State‐Of‐The‐Art Structural Regulation Methods and Quantum Chemistry for Carbon‐Based Single‐Atom Catalysts in Advanced Oxidation Process: Critical Perspectives into Molecular Level

Abstract Advanced oxidation processes (AOPs) by carbon‐based single‐atom catalysts (SACs) are recognized as an attractive scientific frontier for water treatment, with the outstanding benefits of ultra‐effective and anti‐interference capability. However, most of the research has paid more attention to the performance of SACs, while the in‐depth understanding of catalytic regulation by molecular interaction is relatively deficient. This critical review delves into deciphering the catalytic mechanism through a micro‐level, which makes it more convenient to interpret apparent catalytic phenomena. It first summarizes basic theories of quantum chemistry, which provide mechanism interpretation and prediction for molecular‐oxidation systems. Additionally, corresponding oxidation pathways of common oxidants are underscored. Following the oxidants, state‐of‐the‐art regulation methods are discussed with special attention to involved molecular interactions and pollutants. Particularly, the preliminary insights into the “oxidant‐catalyst‐pollutants” internal relationships are provided to help construct the SAC‐AOP system from a molecular standpoint. Meanwhile, some cutting‐edge laboratory devices and pilot‐scale engineering are presented to illustrate the ultimate purpose of scientific molecular exploration. Eventually, relative challenges of SACs‐AOPs upon the design of catalytic systems and investigation methods are provided. This review aims to promote the large‐scale potential of SACs‐based AOPs in practical water treatment by emphasizing the pivotal role of micro‐insights.