The simplest and ultrafast microwave-mediated solid-state construction of cobalt oxide/carbon hybrid as an efficient peroxymonosulfate activator for ciprofloxacin degradation

Abstract

Development of facile, ultrafast, and solid-state strategy for one-step loading of metallic oxide on the carbon surface for the degradation of organic pollutants is desirable but remains a challenge. Herein, we develop a microwave-engaged solid method to synthesize carbon black supported Co3O4 composite (Co3O4/CB) for degradation of ciprofloxacin (CIP) via activating peroxymonosulfate (PMS). The simple microwave irradiation for a short time induces the decomposition of Co precursor to Co3O4 and subsequent its attachment on the CB surface. Noticeably, the Co3O4/CB-50 prepared by microwave irradiation for 50 s exhibits an excellent degradation performance for activating PMS to remove CIP (20 mg/L) with a removal rate of 95 % in 30 min. The crystal structure, C = C, C = O group ratio, specific surface area, and pore size of the synthesized sample were analyzed by a series of characterizations. The main active species of the Co3O4/CB-50/PMS system were demonstrated to be SO4•−, O2•−, and 1O2, and the possible pathway of CIP degradation was proposed. Besides, the microwave-assisted solid strategy is universal for synthesis of composites using different carbon materials. This study offers a unique method to synthesize high-performance, environment-friendly, and low-cost catalysts for PMS activation toward antibiotic degradations.