Electrodeposition of bismuth from nitric acid electrolyte

The electrodeposition of Bi from acidic nitrate solution was examined. Bismuth deposition was determined to be quasi-reversible on Au, with a current efficiency of 100%, based on integration of deposition and stripping voltammetric waves. No interference from nitrate reduction was found on Bi and Au, whereas nitrate reduction occurred on W and Cu electrodes. Analysis of current-time transients clearly shows nucleation on Au to be instantaneous. Field emission SEM revealed nodular deposits with moderate surface roughness. Nodule size varied from 1 to 5 mu m depending on deposition potential and deposit thickness. X-ray diffraction (XRD) patterns for all deposits were indexed to rhombohedral bismuth. The deposits showed fairly strong (012) crystallographic texture at high deposition overpotentials. (c) 2007 Elsevier Ltd. All rights reserved.