کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6469890 | 1424106 | 2017 | 11 صفحه PDF | دانلود رایگان |
- The electrochemical reduction of Pb (II) in urea-BMIC is a diffusion-controlled one-step two-electron transfer process.
- Electrodeposition of Pb in urea-BMIC involves a 3D instantaneous nucleation and diffusion-controlled growth.
- Pb was prepared from urea-BMIC-PbO with optimized current efficiency of 96.17 % and energy consumption of 0.11Â kWh kg-1.
- Uniform, dense, and non-dendritic lead coating with grain size of 3 μm was prepared by potentiostatic electrolysis.
In this work, urea and 1-butyl-3-methylimidazolium chloride (urea-BMIC) deep eutectic solutions were used as electrolytes for electrodeposition of lead from lead oxide. The electrochemical behavior of Pb (II) ions was investigated by cyclic voltammetry, chronopotentiometry, and chronoamperometry techniques at 353-373 K. Cyclic voltammograms and chronopotentiograms indicate that the reduction of Pb (II) ions to Pb is a diffusion-controlled quasi-reversible process and it proceeds via one step two-electron transfer process at â0.38 V (vs. Ag). The diffusion coefficient of Pb (II) ions increases from 3.22 Ã 10â8 cm2 sâ1 to 1.49 Ã 10â7 cm2 sâ1 as temperature increases from 353 K to 373 K. The activation energy for diffusion is determined to be 83.93 kJ molâ1. In addition, results from chronoamperometry show that lead deposition involves in a three-dimensional instantaneous nucleation and diffusion-controlled growth. On the other hand, the electrodeposit on a Cu substrate was pure Pb as confirmed by X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). Scanning electron microscopy (SEM) image indicated that a uniform, dense, and non-dendritic coating with grain size of 3 μm in diameter was prepared by potentiostatic electrolysis at â0.4 V (vs. Ag). The optimized current efficiency (96.17%) and energy consumption (0.11 kWh kgâ1) was obtained by potentiostatic electrolysis at â0.4 V (vs. Ag) and 373 K from urea-BMIC deep eutectic solutions containing 0.072 mol dmâ3 PbO.
Journal: Electrochimica Acta - Volume 251, 10 October 2017, Pages 176-186