Catalytic degradation of bisphenol A by heterogeneous bimetal composite carbon in the PMS and H2O2 systems: Performance and mechanism

Abstract

Bisphenol A (BPA) has caused adverse effects on human health and natural environment as a poisonous endocrine disrupting chemical. In this study, the bimetal composite carbon material (Co&Ni/C) with carbon nanotubes was fabricated for BPA degradation by the catalytic pyrolysis method. The dense carbon nanotubes were observed on the carbon surface with a specific surface area of up to 265.68 m2/g. The cobalt oxide and nickel oxide were distributed evenly causing more catalytic sites. The factors affecting catalytic efficiency for degrading BPA by the peroxymonosulfate (PMS) and hydrogen peroxide (H2O2) systems were investigated and compared systematically. The Co&Ni/C showed better catalytic performance with a BPA degradation rate of nearly 80%–100% in the Co&Ni/C-PMS process. However, BPA was difficult to be removed completely by H2O2 with a mineralization efficiency below 40% under most reaction conditions. The different degradation pathways and mechanisms under the oxidation of SO4•− and HO• were also discussed respectively, and the intermediate reactions included radical adduct formation, hydroxylation, skeleton oxidation rearrangement, dehydration and ring cleavage. It was proved that the stable Co&Ni/C possessed good reusability for remaining 77% removal rate of BPA after a 4-stage adsorption-degradation reaction. This paper revealed that the synthetic Co&Ni/C was hopeful as the adsorption material with efficient catalytic activity to provide new insight into BPA in-situ degradation.