Review of Piezocatalysis and Piezo-Assisted Photocatalysis in Environmental Engineering

In light of external bias potential separating charge carriers on the photocatalyst surface, piezo materials' built-in electric field plays a comparable role in enhancing photocatalyst performance. The synergistic effect provided by combining piezo materials assures the future of photocatalysis in practical applications. This paper discusses the principles and mechanisms of piezo-photocatalysis and various materials and structures used for piezo-photocatalytic processes. In piezo-photocatalyst composites, the built-in electric field introduced by the piezo component provides bias potential and extracts photocatalytically generated charge carriers for their subsequent reaction to form reactive oxygen species, which crucially affects the catalytic performance. In the composites, the shape and structure of substrate materials particularly matter. The potential of this technology in other applications, such as energy generation and environmental remediation, are discussed. To shed light on the practical application and future direction of the technique, this review gives opinions on moving the technique forward in terms of material development, process optimization, pilot-scale studies, comprehensive assessment of the technology, and regulatory frameworks to advance practical applications, and by analyzing its principles, applications, and challenges, we hope to inspire further research and development in this field and promote the adoption of piezo-photocatalysis as a viable treatment method for treating emerging pollutants in wastewater.