Recent progress of MXene as a cocatalyst in photocatalytic carbon dioxide reduction

Due to the excessive consumption of fossil fuel resources and the emission of a substantial quantity of CO2 into the environment, it is urgent to develop clean energy solutions. In order to reduce carbon emissions from the source, it is effective approach to convert CO2 into various renewable energy fuels. Inspired by the photosynthesis of green plant, CO2 is converted into clean fuel with the aid of catalysts. Regarding the separation and transfer of photogenerated charge carriers, and inadequate adsorption and activation of CO2 on the surface of catalysts, the current semiconductors utilized in photocatalysis have low efficiency. As a result, the current efficiency of photocatalysts is far from meeting the need for practical industrial demands. MXene materials, for example Ti3C2Tx (9980 S cm-1), have emerged as a promising candidate for CO2 reduction due to the significant number of active sites for functional groups, high conductivity and low defects, large surface areas, and outstanding visible light photoelectronic properties. This review provides a critical overview of the recent progress regarding MXene as a co-catalyst in photocatalytic CO2 reduction systems. We systemically explore the fundamental principles and reaction mechanisms associated with separating and transferring photogenerated charge carriers. Additionally, we investigate the basic properties of MXene as a co-catalyst in the context of CO2 reduction. Furthermore, this review also elucidates the impacts of the microstructure of photocatalysts on enhancing photocatalytic performance. Finally, the challenges and opportunities in using MXene as a co-catalyst for CO2 reduction have been presented to inspire further research in this field.