National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing, 100124, PR China.
Chemosphere. 2022 Jun;296:134072. doi: 10.1016/j.chemosphere.2022.134072. Epub 2022 Feb 22.
In this paper, a CuCo-O@CNTs/NF electrode was successfully prepared and used for in-situ degradation of sulfamethoxazole (SMX) in an electro-Fenton-like system. Carbon nanotubes (CNTs) and coral-like copper-cobalt oxides were successively loaded on nickel foam (NF). CNTs contributed to improving the dispersibility and stability of copper-cobalt oxides, and the coral-like copper-cobalt oxide catalyst was anchored on CNTs without any adhesive. In the electro-Fenton-like system, dissolved oxygen can be reduced to superoxide anions in a one-electron step, which could be further transformed into hydrogen peroxide and then reacted with the active components on the electrode to generate reactive oxygen species (ROS) to participate in the degradation of SMX. Almost 100% SMX removal was obtained within 60 min in a wide near-neutral pH range (5.6-9.0), and the electrode could still achieve a 90.4% removal rate after ten recycle runs. Radical-quenching results showed that superoxide anions were the main species in the degradation of SMX. In addition, a possible degradation pathway of SMX was proposed. According to the result of toxicological simulations, the toxicity of the pollutant solution during the degradation process exhibited a decreasing trend. This study provides new insights for in-situ catalysis of electrodes with bimetallic active components to generate ROS for high-efficiency degradation of refractory organic pollutants.
本文成功制备了 CuCo-O@CNTs/NF 电极，并将其用于电芬顿类似体系中磺胺甲恶唑（SMX）的原位降解。碳纳米管（CNTs）和珊瑚状铜钴氧化物依次负载在泡沫镍（NF）上。CNTs 有助于提高铜钴氧化物的分散性和稳定性，而珊瑚状铜钴氧化物催化剂则无需任何粘合剂即可锚定在 CNTs 上。在电芬顿类似体系中，溶解氧可以在单电子步骤中还原为超氧阴离子，超氧阴离子可以进一步转化为过氧化氢，然后与电极上的活性成分反应生成活性氧物种（ROS）参与 SMX 的降解。在很宽的近中性 pH 范围（5.6-9.0）内，SMX 可在 60 min 内几乎完全去除，并且该电极在十个循环后仍可达到 90.4%的去除率。自由基猝灭结果表明，超氧阴离子是 SMX 降解的主要物种。此外，还提出了 SMX 的可能降解途径。根据毒理学模拟的结果，在降解过程中污染物溶液的毒性呈现出下降的趋势。本研究为具有双金属活性成分的电极原位催化生成 ROS 以实现难降解有机污染物的高效降解提供了新的见解。
