Electrodeposition of Ag/CNT Composite Films from Iodide Plating Baths

Abstract

Ag/carbon nanotube (CNT) composite films were prepared by electrodeposition from non-cyanide baths. An iodide bath and multiwalled CNTs were used. The stability of the iodide bath under ambient conditions at various pH levels was examined, along with the changes in visual appearance, pH, and triiodide ion (I3 −) concentration. The electrodeposition was conducted under galvanostatic conditions using iodide baths with and without CNTs. The microstructure of the Ag and Ag/CNT composite films was characterized, and the hardness, electrical conductivity, and coefficient of friction of the films were measured. The iodide bath was stable at higher pH levels under ambient conditions. The obtained Ag/CNT composite films exhibited a compact structure, and CNTs were homogeneously distributed in the interior of the deposited Ag matrix. The CNT content in the deposits increased with increasing CNT concentration in the plating bath. The hardness of the Ag/1.2 mass%-CNT composite film was 63.2 HV, which was slightly greater than that of the Ag film (60.4 HV). The resistivity of the composite film was 1.9 μΩ cm, which was slightly higher than that of the pure Ag film (1.8 μΩ cm). The coefficient of friction of the composite film was lower than that of the Ag film.