Cobalt single atom anchored at C2N3 for activating peracetic acid to ultrafast degrade drugs at 4 °C

Abstract

Low temperature weakens the catalytic degradation efficiency of contaminants in advanced oxidation processes. C2N3, a preeminent catalyst support material, was prepared by the pyrolysis of HNO3 pretreated melamine. The Co SA/C2N3 was prepared by the pyrolysis-induced-vaporization strategy, and used to activate peracetic acid (PAA) to degrade drugs. The Co SA/C2N3-650-2+PAA system can completely remove acyclovir within 3 min at 4 °C, and achieved excellent removal rate under the various influencing factors. The system showed outstanding degradation performance in repeated use experiment and simulated wastewater experiment. Co SA/C2N3-650-2 was cross-linked to the calcium alginate sponge, and exhibited superior practicability in microreactor experiment. The electron paramagnetic resonance (EPR), quenching experiment and density functional theory (DFT) calculations certificated that the non-radical pathway was primary mechanism in which 1O2 played a major role. The Co(Ⅱ)N3 sites and PAA bound to form Co(IV) by electron transfer, which attacked the external peroxygen of PAA to produce 1O2. This study proposes a novel pathway for the generation of 1O2 and provides an efficient SA catalyst for degradation of drugs in cold regions.