Emerging investigator series: recent progress on the activation of persulfate by vacancy defect materials: the role of vacancies

The utilization of persulfate (PS) as the cornerstone of advanced oxidation processes (AOPs) is an emerging and powerful method for eliminating persistent organic pollutants in wastewater. The efficient activation of PS is a prerequisite factor in this technology. Through the strategic application of vacancy defect engineering, catalytic materials can be optimized to improve PS activation. In this review, our exploration focuses on clarifying the key role of vacancy defects in promoting PS activation and summarizing the potential mechanisms of PS activation. In addition, six widely used advanced characterization techniques and density functional theory (DFT) calculations are introduced to characterize vacancies in materials. Furthermore, we systematically summarize the methods of vacancy generation and introduce common different types of vacancy defect catalytic materials and their applications. Finally, we summarize and present the enhancement of PS activation by vacancy defect materials. This review provides new insights for us to understand the mechanism of vacancy defect materials promoting PS activation and its future development, hoping to design more efficient catalysts in the future for environment remediation.