Boosting H2O2 activation by Cu and Ce co-doped g-C3N4 for pollutants removal: From the free radical pathway to the non-free radical pathway

Abstract

Recently, materials synthesized by combining graphitic carbon nitride (g-C3N4) and metallic material have caught a lot of attention because of their high catalytic activity. In this paper, a novel g-C3N4 catalyst doped with Cu and Ce (labeled as CuCe-CN) is presented. CuCe-CN can effectively activate H2O2 to degrade tetracycline hydrochloride (TC-HCl) and cause TC-HCl to be completely degraded within one hour. The presence of CeO2 in catalyst provides the redox electron pairs of Ce(IV) and Ce(Ⅲ), and also facilitates the generation of 1O2 during the experimental process. By comparing the main active substances of CuCe-CN and Cu-CN, the fact that the doping of Ce changes the degradation pathway from free radical pathway to non-free radical pathway can be found. It can be demonstrated by electrochemical tests that the doping of Ce promotes the electron transfer in CuCe-CN, which can benefit the generation of reactive oxidation species (ROS), especially 1O2. CuCe-CN/H2O2 system has a good adaptability to the changes of environment. The catalytic performance of CuCe-CN does not be negatively affected by inorganic salt ions, and maintains high activity in natural aqueous environments. In this research, a new method for optimizing the activation behavior of g-C3N4 and a new non-free radical degradation method of TC-HCl were provided.