Natural mineral modulated single atom catalyst for effective water treatment

Single atom catalysts (SACs) have been growing as an emerging “hot” topic in environmental remediation. Their performance can be rationally optimized via modulating spatial coordination configuration and porous structure of SACs, which is still challenging. Herein, a novel Si, N co-coordinated cobalt SACs (p-CoSi₁N₃@D) with 3D freestanding architecture was tailored via employing natural mineral (diatomite) as Si source and porous template. Theoretical calculations and experimental analysis reveal that Si substitution dramatically decreases electronegativity of CoN₄ moieties and thus accelerates interaction and electron transfer between peroxymonosulfate and Co single atom center. Moreover, p-CoSi₁N₃@D inherits hierarchically porous architecture of diatomite, providing more accessible cobalt sites and open diffusion channels for peroxymonosulfate and contaminants in water treatment applications. Thanks to optimal coordination structure and porous architecture, p-CoSi₁N₃@D can serve as highly active catalyst toward peroxymonosulfate activation, with a turn-over frequency of 299.8 min^{− 1} for bisphenol A degradation, surpassing those of catalysts with transition metal SACs or oxides in disclosed literature. This work provides a novel vision for development of SACs towards wastewater reclamation.