Enhancing the yield of H2O2 and bisphenol A degradation via a synergistic effect of photoelectric co-catalysis by using NPC/C3N4 electrode

Abstract

This study reported a photoelectric co-catalyst system of jet-flow reactor for efficient mineralization of Bisphenol A (BPA), where H2O2 was photoelectro-generated in situ from O2 reduction on gas diffusion electrodes fabricated by nitrogen-doped porous carbon and graphitic carbon nitride (NPC/g-C3N4). Current density, aeration rate, amount of MoS2 and FeSO4 catalyst in the jet-flow reactor photoelectrocatalysis system for BPA removal were investigated. The NPC/g-C3N4 cathodes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron spin resonance (ESR), and the electrochemical workstation. The results show that at pH 7, the NPC/g–C3N4–(60%) has the highest rate of electrical generation hydrogen peroxide. When the pH rised, at pH values of 7, the cumulative of hydrogen peroxide increased, when the solution get slight alkaline, it was gradually decreased. Compared with the traditional electro-Fenton technology, the photoelectric method of co-catalysis has strong ·OH production rate and high oxidation ability. A possible mechanism for BPA degradation was oxidized by hydroxyl radical (·OH), resulting in the formation of shorter chain bisphenol A (BPA), which followed the same reaction cycle as BPA until it was mineralized. The removal rate of BPA can reach 100% within 20 min, the TOC removal rate up to 90%. This work provides new opinion into the development of a photoelectric collaborative system for H2O2 generation and the fast BPA degradation.