Photo-thermal coupling-mediated enhancement in CO2 conversion: Key role of thermal effect and cobalt valence change-regulated electron-transfer orientation

Solar-driven CO 2 conversion into fuels using particulate photocatalysts is a promising strategy for mitigating CO 2 emissions with minimal environmental impact. However, the efficiency of CO 2 photoreduction remains limited by the inherent trade-off between light absorption and charge transfer kinetics in single photocatalysts. Herein, we propose an innovative microtubular photocatalytic system consisting of integrated photothermal-photocatalytic materials. The system is based on hollow microtubular g-C 3 N 4 substrates, which are wrapped with thin layers of graphene oxide (GO) acting as photothermal generators, while CoS 2 nanoparticles are embedded between the layers to facilitate charge transfer. The synergistic effects of photon and thermal energy significantly reduce the activation energy by approximately 14 times, thereby promoting oriented electron transfer. Under full spectrum irradiation, the system exhibits superior CO 2 reduction performance, achieving CO and CH 4 yields of 143.73 and 60.27 μmol g −1 , respectively, surpassing the combined contributions from light and heat alone.