Qin Weihua, Ma Yueming, He Ting, Hu Jingbin, Gao Pan, Yang Shaoxia
School of Water Resources and Hydropower Engineering, North China Electric Power University, Beijing 102206, China.
National Engineering Laboratory for Biomass Power Generation Equipment, School of Renewable Energy, North China Electric Power University, Beijing 102206, China.
Nanomaterials (Basel). 2022 Nov 23;12(23):4138. doi: 10.3390/nano12234138.
A heterogeneous Fenton-like catalyst with single redox site has a rate-limiting step in oxidant activation, which limited its application in wastewater purification. To overcome this, a bimetallic doping strategy was designed to prepare a heterogeneous Fenton-like catalyst (Fe-Mo/rGO) with a double-reaction center. Combined with electrochemical impedance spectroscopy and density functional theory calculation, it was confirmed that the formation of an electron-rich Mo center and an electron-deficient Fe center through the constructed Fe-O-Mo and Mo-S-C bonding bridges induced a higher electron transfer capability in the Fe-Mo/rGO catalyst. The designed Fe-Mo/rGO catalyst exhibited excellent sulfamethazine (SMT) degradation efficiency in a broad pH range (4.8-8.4). The catalytic performance was hardly affected by inorganic anions (Cl, SO and HCO) in the complicated and variable water environment. Compared to Fe/rGO and Mo/rGO catalysts, the SMT degradation efficiency increased by about 14.6 and 1.6 times in heterogeneous Fenton-like reaction over Fe-Mo/rGO catalyst. The electron spin resonance and radical scavenger experiments proved that ·O/HO· and O dominate the SMT removal in the Fe-Mo/rGO/HO system. Fe and Mo, as active centers co-supported on rGO, significantly enhanced the electron transfer between catalyst, oxidant, and pollutants, which accelerated the reactive oxygen species generation and effectively improved the SMT degradation. Our findings offer a novel perspective to enhance the performance of heterogeneous Fenton-like catalysts by accelerating the electron transfer rate in the degradation of organic pollutants.
具有单一氧化还原位点的非均相类芬顿催化剂在氧化剂活化过程中存在速率限制步骤，这限制了其在废水净化中的应用。为克服这一问题，设计了一种双金属掺杂策略来制备具有双反应中心的非均相类芬顿催化剂（Fe-Mo/rGO）。结合电化学阻抗谱和密度泛函理论计算，证实通过构建的Fe-O-Mo和Mo-S-C键桥形成富电子的Mo中心和缺电子的Fe中心，在Fe-Mo/rGO催化剂中诱导了更高的电子转移能力。所设计的Fe-Mo/rGO催化剂在较宽的pH范围（4.8-8.4）内表现出优异的磺胺二甲嘧啶（SMT）降解效率。在复杂多变的水环境中，催化性能几乎不受无机阴离子（Cl、SO和HCO）的影响。与Fe/rGO和Mo/rGO催化剂相比，在非均相类芬顿反应中，Fe-Mo/rGO催化剂对SMT的降解效率提高了约14.6倍和1.6倍。电子自旋共振和自由基清除剂实验证明，·O/HO·和O主导了Fe-Mo/rGO/H2O2体系中SMT的去除。负载在rGO上的Fe和Mo作为活性中心，显著增强了催化剂、氧化剂和污染物之间的电子转移能力，加速了活性氧的生成，有效提高了SMT的降解效果。我们的研究结果为通过加速有机污染物降解过程中的电子转移速率来提高非均相类芬顿催化剂性能提供了新的视角。
