State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
J Hazard Mater. 2012 Mar 30;209-210:414-20. doi: 10.1016/j.jhazmat.2012.01.044. Epub 2012 Jan 23.
The [Ni|Cu] microcell was prepared by mixing the Ni(0) and Cu(0) particles. The composition and crystal form were characterized by X-ray diffraction (XRD) and scanning electron microscope. The results evidenced the zero-valence metals Ni and Cu were exposed on the surface of particles mixture. The [Ni|Cu] microcell was employed to decompose chlorophenols in aqueous solution by reductive dechlorination. The dechlorination rates of chlorophenols by [Ni|Cu] were >10 times faster than those by [Fe|Cu], [Zn|Cu], [Sn|Cu], and [Fe|Ni] mixtures under the same conditions. [Ni|Cu] is different from other zero valent metals (ZVMs) in that it performed the best at neutral pH. The main products of chlorophenol dechlorination were cyclohexanol and cyclohexanone. The reduction kinetics was between pseudo zero-order and first-order, depending on the pH, concentration, and temperature. These results, combined with electrochemical analysis, suggested that Ni(0) acted as a reductant and catalyst in dechlorination reaction. The H* corridor mechanism from Ni(0) to Cu(0) was also proposed based on hydrogen spillover. The inhibition on the release of Ni(2+) by adding natural organic matters and adjusting pH was investigated.
[Ni|Cu] 微电池通过混合 Ni(0)和 Cu(0)颗粒制备。采用 X 射线衍射（XRD）和扫描电子显微镜对其组成和晶体形态进行了表征。结果表明，零价金属 Ni 和 Cu 暴露在颗粒混合物的表面。[Ni|Cu] 微电池被用于通过还原脱氯在水溶液中分解氯酚。在相同条件下，[Ni|Cu] 对氯酚的脱氯率比 [Fe|Cu]、[Zn|Cu]、[Sn|Cu] 和 [Fe|Ni] 混合物快 10 倍以上。[Ni|Cu] 与其他零价金属（ZVMs）不同，它在中性 pH 下表现最佳。氯酚脱氯的主要产物是环己醇和环己酮。还原动力学介于准零级和一级之间，取决于 pH 值、浓度和温度。这些结果与电化学分析相结合表明，Ni(0)在脱氯反应中充当还原剂和催化剂。基于氢溢出，还提出了从 Ni(0)到 Cu(0)的 H*走廊机制。研究了添加天然有机物和调节 pH 值对抑制 Ni(2+)释放的影响。
