Accelerating peroxymonosulfate-based Fenton-like reaction via Mott-Schottky heterojunction.

A Mott-Schottky heterojunction is reported to boost the peroxymonosulfate (PMS) activation in Fenton-like reaction through a non-radical path. The heterojunction with Co nanoparticles encapsulated by nitrogen-doped graphitized carbon (N-GC) shell was synthesized via pyrolysis of ZIF67 @ZIF8 and subsequent acidic treatment. Benefiting from Mott-Schottky effect, the electrons were transferred from Co nanoparticles to the N-GC shell, leading to the rearranged electron density on N-GC surface and improvement of the PMS activation. The PMS activation efficiency of heterojunction (86.0%) was much higher than the reference catalyst without Mott-Schottky effect (35.3%), and even comparable to Co2+ (86.2%). 85.0% of tetracycline (TC) removal efficiency was realized after only 10.0 s. Moreover, the intrinsic advantages of non-radical path were well inherited by Mott-Schottky heterojunction, including high anti-interfere property toward various anions, cations and organics, high catalytic activity in a wide pH range, low metal leaching, and high magnetic recyclability. [Display omitted] • Electrons flow from Co NPs to N-GC and arranged in Mott-Schottky heterojunction. • PMS activation efficiency is comparable to Co2+ and 85.0% of TC is removed at 10 s. • Electrons play crucial role among ROSs, and PMS activation follows non-radical path. • Mechanism of Mott-Schottky effect on enhanced degradation performance is revealed. • EP-ZIF67 @ZIF8 is high environmental adaption, wide applicable pH, low leaching. [ABSTRACT FROM AUTHOR]