Strategies on enhancing piezocatalysis performance of ZnO-based catalysts for aquatic pollutants degradation: A review

Piezocatalysis that brings the conversion from mechanical energy to chemical energy has caught more and more attention of researchers in the field of wastewater treatment, due to its advantages of environmental friendliness and sustainability. In particular, Zinc oxide (ZnO) is regarded as an appropriate candidate material for the piezocatalytic degradation of aquatic pollutants because of the merits such as low-cost, non-toxicity and remarkable electron mobility. Besides, wurtzite ZnO possesses unique piezoelectricity owing to its noncentrosymmetric structure, which is constituted by alternating planes of Zn²⁺ and O^2- ions along the c-axis, each Zn²⁺ being tetrahedral with four surrounding O^2-, and vice versa. Nevertheless, the piezocatalytic performance of pure ZnO is unsatisfactory which greatly hinders its practical application. So numerous strategies are used to enhance its piezocatalytic activity. This review roundly sums up the strategies for the enhancement of ZnO-based piezocatalysis performance. Furthermore, current challenges and future perspectives of ZnO-based piezocatalysis are proposed, which would be conducive to the design and development of more serviceable ZnO-based piezocatalysts in the future.