Solar Photothermal CO2 Conversion: Harnessing Light and Heat for Carbon Neutrality: A Mini Review

Photothermal CO2 conversion is a promising strategy for sustainable solar fuel production, which integrates photocatalytic and thermocatalytic processes to enhance solar energy utilization, reaction kinetics, and product selectivity. By coupling photon-induced charge excitation with localized thermal effects, photothermal systems enable the efficient activation of thermodynamically stable CO2 molecules under relatively mild conditions. This review provides a comprehensive overview of the fundamental principles underlying photocatalysis and thermocatalysis, and their synergistic effects in photothermal catalysis. It discusses photonic–thermal coupling, plasmonic and non-plasmonic pathways, and major CO2 conversion routes such as hydrogenation and artificial photosynthesis. Advances in the design of efficient nanostructured catalysts, focusing on light absorption, heat management, charge dynamics, and optofluidic reactors, are also highlighted. Despite significant progress, challenges remain, such as the unclear thermal and nonthermal contributions, which limit mechanistic understanding and catalyst design. Insufficient insight into energy transfer, deactivation, and local reaction environments also hinders the efficiency. Practical issues, such as stability, light penetration, heat control, and scalability, limit industrial use. Future research should integrate operando characterization, modeling, and machine learning to understand the structure–performance relationships and develop efficient catalysts. Photothermal CO2 conversion is advancing rapidly, with the potential for carbon-neutral energy production through efficient solar-driven catalytic processes.