Construction of MXene/Bi<sub>2</sub>WO<sub>6</sub> Schottky Junction for Highly Efficient Piezocatalytic Hydrogen Evolution and Unraveling Mechanism
Xueer Ning, Aize Hao, Yali Cao, Ruqi Chen, Jing Xie, Zhenjiang Lu, Jindou Hu, Dianzeng Jia
Abstract
For the first time, a series of MXene (Ti 3 C 2 T x )/Bi 2 WO 6 Schottky junction piezocatalysts were constructed, and the piezocatalytic hydrogen evolution activity was explored. Optimal Ti 3 C 2 T x /Bi 2 WO 6 exhibits the highest piezocatalytic hydrogen evolution rate of 764.4 μmol g –1 h –1, which is nearly 8 times higher than that of pure Ti 3 C 2 T x and twice as high as that of Bi 2 WO 6 . This value also surpasses that of most recently reported typical piezocatalysts. Moreover, related experimental results and density functional theory calculations reveal that Ti 3 C 2 T x /Bi 2 WO 6 can provide unique channels for efficient electron transfer, enhance piezoelectric properties, optimize the adsorption Gibbs free energy of water, reduce activation energy for hydrogen atoms, endow robust separation capacity of charge carrier, and restrict the electron–hole recombination rate, thus significantly promoting the efficiency of hydrogen evolution reaction. Ultimately, we have unraveled an innovative piezocatalytic mechanism. This work broadens the scope of MXene materials in a sustainable energy piezocatalysis application.