Co/N co-doped porous carbon as a catalyst for the degradation of RhB by efficient activation of peroxymonosulfate.

We report on the preparation of Co/N-NPCx/y with porous structure and excellent activation properties. The synthesis involves the preparation of Zn/Co-ZIFx and the carbonization of Zn/Co-ZIFx at a high temperature in an inert atmosphere. The volatilization of zinc during carbonization results in a porous structure, which is beneficial to the migration of pollutants. The sizes, specific surface areas, and pore size distribution of Co/N-NPCx/y can be achieved by tuning Zn/Co ratio. The calcination temperatures mainly affect the crystalline phase, crystallinity, and magnetic properties of the as-prepared materials. The effects of the as-prepared materials properties and activation conditions on the Rhodamine B (RhB) degradation by PMS activation were investigated. Overall, it exhibited superior catalytic activity in PMS activation, as evidenced by almost complete removal of RhB (0.020 mM, 100 mL) by using 5 mg/L Co/N-NPC0.5/900 and 1.250 mM PMS within 30 min. Furthermore, it confirmed the participation of SO4•-, •OH, and 1O2 in the catalytic reaction, and both SO4•- and 1O2 were the main reactive oxygen species that play a major role.