Piezocatalysis and Piezo-Photocatalysis: Catalysts Classification and Modification Strategy, Reaction Mechanism, and Practical Application

Piezoelectric-based catalysis that relies on the charge energy or separation efficiency of charge carriers has attracted significant attention. The piezo-potential induced by strain or stress can induce a giant electric field, which has been demonstrated to be an effective means for charge energy shifting or transferring electrons and holes. In recent years, intense efforts have been made in this subject, and the research has mainly focussed on two aspects: i) Alteration of surface charge energy by piezo-potential in piezocatalysis; ii) the separation of photo-generated charge carriers and the catalytic activity enhancement of an integrated piezoelectric semiconductor or coupled system composed of piezoelectrics and semiconductors. Systematically summarizing the advances of the above two aspects is helpful in the context of deepening understanding of the relevant issues and developing new ideas for piezoelectric-based catalysis. In this review, a comprehensive summary on piezocatalysis and piezo-photocatalysis is provided. The charge transfer behaviors and catalytic mechanisms over a large variety of piezocatalysts and piezo-photocatalysts are systematically analyzed. In addition, the types of mechanical energy, strategies for enhancing piezocatalysis, and the advanced applications of piezocatalysis and piezo-photocatalysis are discussed. Finally, the promising development directions of piezocatalysis and piezo-photocatalysis, such as materials, assembly forms, and applications in the future are proposed.