperature of the catalyst under illumination. It can be found that the CO₂ reduction activity of photo-assisted thermocatalysis is higher than that of thermal catalysis under the same conditions. Therefore, the combined effect of the electrons generated by UV–Vis light and the heating effect of near-infrared light on catalyst could improve the catalytic activity. This work might provide a potential strategy for efficient photothermal reduction of CO₂ in the future.