The sluggish regeneration rate of Fe^II and low operating pH still restrict the wider application of classical Fenton process (Fe^II/H₂O₂) for practical water treatment. To overcome these challenges, we exploit the Mn–CNH co-catalyst to construct a solid–liquid interfacial Fenton reaction and accelerate the Fe^III/Fe^II redox cycle at the interface for sustainably generating ^•OH from H₂O₂ activation. The Mn–CNH co-catalyst exhibits an excellent regeneration rate of Fe^II (∼65%) and a high tetracycline removal rate (K_obs) of 0.0541 min^–1, which is 19.0 times higher than that of the Fe^II/H₂O₂ system (0.0027 min^–1) at a near-neutral pH (pH ≈ 5.8), and it also attains 100% degradation of sulfamethoxazole, rhodamine B, and methyl orange. The cyclic mechanism of Fe^III/Fe^II is further elucidated in an atomic scale by combining characterizations and density functional theory calculations, including Fe_aq^III specific adsorption and the electron-transfer process. Mn active sites can accumulate electrons from the matrix and adsorb Fe_aq^III to form Mn–Fe bonds at the solid–liquid interface, which accelerate electron transfer from Mn–CNH to Fe_aq^III and promote the regeneration of Fe^II at a wide pH range with a lower energy barrier. The regeneration rate of Fe^II in the Mn–CNH/Fe^II/H₂O₂ system outperforms the benchmark Fenton system and other typical metal nanomaterials, which has great potential to be widely applied in actual environment remediation.

中文翻译：

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在接近中性 pH 值的 Mn-CNH 助催化剂上，在有效的固-液-界面芬顿反应中加速 FeIII-Aqua 络合物的还原

Fe ^II缓慢的再生率和较低的操作 pH 值仍然限制了经典 Fenton 工艺（Fe ^II /H ₂ O ₂）在实际水处理中的广泛应用。为了克服这些挑战，我们利用 Mn-CNH 助催化剂构建固-液界面芬顿反应并加速界面处的 Fe ^III /Fe ^II氧化还原循环，从而可持续地从 H ₂ O ₂活化中生成^• OH 。Mn-CNH 助催化剂表现出优异的 Fe ^II再生率(~65%) 和0.0541 分钟的高四环素去除率 ( K _obs )^–1，在接近中性的 pH 值（pH ≈ 5.8）下比 Fe ^II /H ₂ O ₂系统（0.0027 min ^–1）高 19.0 倍，并且它还实现了磺胺甲恶唑、罗丹明 B 的 100% 降解，和甲基橙。通过结合表征和密度泛函理论计算，包括 Fe _aq ^III特异性吸附和电子转移过程，在原子尺度上进一步阐明了 Fe ^III / Fe ^II的循环机制。Mn 活性位点可以从基体中积累电子并吸附 Fe _aq ^III在固-液界面形成 Mn-Fe 键，加速电子从 Mn-CNH 转移到 Fe _aq ^III并促进 Fe ^II在较宽的 pH 范围内以较低的能垒再生。Fe ^II在Mn-CNH/Fe ^II /H ₂ O ₂体系中的再生率优于基准Fenton体系和其他典型的金属纳米材料，在实际环境修复中具有广泛应用的潜力。