Enhanced decomposition of H2O2 by molybdenum disulfide in a Fenton-like process for abatement of organic micropollutants

Accelerating the rate-limiting step of Fe 3+ /Fe 2+ conversion is a major challenge for H 2 O 2 decomposition in conventional Fenton process. In this study, the catalytic mechanism of H 2 O 2 by molybdenum disulfide (MoS 2 ) nanoparticles and Fe 3+ ions was revealed and the abatement of organic micropollutants was investigated. The presence of both MoS 2 and Fe 3+ can efficiently decompose H 2 O 2 . Reaction system of H 2 O 2 /MoS 2 /Fe 3+ is found to remove most of the tested pollutants by over 80% (except 65.9% for carbamazepine) within 60 min at pH of 3.0. Effective pH range of this reaction system can be extended to pH of 5.0. Adding MoS 2 to Fe 3+ /H 2 O 2 system promotes the Fe 3+ /Fe 2+ cycle and improves the reaction rate between Fe 3+ and H 2 O 2 . The formation of Mo 6+ ions and Mo 6+ peroxo-complexes is beneficial to H 2 O 2 decomposition and pollutant degradation . Electron paramagnetic resonance (EPR) measurements and quenching experiments confirm the important role of hydroxyl radicals in H 2 O 2 /MoS 2 /Fe 3+ system. Chloride ions (Cl − ) promote degradation, while bicarbonate ions (HCO 3 − ) inhibit degradation. As H 2 O 2 concentration increases from nil to 1.0 mM, the value of total EE/O decreases from 0.083 to 0.003 kWh L −1 , and the most energy efficient condition is determined. This study provides a new pathway for efficient decomposition of H 2 O 2 by Fe 3+ ions in an extended pH range, which is considered a facile and promising strategy for wastewater treatment .