Enhanced peroxymonosulfate-based Fenton-like degradation performance by confined radical activation path and non-radical activation path inside yolk@shell nanoreactor.

In peroxymonosulfate (PMS)-based Fenton-like reaction, there were two pathways for PMS activation: radical path on transition metal surface and non-radical path on heteroatom-doped carbon surface. In this work, CoS 2 /nitrogen-atom doped carbon (NC)@SiO 2 yolk@shell nanoreactor was designed, on CoS 2 /NC surface, these two paths performed parallelly inside the nanoreactor, leading to an accelerated tetracycline degradation rate. 90.9% of removal efficiency was realized within 15 min, much higher than the reference samples, and the advantages of yolk@shell nanoreactor were illustrated in detail. Moreover, benefiting from the SiO 2 shell protection, the leached cobalt ion was only 0.27 mg/L, which was 1/20 of the reference CoS 2 /NC without SiO 2 shell. During the mechanism study, the two activation paths were identified by electron paramagnetic resonance tests, radical trapping experiments and electrochemical tests, where the SO 4 •- and 1O 2 were responsible for tetracycline (TC) degradation. This study provided a new strategy to simultaneously accelerate radical activation path and non-radical activation path by using the yolk@shell nanoreactor, and it might inspire other high efficient catalyst design for PMS-based Fenton-like reaction. [Display omitted] CoS 2 /NC@SiO 2 yolk@shell nanoreactor with CoS 2 /NC nanoparticles encapsulated inside the SiO 2 shell was prepared as a catalyst in Fenton reaction. • Radical and non-radical PMS activation paths are confined in CoS 2 /NC@SiO 2 nanoreactor. • Removal rate of CoS 2 /NC@SiO 2 is 3.6×10−2 L·min·mg−1, better than reference samples. • Co3+/2+ leaching is lowered to 0.27 mg/L due to the SiO 2 shell protection. • SO 4 •- and 1O 2 are responsible for TC degradation, and catalytic mechanism are studied. • Nanoreactor shows good versatility, recyclability, and anti-interference ability. [ABSTRACT FROM AUTHOR]