Spontaneous reduction of copper on Ti3C2Tx as fast electron transport channels and active sites for enhanced photocatalytic CO2 reduction

Abstract

Graphitic carbon nitride (g-C3N4) is regarded as a promising photocatalyst for photocatalytic CO2 reduction into valuable solar fuels. In this work, Cu-Ti3C2Tx was used as efficient cocatalysts to enhance the photocatalytic performance of g-C3N4. The tight interface between Cu-Ti3C2Tx and g-C3N4 significantly promote the separation of photogenerated electrons and holes. In addition, the Cu and the Ti3C2Tx can act as the fast transport channels for the photogenerated electrons, and the interface between the Cu and Ti3C2Tx can act as the active sites for the adsorption and activation of CO2. The optimized Cu-Ti3C2Tx/g-C3N4 exhibited the highest photocatalytic CO2 reduction performance with the yield of CO and CH4 reached 49.02 and 3.6 μmol·g−1, respectively, which was 9.0 and 9.2 times than that of pristine g-C3N4. Moreover, the optimized Cu-Ti3C2Tx/g-C3N4 photocatalyst maintained satisfactory stability. This work will offer new insight into modulating g-C3N4 with an MXene-metal-based cocatalyst for photocatalytic CO2 reduction.