Waste Eggshell-derived N, P, S Tri-doped Core-shell Catalysts for Efficient Fenton-like Catalysis

Heteroatom-doped carbon materials have been proved as potent catalysts for the remediation of organic contaminants. Herein, molten salt electrolysis (MSE) was employed to convert waste eggshell and Co3O4 into N, P, S tri-doped core–shell catalyst ([email protected]), achieving the conversion of waste eggshell into value-added materials. Impressively, [email protected]/peroxymonosulfate (PMS) system exhibited an exceptional ultra-high turnover frequency (TOF) value of 83.86 min−1 for sulfamethoxazole (SMX) degradation with a low catalyst dosage of 0.001 g L–1. Subsequently, density functional theory (DFT) simulation clarified the synergistic essences of catalytic oxidation (i.e., the [email protected] catalyst reduced the adsorption energy of PMS molecular on its surface, reduced itself work function, enhanced the length of the O-O bond (IO-O) of PMS molecule, and facilitated electron transfer for PMS activation). In addition, both theoretical predictions and acute toxicity assay results indicated that the degradation of SMX equals detoxification. This work provides a new insight into the reutilization of waste eggshell and the design of heteroatom-doped core–shell catalysts.