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.