Single atom Co-anchored nitrogen‑doped graphene for peroxymonosulfate activation with high selectivity of singlet oxygen generation

Singlet oxygen (1O2) is an excellent active species generated in advanced oxidation processes (AOPs) that exhibits high selectivity, long life and wide pH tolerance. Therefore, catalysts for highly efficient and selective generation of 1O2 in AOPs would be highly desirable. This study developed a single atom Co-anchored nitrogen‑doped graphene (CoSAC-NG), which showed excellent catalytic performance for peroxymonosulfate (PMS) activation and bisphenol A degradation, with the pseudofirst-order reaction rate constant improved from 8.13 × 10−4 min−1 without catalyst to 4.42 × 10−2 min−1 with 5 mg L−1 CoSAC-NG. Mechanism studies indicated that CoSAC-NG selectively enhanced 1O2 generation, which was the dominant active specie for pollutant degradation. Moreover, the CoSAC-NG/PMS system effectively reduced the acute toxicity of pollutant, and CoSAC-NG exhibited remarkable cycling stability and negligible leaching. This study develops a new catalyst with high selectivity for 1O2 generation and provides a reference for application of single atom catalyst in PMS-based AOPs.