为了能在室温下从氧化铅中电化学提取铅,合成一种新的电解质尿素-1-乙基-3-甲基氟化咪唑(urea-[EMIM]F)以溶解氧化铅,并研究铅在此电解质中的电化学行为.电化学提取前,研究该电解质的密度、黏度和电导率.采用循环伏安法、计时电流法和恒电位电解技术研究铅在尿素-1-乙基-3-甲基氟化咪唑中的电化学行为.结果表明:采用该电解质可在室温下从氧化铅中电化学提取铅;铅的还原遵循一步两电子的准可逆过程和三维(3D)连续成核模型;随着温度的升高,铅还原的起始电位逐渐向阳极移动;在353 K下Pb(II)的扩散系数为6.88×10-10 cm2/s;对尿素-1-乙基-3-甲基氟化咪唑体系进行恒电位电沉积后,获得球状铅颗粒.
To electrochemically extract Pb from PbO at room temperature, a new electrolyte, urea-1-ethyl-3- methylimidazolium fluoride (urea-[EMIM]F), was synthesized to dissolve PbO. Afterwards, the electrochemical behavior of Pb in this electrolyte was studied. The density, viscosity and conductivity of this electrolyte were investigated before electroextraction. The electrochemical behavior of Pb in the urea-[EMIM]F system was recorded via cyclic voltammograms, chronoamperometry and potentiostatic electrolysis. The results illustrate that Pb can be electrochemically extracted from PbO in this system at room temperature and that Pb reduction involves a quasireversible process and follows a one-step and two-electron transfer process. The reduction of Pb proceeds with a three-dimensional (3D) progressive model. With an increase in temperature, the onset potentials for Pb reduction shift anodically. The diffusion coefficient of Pb(II) is determined to be 6.88×10-10 cm2/s at 353 K. Additionally, spherical Pb particles are obtained after electrodeposition in the urea-[EMIM]F system via potentiostatic electrolysis.