Effect of the presence of inorganic anions on the degradation of phenol by dielectric barrier discharge plasma combined with RGO-TiO2. (June 2021) - Sang, Wenjiao
Graphical abstract: Highlights: DBD plasma coupled RGO-TiO2 composites was used to degrade phenol. RGO-TiO2 composites were prepared successfully and characterized. Initial reaction conditions were optimized from the perspective of energy yield. The effect of inorganic anions on the DBD-RGO-TiO2 system was studied. The degradation mechanism and pathways of phenol were proposed by HR-LC–MS. Abstract: In this study, RGO-TiO2 composites was combined with dielectric barrier discharge plasma for phenol degradation, and the effects of initial reaction conditions and some concomitant inorganic anions (Cl −, CO3 2−, SO4 2− and NO3 − ) on the removal efficiency of phenol were investigated. RGO-TiO2 composite materials were prepared by sol-gel method and characterized by XRD, SEM, FTIR and PL firstly. The experimental results showed that when the input voltage was 90 V and the catalyst dosage was 1.5 g/L, the removal efficiency of 1.06 mM phenol reached 94.7 % after 20 min during reaction. The presence of Cl − and SO4 2− had a significant inhibitory effect on the degradation of phenol at low concentration, while the inhibitory effect of NO3 − could be ignored. Surprisingly, after 10 mM CO3 2− added, the synergetic system completely degraded the phenol solution within 16 min. The radical quenching experiments was carried out, and the variation of O3 and H2 O2 during the degradation of phenol were detected. Finally, the intermediate products of phenol degradation were analyzed by HR-LC–MS, and the possible degradation path of phenol was proposed.