MXene-derived quantum dots based photocatalysts: Synthesis, application, prospects, and challenges

In recent years, the emerging two-dimensional material-MXenes has attracted widespread attention in the field of photocatalysis due to its high conductivity, suitable Fermi level, tunable elemental composition, and excellent photoelectric properties. The zero-dimensional quantum dots (MQDs) derived from 2D MXenes not only inherit the characteristics of MXenes but also exhibit better performance due to the quantum size effect. Based on the above excellent physical and chemical properties, MQDs are often used as co-catalysts of photocatalysts, and show excellent co-catalytic properties. At the same time, compared with other cocatalysts (precious metals, metal oxides, metal sulfides), it has the advantages of low cost and high conductivity. Therefore, understanding the status of MQDs in the field of photocatalysis is crucial for their further development. In this review, we summarized the synthesis and modification methods of MQDs in recent years, as well as their photocatalytic applications in H2 production, CO2 reduction, N2 fixation, pollutant degradation, and other aspects. In addition, the challenges and prospects faced by MQDs are also proposed, providing theoretical guidance for the further development of MQD-based photocatalysts.