School of Chemical and Environmental Engineering, China University of Mining and Technology of Beijing, Beijing, 100083, PR China.
Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, PR China.
Environ Sci Pollut Res Int. 2019 Nov;26(31):32165-32174. doi: 10.1007/s11356-019-06387-1. Epub 2019 Sep 7.
To achieve superior advanced oxidation processes (AOPs), transitional state activators are of great significance for the production of active radicals by HO, while instability limits their activation efficiency. In this study, density functional theory calculation (DFT) results showed that Cu exhibits excellent HO activation performance, with Gibbs free energy change (ΔG) of 33.66 kcal/mol, two times less than that of Cu (77.83 kcal/mol). Meanwhile, an electro-Fenton system using Cu plate as an anode was proposed for in situ generation of Cu. The released Cu with low-valence state can be well-confined on the surface of the exciting electrode, which was confirmed by X-ray photoelectron spectroscopy (XPS), Raman, and UV-vis spectroscopy. The hydroxyl radicals in this Cu-based electro-Fenton system were determined by the electron spin resonance (ESR). The nitrobenzene degradation ratio was greatly increased by 43.90% with the introduction of the proposed in situ electrochemical Cu generation process. Various characterization results indicated that the production of Cu was the key factor in the highly efficient Cu-based electro-Fenton reaction.
为了实现优越的高级氧化工艺（AOPs），过渡态激活剂对于通过 HO 产生活性自由基具有重要意义，而不稳定性限制了它们的激活效率。在本研究中，密度泛函理论计算（DFT）结果表明，Cu 表现出优异的 HO 激活性能，吉布斯自由能变化（ΔG）为 33.66 kcal/mol，比 Cu（77.83 kcal/mol）少两倍。同时，提出了一种使用 Cu 板作为阳极的电芬顿系统，用于原位生成 Cu。释放的低价态 Cu 可以很好地限制在激励电极的表面上，这通过 X 射线光电子能谱（XPS）、拉曼和紫外可见光谱得到了证实。该 Cu 基电芬顿系统中的羟基自由基通过电子自旋共振（ESR）确定。通过引入所提出的原位电化学 Cu 生成过程，硝基苯的降解率大大提高了 43.90%。各种表征结果表明，Cu 的生成是高效 Cu 基电芬顿反应的关键因素。
