F-enhanced anti-bonding activation effect of FeO on catalytic degradation of chloramphenicol by dielectric barrier discharge plasma

In this study, dielectric barrier discharge (DBD) plasma and F/FeO catalyst were utilized to degrade chloramphenicol (CAP) in water. The operation conditions, catalyst properties and catalytic mechanisms were systematically studied, and the anti-bonding activation effect was highlighted as the key for the catalytic effect. The results show that CAP was 100% degraded by DBD and F/FeO after 8 min treatment under optimal operating conditions, and F/FeO catalyst increased the degradation efficiency of CAP by 34.1%. FeO transferred electrons into the & pi;* anti-bonding orbital of O3 and the & sigma;* anti-bonding orbitals of H2O2 and O2, leading to an anti-bonding activation effect and weakening their bonding. Additionally, F facilitated the electron transfer of FeO and changed the stable adsorption of O3 and H2O2 on FeO to dissociated adsorption on F/FeO. The -OH groups generated by the H2O2 dissociation could induce a non-Fenton catalytic pathway. The intensive electron transfer of F/FeO converted O2 into & BULL;O2  . The ant-bonding activation of O3, H2O2 and O2 on F/FeO facilitated the production of & BULL;OH. A degradation pathway for CAP was proposed based on the findings of experiments and simulation. The developmental toxicity of CAP was weakened after F/FeO/DBD treatment. This study proposes an efficient plasma catalyst for purifying antibiotic wastewater, and provides a new insight into the mechanism of the plasma/catalysis process.