Activation of peroxymonosulfate/persulfate by nanomaterials for sulfate radical-based advanced oxidation technologies

Sulfate radical anion (SO4 center dot-) based advanced oxidation technologies (AOTs) have received a great deal of attention due to their high reactivity with the organic contaminants and high selectivity in complex environmental matrices. Among all SO4 center dot- activation techniques, the heterogeneous activation of precursor peroxides such as peroxymonosulfate (PMS) and persulfate (PS) by nanostructured materials has demonstrated to be an effective method to generate SO4 center dot-. This paper reviews SO4 center dot- chemistry and the nanostructured materials that can effectively activate PMS/PS, namely, transition metal-based nano-catalysts, carbon nanomaterials, and nano-composites. In addition, we also discuss the activation mechanisms of PMS/PS initiated by heterogeneous nanostructured materials, emphasizing their catalytic activity, stability, and reusability for the removal of organic contaminants. This review shows that nanostructured materials have promising potential in environmental remediation based on their excellent catalytic efficiency, large specific surface area, and controllable structure. It also provides perspective on potential future studies on the design of novel nanostructured materials and process development in the field of SO4 center dot- based AOTs.