Piezocatalytic water purification: exploring the potential of perovskites in the current context

This review presents a comprehensive and futuristic analysis of perovskite-based piezocatalysis, a promising non-invasive strategy to generate reactive oxygen species for pollutant degradation, pathogen inactivation, and CO₂ reduction by utilizing mechanical stimuli. This work differs from the previous reviews in that it systematically studies the fundamental mechanisms of piezocatalysis, including the energy band theory, screening charge effect, and quantization of piezoelectricity. They are related to the piezoelectric coefficient, polarization rotation, domain engineering, and phase transitions in perovskites. Particular attention has been paid to lead-free perovskites, polymer composites, double perovskites, layered Ruddlesden-Popper phases, chalcogenide and halide perovskites, and heterostructures, with a focus on their roles in improving environmental safety, scalability, and catalytic activity. Integration with photocatalysis is proposed as a promising strategy to further improve the piezocatalytic performance. Moreover, a cyclonic piezoelectric reactor is preliminarily designed as a forward-looking solution for industrial-scale applications, with enhanced mass transfer and mechanical energy coupling. In addition, this review provides a unique perspective on the complexities of the real world, including contaminant diversity, pH variability, and long-term operational stability. This work serves as a critical blueprint to accelerate piezocatalytic water purification toward sustainable and translational applications in environmental and biomedical fields via key knowledge gaps and material design strategies.