Enhancement of Carrier Migration by Monolayer MXene Structure in Ti3CN/TiO2 Heterojunction to Achieve Efficient Photothermal Synergistic Transformation of CO2

Carbon nitride MXene exhibits good metal conductivity, high photothermal conversion, carrier mobility, and high exposure of active sites, which makes it a promising co-catalyst for photothermal synergistic transformation of CO2. In this paper, Ti3CN/TiO2 heterojunction was constructed in situ using Ti3CN as TiO2 precursor to investigate the performance of Ti3CN MXene in photothermal synergistic transformation of CO2, and then the monolayer structure was utilized to enhance the interfacial charge transfer and improve the photothermal catalytic activity of Ti3CN. The catalysts were characterized by SEM, XRD, XPS, and UV-Vis DRS, and it was found the heterojunction constructed by monolayer MXene had a narrower bandgap and a higher carrier generation mobility, which, combined with the catalytic activity test, proved the single monolayer Ti3CN MXene had better photothermal synergistic conversion efficiency of CO2, and the heterojunction yield was 11.36 μmol·g−1·h−1 after layering, compared with that before layering (9.41%), which was 1.2 times higher than that before layering (9.41 μmol·g−1·h−1).