Nucleation kinetics and contact angles of silver clusters electrodeposited on indium tin oxide surfaces

详细信息    查看全文

• 作者：D. Branco P.^a ; ¹ ; K. Saavedra^a ; ² ; M. Palomar-Pardavé ; ^b ; C. Borrá ; s^a ; J. Mostany^a ; ^{jmosta@usb.ve" class="auth_mail" title="E-mail the corresponding author} ; B.R. Scharifker^a ; ^c ; ^{benjamin@usb.ve" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Electrocrystallization ; Nucleation ; Kinetics ; Contact angle ; Optically transparent electrode
• 刊名：Journal of Electroanalytical Chemistry
• 出版年：2016
• 出版时间：15 March 2016
• 年：2016
• 卷：765
• 期：Complete
• 页码：140-148
• 全文大小：820 K

文摘

The nucleation rate and the number density of nucleation sites, as well as the contact angle of silver clusters growing under diffusion control, have been determined with single-step potentiostatic experiments, from the electrical current and optical transmittance during electrocrystallization of silver on optically transparent indium tin oxide electrodes. It was found that silver grows at overpotentials as crystallites with an aspect corresponding to an effective contact angle with the indium tin oxide surface of ca. 13°. Comparison with results obtained from ex situ atomic force microscopy analysis suggests that electrodeposited nuclei undergo conformational relaxation at open circuit, leading to significantly higher equilibrium contact angles. The results obtained indicate that while the contact angles measured during growth at overpotentials have no bearing on the values of nucleation rates determined from the electrical and optical responses to potential steps, they lead to lower number densities of sites, in relation to values corresponding to the growth of hemispherical centers. Implications of the results obtained for the clustering of silver atoms leading to the electrocrystallization process are also discussed.