Stabilizing atomic Co on 2D ordered mesoporous carbon sandwiched MXene for peroxymonosulfate activation: Enhanced performance and electron-transfer mechanism

In this study, a dual-carrier catalyst is designed for efficient Fenton-like catalysis following non-radical electron-transfer process (ETP). By using 2D mesoporous carbon sandwiched MXene (MCSMx) nanosheets as dual functional substrates, Co single atoms (Co-SA) were confined within MCSMx (Co-SA/MCSMx), in which the coordinated Co-N-4 sites in highly ordered mesoporous channels (similar to 10 nm) facilitated the adsorption of peroxymonosulfate (PMS), while the excellent conductivity of MXene as the substrate enhanced the transport of electron. The unique design of Co-SA anchored on dual carriers endows the Co-SA/MCSMx with excellent PMS adsorption and rapid electron transfer, achieved nearly 100 % ETP pathway for bisphenol A (BPA) removal and highly selective degradation towards electron-rich pollutants. Moreover, the ETP-induced polymerization transfer reaction of BPA was discovered in the catalytic system, resulting in total organic carbon (TOC) removal ratios of up to 72 %. This work provides new insights into the rational design ETP-based systems for the efficient removal of organic pollutants.