Boosted CO2 photoreduction performance on Ru-Ti3CN MXene-TiO2 photocatalyst synthesized by non-HF Lewis acidic etching method

Photocatalytic CO 2 reduction to produce value-added products is considered a promising solution to solve the global energy crisis and the greenhouse effect. In this study, Ti 3 CN MXene was synthesized using a Lewis acidic etching method without the usage of toxic hydrofluoric acid (HF). Ti 3 CN MXene was then used as a support for the in situ hydrothermal growth of TiO 2 and Ru nanoparticles. In the presence of 0.5 wt% Ru, Ru-Ti 3 CN-TiO 2 shows CO and CH 4 production rates of 99.58 and 8.97 μmol/g, respectively, in 5 h under Xenon lamp irradiation, more than 20.5 and 9.3 times that of commercial P25. The enhancement in photocatalytic activity was attributed to the synergy between the in-situ growth of TiO 2 on Ti 3 CN MXene and Ru nanoparticles. It was proven experimentally that Ti 3 CN MXene can provide abundant pathways for electron transfer. The separation and transfer of the photo-induced charge were further increased with the help of Ru and Ti 3 CN MXene, leaving more electrons to participate in the subsequent CO 2 reduction reaction. We believe that this work will encourage more attention to designing environment-friendly MXene-based photocatalysts for CO 2 photoreduction using the non-HF method.