Lead electrodeposition from alkaline solutions containing xylitol
(1. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Resources Chemistry of Nonferrous, Central South University, Changsha 410083, China;
3. School of Metallurgical Science and Engineering, Central South University, Changsha 410083 , China)
2. Key Laboratory of Resources Chemistry of Nonferrous, Central South University, Changsha 410083, China;
3. School of Metallurgical Science and Engineering, Central South University, Changsha 410083 , China)
Abstract: The electrodeposition of lead in alkaline solutions containing xylitol (1, 2, 3, 4, 5-pentahydroxypentane) was studied. The lead electrodeposition and the chemical stability of xylitol in alkaline solutions were investigated by cyclic voltammetry. Apparent activation energy, apparent transfer coefficient and exchange current density were obtained by linear sweep voltammetry. Initial stages of lead electrocrystallization were determined by chronoamperometry. Voltammograms of a AISI 316 stainless steel electrode in xylitol solution exhibit no current in the potential range of −1.3 V to 0.75 V (vs Hg/HgO), implying that xylitol is stable to oxidation and reduction. The apparent activation energy, apparent transfer coefficient and exchange current density were calculated to be 35.15 kJ/mol, 1.56 and 9.65×10−5 A/m2. Analysis of the chronoamperometric responses implies three-dimensional growth of nuclei, with the type of nucleation depending on overpotential.
Key words: lead; xylitol; electrodeposition; cyclic voltammetry; nucleation; chronoamperometry