Titanium carbide MXene with out-of-plane electromechanical response as substrate of molybdenum disulfide for enhanced piezocatalysis

As an emerging two-dimensional material, MXene has been widely used in electrocatalysis, photocatalysis and other fields, which is expected to play a huge role in the field of piezocatalysis due to its high conductivity. In this work, titanium carbide MXene loaded with molybdenum disulfide (Ti3C2 @MoS2) was prepared by growing MoS2 vertically on the surface of Ti3C2 MXene to expose more marginal active sites. In addition, the high conductivity of Ti3C2 can accelerate the free carrier transfer and enhance the piezoelectric response, thus boosting the piezocatalytic activity. Among them, the optimal Ti3C2 @MoS2-7 established excellent piezocatalytic activity of bisphenol A (BPA) degradation and hydrogen evolution, and the corresponding rate constant was 0.095 min−1 and 197.3 μmol·g−1·h−1, which was 4.1 times and 5.9 times of MoS2, respectively. In addition, Ti3C2 exhibited a catalytic activity higher than that of the classical piezoelectric semiconductor MoS2 under the ultrasonic, and the possible origins were speculated by piezoelectric force microscope and free radical detection. It demonstrates a great application potential of MXene and MXene-based nanomaterials in piezocatalysis, providing a feasible strategy for the design of piezocatalysts.