Recent Progress of Studies on Photoconversion and Photothermal Conversion of CO2 with Single-Atom Catalysts.

Catalytic conversion of carbon dioxide (CO2) into useful chemical raw materials or fuels can help achieve the "dual carbon" goals of carbon peaking and carbon neutrality. As a sustainable green energy source, solar energy provides energy for human production and life. In recent years, the reported single-atom catalysts (SACs) have higher atom utilization and better catalytic efficiency than traditional heterogeneous catalysts. In the field of photocatalysis and photothermal synergistic catalysis of CO2 conversion, single-atom catalysts can reduce the reaction temperature and pressure, improve the catalytic activity, and improve the selectivity of the reaction. In this mini-review, the basic mechanism and classification of CO2 reduction are introduced, and then the roles and differences of single-atom catalysts in photocatalysis and photothermal catalysis are introduced. In addition, according to the reduction product types, the recent research progress of single-atom catalysts in photoconversion and photothermal CO2 conversion was reviewed. Finally, the challenges of monoatomic photocatalytic and photothermal CO2 reduction technologies have prospected. This mini-review hopes to provide an in-depth understanding of the roles of single atoms in photocatalysis and photothermal catalysis and to shed light on the actual production and application of renewable energy. High-performance single-atom catalysts are expected to achieve industrial applications of CO2 conversion, which will contribute to the early realization of the two-carbon goal.