Fe0@Fe3O4 nanoparticles with dispersibility and stability better than single nano zero-valent iron (nZVI) were synthesized and combined with hydrogen peroxide to constitute a heterogeneous Fenton-like system, which was creatively applied in the degradation of 2,4-dichlorophenoxyacetic acid (2,4-D). The effects of different reaction conditions like pH, hydrogen peroxide concentration, temperature, and catalyst dosage on the removal of 2,4-D were evaluated. The target pollutant was completely removed in 90min; nearly 66% of them could be mineralized, and the main intermediate product was 2,4-dichlorophenol. Synergistic effects between nZVI and Fe3O4 made the 2,4-D degradation efficiency in the Fe0@Fe3O4/H2O2 system greater than in either of them alone. More than a supporter, Fe3O4 could facilitate the degradation process by releasing ferrous and ferric ions from the inner structure. The reduction of 2,4-D was mainly attributed to hydroxyl radicals including surface-bound ∙OH and free ∙OH in solution and was dominated by the former. The possible mechanism of this Fe0@Fe3O4 activated Fenton-like system was proposed.

中文翻译：

---

磁铁矿纳米颗粒上纳米级零价铁对2,4-二氯苯氧乙酸的多相类芬顿催化降解

合成了分散性和稳定性优于单一纳米零价铁（nZVI）的Fe0@Fe3O4纳米颗粒，并与过氧化氢结合构成异质类芬顿体系，创造性地应用于2,4-二氯苯氧乙酸的降解。 2,4-D)。评估了不同反应条件（如 pH 值、过氧化氢浓度、温度和催化剂用量）对 2,4-D 去除的影响。90min内完全去除目标污染物；其中近66%可矿化，主要中间产物为2,4-二氯苯酚。nZVI 和 Fe3O4 之间的协同效应使 Fe0@Fe3O4/H2O2 系统中的 2,4-D 降解效率高于单独使用它们中的任何一个。不仅仅是支持者，Fe3O4 可以通过从内部结构释放亚铁和三价铁离子来促进降解过程。2,4-D 的还原主要归因于羟基自由基，包括表面结合的 ∙OH 和溶液中的游离 ∙OH，且以前者为主。提出了这种 Fe0@Fe3O4 激活类芬顿体系的可能机制。