Electrochemical oxidation of bisphenol A with a Fe-N-C/persulfate three-dimensional electrochemical system

In this study, an effective three-dimensional (3D) electrochemical system based on persulfate was developed, utilizing Fe-N-C compostie as the particle electrodes, and its electrocatalytic performance for the oxidation of bisphenol A was evaluated. With the synergetic effect of Fe-N-C catalyst and electric current, peroxydisulfate is activated to generate highly oxidative sulfate radicals (SO4 center dot-) and hydroxyl radicals ((OH)-O-center dot), and the (OH)-O-center dot playing a leading role in the oxidation of BPA. In this process, the redox cycle of Fe2+/Fe3+ acts as the main catalytic active center to produce SO4 center dot-, (OH)-O-center dot and O-2(center dot-), while pyridine N and graphite carbon cooperate to catalyze the formation of O-1(2) and promote direct electron transfer, with their reduction by 37.19% and 3.34%, respectively, highlighting their crucial role in these processes. During the degradation of bisphenol A, coupling polymerization occurred at the same time, which may be due to the stabilization and instantaneous resonance of the intermediate on the surface of the catalyst caused by direct electron transfer, which induced the polymerization of oxide intermediate. O-1(2) not only oxidizes BPA into low molecular weight products, but also extracts hydrogen atoms to form phenoxy free radicals. The coupling of these free radicals promotes the formation of macromolecular polymers and separation from water. This parallel treatment mechanism of degradation and polymerization effectively reduces the emission of CO2 and the mineralization of organic matter. Based on the above findings, the E/PDS/Fe-N-C system has broad potential in the treatment of environmental pollutants.