Design of cobalt-based catalysts with the uniformly distributed core-shell structure for ultra-efficient activation of peroxymonosulfate for tetracycline degradation
Hongjie Qin, Weijie Zhang, Qiling Zheng, Penghui Zhang, Shouwei Zhang, Xijin Xu
Abstract
Catalysts that can rapidly degrade tetracycline (TC) in water without introducing secondary ion pollution have always been challenging. Herein, a cobalt-based catalyst (CoOx@P-C) is prepared so that CoOx quantum particles (5–10 nm) are uniformly distributed on a linear substrate, and the outer layer is covered with a shell (P-C). The quantum particles of CoOx provide many active sites for the reaction, which ensures the efficient degradation effect of the catalyst, and 30 mg/L TC can be completely degraded in only 5 min. The shell of the quantum particles' outer layer can effectively reduce ions' extravasation. The combination of the shell-like structure and the linear substrate greatly enhances the catalysis's stability and ensures that the catalyst is prepared into a film for practical application. The high catalytic activity of CoOx@P-C is mainly due to the following factors: (1) Uniformly distributed ultra-small nanoparticles can provide many active sites. (2) The microenvironment formed by the core-shell structure enhances not only catalytic stability but also provides the driving force to improve the reaction rate. (3) The composite of CoOx and P-C core-shell structure can accelerate electron transfer and generate many reactive oxygen species in a short time, which makes TC degrade extremely rapidly.