Co single-atom confined in N-doped hollow carbon sphere with superb stability for rapid degradation of organic pollutants

Single-atom catalysts (SACs), which have great potential in the field of water environmental remediation. Development of highly efficient SACs with sufficient stability and excellent catalytic performance was highly desirable, yet remains a huge challenge. Herein, a CoSA/NHCS catalyst was prepared by confining Co single-atom into the N-doped Hollow Carbon Sphere (NHCS) to activate peroxymonosulfate (PMS) for removing bisphenol A (BPA). Experimental and density functional theory (DFT) studies show that the combination of Co-N4 active site and electron transfer mechanism could achieve rapid degradation of BPA (98 % within 1 min). The main active sites of BPA attacked by the electron transfer pathway were predicted by calculating BPA molecular orbitals and Fukui indices. The possible degradation intermediates of BPA were identified by LC-MS and demonstrated to be nontoxic using ecological structure activity relationship modeling (ECOSAR). In a flow-through device for BPA degradation reaction, no deactivation of the catalyst was seen after 60 h and still remained 90 % remove efficiency after 100 h, which further renders it promising for actual water environmental remediation.