Abstract:
Under the combined push of global climate governance and the “dual-carbon” goal, research on CO
2 catalytic conversion has attracted great attention. In recent years, photothermal catalysis, as an emerging catalytic technology, can not only enhance the utilization of solar energy but also convert light energy into heat, increasing the reaction temperature and combining the advantages of both photocatalysis and thermocatalysis. Therefore, it has become one of the research hotspots for CO
2 hydrogenation reactions. However, photothermal catalytic CO
2 hydrogenation still faces challenges such as low catalyst activity, limited photothermal efficiency, and difficulty in controlling product selectivity. Furthermore, the main selective products of traditional catalysts are C
1 compounds, and the formation of C
2+ products involves complex C—C coupling processes that require overcoming high kinetic barriers, resulting in generally low selectivity for C
2 products by conventional catalysts. Therefore, developing catalysts with high activity, high selectivity and photothermal stability is the key to achieving the targeted conversion of CO
2 into C
2 products. A series of MoS
2 catalysts composed of three-dimensional flower-like microspheres self-assembled from ultrathin nanosheets were synthesized by hydrothermal method through regulating the mass ratio of sulfur source and molybdenum source in the precursor. Among them, the MoS
2-1.5 catalyst achieved a C
2H
6 selectivity of 69.2% and a production rate of 253.66 μmol/(g·h) under 1.2 W/cm
2 light irradiation. Meanwhile, the research results confirmed that by regulating the light intensity and extending the light exposure time, the CO
2 conversion rate and ethane selectivity could be effectively enhanced. Through comparison with thermal catalysis, the significant advantages of higher CO
2 conversion efficiency and product selectivity under photothermal catalysis conditions were highlighted. The excellent stability of MoS
2 demonstrated the unique advantages of two-dimensional sulfides in carbon chain growth reactions, providing a new idea for designing photothermal catalysts that can convert CO
2 into high-value chemicals under mild conditions.