Titanium Carbide (Ti3C2) MXene as a Promising Co-catalyst for Photocatalytic CO2 Conversion to Energy-Efficient Fuels: A Review

Photocatalytic CO 2 reduction to produce valuable chemicals and fuels using solar energy provides an appealing route to alleviate global energy and environmental problems. However, available semiconductor materials are less efficient to promote CO 2 conversion to energy-efficient fuels. In the current development, titanium carbide (Ti 3 C 2 ) MXene as a co-catalyst with a high conductivity, abundant active sites, and large specific surface area, is a preeminent candidate to promote semiconductor photoactivity. This review provides an overview in the utilization of Ti 3 C 2 as a promising co-catalyst for maximizing CO 2 reduction efficiency and product selectivity. In the mainstream, developments in Ti 3 C 2 MXene-based composites for CO 2 conversion through different processes, such as CO 2 reduction with water, photocatalytic CO 2 methanation, and natural gas flaring reduction to synthesis gas, have been discussed. The review also gives an overview of the factors crucial to affect photocatalytic properties of Ti 3 C 2, such as morphological, electrical, optical, and luminescence characteristics. The fundamental mechanism of Ti 3 C 2 T x for photocatalytic reduction of CO 2 and strategies to improve the photocatalytic performance are also described. The great emphasis is given on in situ TiO 2 production and hybridization with other semiconductors to obtain an efficient co-catalyst for selective CO 2 reduction. Lastly, conclusions and future prospectives to further explore in the field of energy and fuels are included.