High 1T phase and sulfur vacancies in C-MoS2@Fe induced by ascorbic acid for synergistically enhanced contaminants degradation

Abstract

Applicating co-catalyst into Fenton-like advanced oxidation processes to improve the performance for wastewater remediation has attracted widespread attention. Among them, developing highly active and green heterogeneous catalyst integrating homogeneous ferrous ions and inorganic co-catalyst is a great challenge. Herein, ascorbic acid additive was creatively introduced into the precursor composed of thiourea, sodium molybdate and ferric chloride to synthesize carbon intercalated molybdenum disulfide anchoring iron (C-MoS2@Fe) by a simple one-step hydrothermal method. C-MoS2@Fe exhibited an amazing apparent first-order constant as high as 0.739 min−1 about 10 times higher than that of the homogeneous Fe2+/MoS2 system for the sulfamethoxazole (SMX) removal and achieved 68.7% removal of TOC in 6 min, which was attribute to the synergistic enhancement of high 1T phase (82.0%) and sulfur vacancies induced by the introduction of ascorbic acid. Notably, the C-MoS2@Fe was also capable of efficiently degrading multiple organic contaminants such as pharmaceuticals, phenolic compounds, and organic dyes. Compared with the homogeneous Fe2+/PMS system, the C-MoS2@Fe/PMS system expanded the effective pH range (2.0 ∼ 9.0) and the ultralow iron ions leaching (0.204 mg L-1) avoided the formation of iron containing sludge. The results of electron paramagnetic resonance (EPR), radical quenching and probe experiments indicated that •OH was the main active species with the contribution rate about 60.3%. Furthermore, possible degradation pathways were proposed based on the intermediate products of SMX investigated by LC-MS. This study provides novel insights for the development of highly active and green catalysts for wastewater remediation.