Mechanistic Inference On Peroxymonosulfate Activation For Bisphenol A Removal By CoP/C And Graphene

The research on advanced oxidation processes（AOPs）based on the catalytic activation of peroxymonosulfate（PMS）is carried out in this paper,aiming at the technical challenges that recalcitrant organic pollutant（bisphenol A）are difficult to treat in water bodies.In view of the good stability and environmental protection of carbon materials and the high catalytic efficiency of transition metals,graphene with high specific surface area and new hybrid Co P/C hollow nanospheres were prepared.The effects of different experimental parameters on its activation of PMS were studied,and a variety of detection methods were used to in-depth explore the mechanism of bisphenol A（BPA）degradation by using different catalysts to activate PMS.The main contents are as follows:1.Traditional methods limit the amount of interface active sites and electron transfer efficiency in supported catalysts,which makes the practical catalysis performance of heterogeneous catalysts for advanced oxidation processes not really perfect.In this work,novel Co P/C hollow hybrids with abundant active interfaces and high surface electron transfer were successfully synthesized.The carbon matrix and Co P combined uniformly and formed a stable conductive network throughout structure.The unique structure of Co P/C endowed them with high catalysis efficiency,as well as low environmental harm in actual BPA degradation.BPA(36 mg L^-1)removal rate could reach to 100%within 8 min and the leaching of cobalt ions was far lower than the wastewater discharge standard.The efficiency of BPA degradation was positively correlated with the dosages of Co P/C and PMS.The Co P/C/PMS/BPA system also showed the impressive degradation performance at a wide pH range（pH=3～11）and even in practical applications,exhibiting outstanding stability and reusability.Furthermore,through radical quenching experiments,electron paramagnetic resonance（EPR）test and electrochemical analysis,an exhaustive research was conducted to elucidate the PMS activation mechanism by Co P/C.LCMS-IT-TOF was used to detect the intermediates during BPA degradation.2.In this work,we intensively studied the mechanism which graphene with different surface functions activated PMS to remove BPA.The multiple detection methods were used to characterize the different graphene samples,and the effects of their PMS activation on the BPA degradation was contrasted.The effect of different experimental parameters on the degradation of BPA was also explored.Specially,different from traditional methods of preparing graphene,the thermally reduced graphene（TRG） in this study has a larger specific surface area and a strong adsorption capacity for BPA.The combination of adsorption and degradation makes the removal efficiency of BPA further improved.0.10 g L^-1 G1000 can completely almost degrade BPA(19 mg L^-1)within 15 min.Through free radical quenching experiment,electron paramagnetic resonance（EPR）test and electrochemical analysis,an exhaustive research was carried out to clarify the activation mechanism of PMS by graphene with different surface structures.