Photocatalytic and electrocatalytic reduction of CO2 and N2 by Ti3C2 MXene supported composites for a cleaner environment: A review

Simultaneous benefits of useful energy-rich hydrocarbon fuel generation and the decline of global warming can be appreciably achieved by photocatalytic CO2 reduction. In this contribution, a series of modifications in Ti3C2 MXene morphology have been made in boosting CO2 adsorption, activation, and reduction due to their high surface functionality. In this regard, we compiled three classes of Ti3C2 MXenes in the form of multilayer, monolayer, and quantum dots about profundity realizing of CO2 reduction under direct CO2 gas injection and in situ CO2 generation during the reaction process. By featuring basicity of –OH surface functional groups, primary figures of merits such as CO2 adsorption, CO2 selectivity, charge carrier separation, and resultant work function have been controlled. Thus, rational engineering of state-of-the-art Ti3C2–OH MXene based composites prevailed fruitful carbon monoxide, methane, and methanol generation. We have overviewed optimization of appropriate matching interaction between conduction band potential of the developed catalyst and reduction potential of respective hydrocarbon fuel. We further explored photocatalytic and electrocatalytic N2 reduction of Ti3C2 MXene for carbon-free ammonia generation under ambient conditions. In the mainstream, suppressed hydrogen evolution is highlighted during N2 reduction at less negative potentials. Overall, various Ti3C2 MXene supported composites garnered a lot of interest in CO2 and N2 reduction for a sustainable clean society. Finally, this review summarized the challenges and future perspectives.