Synthesis of Mo and Fe Co-Doped G-C3n4 Composite 8-Cnmf12 Assisted by Soluble Alcohol-Glycol Activated Pms for Phenol Degradation: Co-Degradation Mechanism of Free Radicals and Non-Free Radicals

Abstract

The advanced oxidation technology based on peroxymonosulfate is an efficient and feasible method for the treatment of phenol wastewater. Therefore, bimetal supported graphite phase carbon nitride in the activation process of PMS has become a research focus in recent years. In this study, graphite phase carbon nitride was doped with Mo and Fe bimetal, and soluble organic alcohol was used: Methanol, ethanol and ethylene glycol assisted liquid phase deposition calcination method successfully prepared composite catalyst materials, in which ethylene glycol as an auxiliary agent, 8-CNMF12 prepared after deposition calcination is the best, forming a bimetallic active site in the catalyst structure. The metal valence Mo6+/Mo4+ and Fe3+/Fe2+ promoted the activation of PMS to degrade phenol effectively through REDOX double cycle. When PH is neutral, the degradation rate of 20 mg/L phenolsolution with catalyst 8-CNMF12 added 0.35 g/L, PMS added 0.6 mM, reached 90% in 10 min and 95% in 40 min. In the pH range of 3-11 and different anions, the degradation rate of 8-CNMF12 / PMS catalytic system can reach about 95% within 40 min. At the same time, the degradation effects of RhB, MB and OFX for different pollutants were 99%, 100% and 81%, respectively, within 10 min. After five cycles of reaction, the efficiency of activated PMS for phenol degradation remained at 85%, showing good REDOX ability. EPR and quenching experiments show that in 8-CNMF12/PMS system, the degradation mechanism is dominated by free radicals and non-free radicals, and the main active species are: ･SO4-, ･OH-, ･O2- and 1O2, and less high-valent metal-oxo species Fe IV = O. This study provides a new idea for the study of bimetal supported graphite phase carbon nitride and the theoretical study of degradation mechanism.

Keywords: aops, Mo、Fe co-doped g C3N4, Activating PMS, Phenol degradation