Hu Yi, Zhou Yao, Ding Rongjian, Ye Xinchun, Chu Chu, Liu Ling-Ling, Tian Lei, Jiang Xunheng, Zhang Long-Shuai, Zou Jian-Ping, Luo Shenglian
Key Laboratory of Jiangxi Province for Persistent Pollutants Prevention Control and Resource Reuse, Nanchang Hangkong University, Nanchang 330063, P. R. China.
School of Materials Science and Engineering, Beihang University, Beijing 100191, P. R. China.
Environ Sci Technol. 2025 Aug 12;59(31):16812-16821. doi: 10.1021/acs.est.5c07284. Epub 2025 Aug 1.
Single-atom catalysts (SACs) show excellent activity and selectivity in Fenton-like reactions due to the atomically dispersed and homogeneous active sites. However, the sluggish redox kinetics of single-atom sites cause poor stability and durability. Herein, a graphitic carbon nitride-supported Fe and Cu dual-site catalyst with N-Fe-Cu-N configuration (FeCu-CN) was designed and prepared, which promotes HO activity through a sustainable dual-metal redox cycle and shows excellent pollutant degradation performance. The optimized FeCu-CN efficiently activates HO to degrade sulfamethoxazole, with 23 and 4 times higher rates than Fe-CN and Cu-CN, respectively. Experimental and density functional theory (DFT) calculations indicate that the Cu site of FeCu-CN optimizes the electronic structure of Fe site and provides electrons to facilitate the Fe(III)/Fe(II) cycle. The reduction of Cu(II) by HO and •O could promote the Cu(II)/Cu(I) cycle, maintaining the catalytic activation stability of FeCu-CN. Moreover, the synergistic effect of Fe and Cu sites in FeCu-CN promotes the adsorption of HO and reduces the dissociation energy barrier of HO. The FeCu/HO system exhibits strong resilience to changes in pH (from 3.18 to 9.35) and the coexisting substances. In continuous flow experiments, it also shows a long-term degradation effect on water pollutants. The FeCu-CN/HO system has excellent anti-interference ability and application potential. This study develops a strategy for a persistent dual-metal synergistic redox cycle, providing new mechanistic insights for designing Fenton-like catalysts in efficient and environmentally friendly wastewater treatment.
单原子催化剂（SACs）由于其原子分散且均匀的活性位点，在类芬顿反应中表现出优异的活性和选择性。然而，单原子位点缓慢的氧化还原动力学导致其稳定性和耐久性较差。在此，设计并制备了一种具有N-Fe-Cu-N构型的石墨相氮化碳负载的Fe和Cu双位点催化剂（FeCu-CN），其通过可持续的双金属氧化还原循环促进羟基自由基（•OH）活性，并表现出优异的污染物降解性能。优化后的FeCu-CN能有效激活•OH以降解磺胺甲恶唑，其降解速率分别比Fe-CN和Cu-CN高23倍和4倍。实验和密度泛函理论（DFT）计算表明，FeCu-CN的Cu位点优化了Fe位点的电子结构，并提供电子以促进Fe(III)/Fe(II)循环。•OH和超氧阴离子（•O）对Cu(II)的还原可促进Cu(II)/Cu(I)循环，维持FeCu-CN的催化活化稳定性。此外，FeCu-CN中Fe和Cu位点的协同效应促进了•OH的吸附，并降低了•OH的解离能垒。FeCu/•OH体系对pH值变化（从3.18至9.35）和共存物质具有很强的耐受性。在连续流实验中，它对水中污染物也表现出长期降解效果。FeCu-CN/•OH体系具有优异的抗干扰能力和应用潜力。本研究开发了一种持续双金属协同氧化还原循环的策略，为设计高效环保的废水处理类芬顿催化剂提供了新的机理见解。
