Efficient pH-universal degradation of antibiotic tetracycline via CoP decorated Neosinocalamus affinis biochar.

Considering the complexity of traditional cobalt phosphide (CoP) loaded biochar synthesis research on a simple and efficient synthesis method has practical significance. In this study, after phosphoric acid activation, Neosinocalamus affinis biochar (NAB) and nanoplate CoO quickly formed a CoP-NAB composite material with high CoP crystallinity and was uniformly dispersed on the surface of NAB in a microwave reactor. CoP-NAB has an excellent catalytic degradation effect in the activation of peroxymonosulfate (PMS) to degrade tetracycline (TC). The optimal TC degradation efficiency was achieved with the addition of 50 mg L TC concentration, 0.2 g L catalysts, 0.406 mM PMS and pH = 6.02. In addition, according to the pseudo-first-order reaction rate constant calculation, the composite of CoP-NAB and PMS the synergy efficiency is 81.55 %. Compared with CoP-NAB (10.83 %) and PMS (7.62 %) alone, the CoP-NAB/PMS system has a significant promotion effect on the degradation of TC molecules. Additionally, the CoP-NAB/PMS system had a TC mineralization rate of 68 % in 30 min. Furthermore, after a series of characterization, detection and analysis, and influencing factor experiments, we proposed a potential mechanism for the CoP-NAB/PMS reaction system to degrade TC and found that singlet oxygen (O) plays an essential role in the non-radical degradation process. Finally, according to the liquid chromatography-mass spectrometry (LC-MS) detection of TC degradation intermediates, a possible degradation route was proposed. Therefore, this work uses microwave technology to present a novel and simple synthesis method for transition metal phosphides, which provides potential application value for the treatment of actual wastewater with heterogeneous catalysts.