Fenton reaction is extensively used in wastewater treatment to produce ^•OH, which can be used to remove organic pollutants excellently. However, the greatest issue of the process is the low efficiency of Fe²⁺/Fe³⁺ conversion cycle and hydrogen peroxide (H₂O₂) decomposition rate (<30%). In this study, molybdenum disulfide (MoS₂) was used as a co-catalyst in Fenton system to accelerate the oxidation of acid orange 7 (AO7) dye. The enhanced removal efficiency was attributed to that the unsaturated S atoms on the surface of MoS₂ could capture the protons in solutions and turn into H₂S, exposing the active sites with reducibility and accelerating the conversion of Fe²⁺/Fe³⁺. A high degradation rate of 98% was obtained in 30 min under the optimal conditions of AO7 concentration 100 mg/L, MoS₂ 6 g/L, FeSO₄·7H₂O 50 mg/L, H₂O₂ concentration 1.5 mmol/L, and pH 3.5. Furthermore, the degradation pathway and mechanism of AO7 were thoroughly discussed. The toxicity of the intermediates during the degradation progress slightly increased initially, which then decreased to nontoxicity. MoS₂ can keep stable, which can maintain high AO7 removal efficiency even after being reused for seven times. Moreover, the obtained results provide a theoretical basis and guidance for the application of inorganic co-catalyst in practical wastewater remediation applications.

中文翻译：

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二硫化钼对 Fenton 反应降解酸性橙 7 染料的共催化作用：反应机理、性能优化和毒性评价

芬顿反应广泛用于废水处理，产生^• OH，可以很好地去除有机污染物。然而，该工艺的最大问题是Fe ²⁺ /Fe ³⁺转化循环效率低和过氧化氢（H ₂ O ₂）分解率（<30%）。在这项研究中，二硫化钼（MoS ₂）被用作芬顿体系中的助催化剂，以加速酸性橙7（AO7）染料的氧化。去除效率的提高归因于 MoS ₂表面的不饱和 S 原子可以捕获溶液中的质子并转化为 H ₂S，以还原性暴露活性位点并加速Fe ²⁺ /Fe ³⁺的转化。在AO7浓度100 mg/L、MoS ₂ 6 g/L、FeSO ₄ ·7H ₂ O 50 mg/L、H ₂ O ₂浓度1.5 mmol/ L的最佳条件下，30 min内降解率高达98%。L，pH 3.5。此外，还深入讨论了AO7的降解途径和机制。降解过程中中间体的毒性最初略有增加，然后降低至无毒。硫化钼₂保持稳定，重复使用七次后仍能保持较高的AO7去除效率。此外，所得结果为无机助催化剂在实际废水修复应用中的应用提供了理论依据和指导。