The cycling rate of iron ions has been reported to limit the Fenton reaction rate. It is, therefore, vital to enhance the cycling rate of iron ions. A composite three-dimensional electrode (FOC) was synthesized using glucose, ammonium carbonate, and FeCl3 through a combination of hydrothermal synthesis and calcination. The electrode’s conditions were subsequently optimized for the applicable pH range and the concentration of methylene blue (MB) that could be effectively degraded. At an FOC-800 dosage of 0.5 g/L, a supply voltage of 4 V, and an initial pH of 4, a degradation rate of 98 % for 10 mg/L MB was achieved, with a 67.5 % reduction in total organic carbon using 2 g/L Na2S2O3 as the electrolyte. The material also demonstrated efficacy in degrading both chemical and pharmaceutical wastewater. A comparative analysis using Na2SO4 as the electrolyte confirmed that Na2S2O3 effectively promoted the cycling of iron ions, enhancing the degradation performance of FOC and expanding its effective pH range. High-performance liquid chromatography (HPLC) was employed to monitor the concentration changes of S2O32- and SO42- during the reaction, while LC-MS was used to identify the degradation products of MB, and ECOSAR was utilized to assess the toxicity of these products. Burst experiments and EPR analysis identified ●OH as the primary active species responsible for degradation, with O2∙- playing a supporting but not dominant role.

中文翻译：

---

Fe（II.）/Fe（III.） 循环增强了以 Fe3O4@C 为三维电极的亚甲蓝的电 Fenton 降解


据报道，铁离子的循环速率限制了 Fenton 反应速率。因此，提高铁离子的循环速率至关重要。以葡萄糖、碳酸铵和 FeCl3 为原料，通过水热合成和煅烧相结合，合成了复合三维电极 （FOC）。随后，针对适用的 pH 范围和可有效降解的亚甲基蓝 （MB） 浓度优化了电极的条件。当 FOC-800 剂量为 0.5 g/L、电源电压为 4 V、初始 pH 值为 4 时，使用 2 g/L Na2S2O3 作为电解质，10 mg/L MB 的降解率为 98%，总有机碳减少了 67.5%。该材料还显示出降解化学和制药废水的功效。以 Na2SO4 为电解质的比较分析证实，Na2S2O3 有效促进了铁离子的循环，增强了 FOC 的降解性能并扩大了其有效 pH 范围。采用高效液相色谱 （HPLC） 监测反应过程中 S2O32- 和 SO42- 的浓度变化，同时使用 LC-MS 鉴定 MB 的降解产物，使用 ECOSAR 评估这些产物的毒性。爆发实验和 EPR 分析确定 ●OH 是导致降解的主要活性物质，其中 O2∙- 起支持作用但不是主导作用。