Electrochemical study and recovery of Pb using 1:2 choline chloride/urea deep eutectic solvent: A variety of Pb species PbSO4, PbO2, and PbO exhibits the analogous thermodynamic behavior
Electrochemical study and recovery of Pb using 1:2 choline chloride/urea deep eutectic solvent: A variety of Pb species PbSO4, PbO2, and PbO exhibits the analogous thermodynamic behavior
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DOI：
10.1016/j.electacta.2016.08.053
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发表时间：
2016-10-01
影响因子：
6.6
通讯作者：
Sun, I-Wen
中科院分区：
文献类型：
--
作者：
Liao, Yu-Shun;Chen, Po-Yu;Sun, I-Wen
不溶于水的PbSO4、PbO2和PbO以1:2的摩尔比溶于氯化胆碱/尿素深共熔溶剂（ChCI/尿素DES）。有趣的是，由PbO2制备的溶液表现出与PbSO4和PbO几乎相同的电化学行为，这表明无论引入何种Pb化合物，都可以在DES中形成Pb（II）。Pb（II）的电化学还原是一个不可逆的过程，涉及扩散控制生长的三维（3D）瞬时成核。由扩散系数随温度的变化可知，PbSO4和PbO2的扩散活化能分别为33.7和34.1 kJ mol（-1）。采用恒电位和恒流两种方法实现了铅的电沉积。铅镀层的表面形貌受外加电位和电流的影响较大。Pb电沉积的库仑效率大于90%。本文还研究了含三种不同铅源混合物的湿式DES中铅的电沉积。XRD分析证实了镀层由金属Pb组成。(C) 2016 Elsevier Ltd.版权所有。
Water-insoluble PbSO4, PbO2, and PbO are fairly soluble in choline chloride/urea deep eutectic solvent (ChCI/urea DES) in 1:2 molar ratio. Very interestingly, solution prepared from PbO2 exhibits the almost identical electrochemical behavior as those from PbSO4 and PbO, indicating that Pb(II) is formed in the DES regardless of what Pb compound is introduced. The electrochemical reduction of the Pb(II) species is determined as an irreversible process, and involves the three-dimensional (3D) instantaneous nucleation with diffusion-controlled growth. From the dependence of the diffusion coefficient on temperature, the activation energy for diffusion of PbSO4 and PbO2 is determined to be 33.7 and 34.1 kJ mol(-1), respectively. Electrodeposition of Pb was achieved potentiostatically and galvanostatically. The surface morphology of Pb deposits significantly depends on the applied potential and current. The coulombic efficiency of Pb electrodeposition is higher than 90%. Electrodeposition of Pb from a wet DES containing a mixture of three different Pb sources is also investigated. The XRD analysis confirmed that the electrodeposits consisted of metallic Pb. (C) 2016 Elsevier Ltd. All rights reserved.