Synergistic Effect of the V₂CT_x MXene@V₂O₅/TiO₂ NP Composite for Stimulating Photocatalytic CO₂ Reduction through Bireforming of Methanol to Produce CO and CH₄

Abstract

Vanadium carbide (V2C) MXene, a transition metal, exhibits significant potential as an innovative cocatalyst to enhance photocatalytic efficiency. In this study, we explored the construction of a self-assembled V2C@V2O5/TiO2 composite through the sol–gel method, incorporating in situ grown vanadium oxide (V2O5) with TiO2. Efficient charge carrier separation was achieved owing to the higher conductivity, abundant active sites, and higher light absorbance. When V2C@V2O5/TiO2 was employed with a methanol–water mixture, the resulting CO and CH4 production reached remarkable amounts of 20 075 and 17 567 μmol g–1 h–1, respectively. This represented a substantial enhancement in photocatalytic efficiency compared to using water/H2 sacrificial reagents and pure TiO2 nanoparticles. This enhanced photoactivity in the presence of methanol was attributed to efficient photoinduced carrier separation, facilitated by the synergistic effect of V2C/V2O5 and increased proton production. Moreover, the performance of the V2C MXene-based composite for CO, CH4, and H2 formation was 1.45, 52.75, and 1.35 times higher, respectively, than that achieved with the V2AlC MAX-based TiO2 composite. The advantages of V2C conductivity and its two-dimensional layered structure contributed to achieving higher photocatalytic efficiency compared to using the MAX structure. The maximum quantum yield of 9.7, 8.488, and 0.352% for CO, CH4, and H2, respectively, was achieved over the V2C@V2O5/TiO2 composite with continuous photoactivity with consecutive cycles. This study not only demonstrates the promising prospects of V2C MXenes but also introduces an innovative approach for designing and fabricating highly efficient and stable photocatalytic systems for CO2 recycling, with potential applications in various energy-related fields.

Review and Perspectives on Preparation Strategies and Applications of Ti3C2 MXene for Li Metal Batteries/Li–S Batteries

“…(3) With the deepening understanding and mastery of MXene by researchers, it has promoted the development and application of this material in other fields. In recent years, MXene has also been applied in flexible electronic devices, supercapacitors, electrocatalysis, biosensors, and flexible frictional nanogenerators, among other fields. − The field of flexible electronics involves many industries and has profound significance for the development of society. Developing flexible and high-performance flexible electronic products has become the main goal of future scientific research.…”