Ionic Mass Transfer Rate Accompanying Pulsed Current Electrodeposition of Silver

抄録

Transient mass transfer rate of Ag⁺ ion associated with natural convective electrolyte flow developing along the vertical plane electrodes immersed in a stagnant AgNO₃ aqueous electrolyte solution is numerically analyzed under both direct and pulsed current conditions. The cathodic concentration profile of Ag⁺ ion caused by silver electrodeposition was measured by the holographic interferometer. Calculated results are compared with the measured values. Under direct current condition, it is found that quantitative agreement between calculated and measured results is obtained at the lower current density, while an obvious deviation is noticed at the higher one due to the laser beam deflection effect as well as the concentration dependence of transport properties. Additionally, it may be related to the fact that the effective cathode surface area apparently increases due to the roughening of the cathode surface by silver electrodeposition. Under pulsed current condition, reasonable agreement is obtained even at the higher pulse current density. It may be ascribed to the fact that pulse electrolysis reduces the nodular growth, edge build up, and surface roughness development.