Effect of MoS2 on phenol decomposition in water after high-voltage pulse discharge treatment

Abstract

Molybdenum disulfide (MoS₂) was added to the system after being treated with high-voltage pulse discharge plasma to improve the degradation efficiency of pollutants and reduce energy consumption. The discharge plasma-treated solution contains hydrogen peroxide and metal iron ions, and MoS₂ addition can cause co-catalytic Fenton reaction. The effects of discharge time, initial pH, phenol concentration, MoS₂ dosage, discharge voltage, and gas type on phenol removal and aqueous H₂O₂ concentration were mainly investigated. Results showed that the addition of MoS₂ after plasma treatment can reduce the plasma treatment time by 70% and maintain or even increase the degradation efficiency of phenol from 40% (after 20 min of discharge plasma) to 92% (after turning off the discharge and dosing with MoS₂ for 30 min). Acidic conditions (pH = 3-4) and oxygen were beneficial to phenol removal. MoS₂ addition greatly improved the catalytic oxidation of discharge plasma. This study provides a promising direction for water treatment based on plasma technology.

Keywords: Catalytic reaction; High-voltage pulse plasma; Molybdenum disulfide; Phenol wastewater.