Chainmail catalysis for advanced water treatment: overcoming the stability–reactivity tradeoff in Fenton-like oxidation of micropollutants

Recent developments in chainmail catalysis present a promising solution to the longstanding challenge of catalytic deactivation in traditional advanced oxidation processes (AOPs) for water reuse. This strategy involves encapsulating nanocatalysts within protective carbon shells, which significantly improves their stability and enhances the degradation kinetics of micropollutants. The unique architecture of these materials promotes efficient electron transfer between the transition metal core and the surrounding carbon matrix, giving rise to a range of intriguing and unprecedented phenomena. Given its strong potential, this review provides a comprehensive overview of the latest developments in chainmail catalysis, highlighting its advantages over conventional AOPs. This review critically examines experimental results, theoretical insights, and conflicting observations related to the generation of reactive species and degradation mechanisms of micropollutants. The influence of key parameters (such as catalyst structure and activity, carbon shell morphology and thickness, heteroatom doping, surface functionalization, and the composition and redox state of the metal core) on chainmail catalytic performance is also thoroughly analyzed. Furthermore, the review assesses the practical viability of chainmail catalysis in real-world water treatment applications by examining the impact of operating conditions and water matrices on chainmail catalytic performance. Finally, this review outlines key technological challenges and proposes a roadmap to guide future research and the practical implementation of chainmail catalysis for efficient removal of micropollutants.