Progressive MXene-based photocatalytic and electrocatalytic sustainable reduction of CO2 to chemicals: comprehensive review and future directions

To reverse the impact of CO2, it is necessary not only to curb the dependence on fossil fuels but also develop effective strategies to capture and utilize CO2 in the atmosphere. However, the solar-to-chemical efficiency for the reduction of CO2 using photocatalysts is not satisfactory in practical applications due to their poor adsorption and activation of CO2, rapid recombination of photogenic charge carriers, and deactivation of their surface sites. Thus, herein, we aim to concisely summarize the state-of-the-art development of 2D-MXene-based photocatalysts for CO2 reduction. First, we briefly introduce the mechanism for the photocatalytic reduction of CO2. Second, the synthesis and properties of MXene composites are summarized together with their role in electrochemical photocatalytic CO2 reduction. Third, various types of MXene-based photocatalysts such as MXene/metal oxide, MXene/nitride, MXene/perovskite, MXene/LDH, and MXene-based photocatalytic CO2 reduction photocatalysts are classified and shown. Finally, we present the related challenges and perspectives on MXene-based photocatalysts.