Enhancement of Carrier Migration by Monolayer MXene Structure in Ti 3 CN/TiO 2 Heterojunction to Achieve Efficient Photothermal Synergistic Transformation of CO 2.

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). [ABSTRACT FROM AUTHOR]