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

Photocatalytic CO2 reduction to produce value-added products is considered a promising solution to solve the global energy crisis and the greenhouse effect. In this study, Ti3CN MXene was synthesized using a Lewis acidic etching method without the usage of toxic hydrofluoric acid (HF). Ti3CN MXene was then used as a support for the in situ hydrothermal growth of TiO2 and Ru nanoparticles. In the presence of 0.5 wt% Ru, Ru-Ti3CN-TiO2 shows CO and CH4 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 TiO2 on Ti3CN MXene and Ru nanoparticles. It was proven experimentally that Ti3CN 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 Ti3CN MXene, leaving more electrons to participate in the subsequent CO2 reduction reaction. We believe that this work will encourage more attention to designing environment-friendly MXene-based photocatalysts for CO2 photoreduction using the non-HF method.