Size Distributions of Silver and Copper Crystals as a Function of Electrocrystallization Conditions on Glassy Carbon

Specific features and regularities of size distributions of crystalline nuclei are studied using the electrocrystallization of copper and silver on glassy carbon as an example. For a potentiostatic nucleation mode, with increasing overvoltage, a nonuniform size distribution approaches a uniform one. For a galvanostatic nucleation mode, the most probable nuclei size decreases with increasing current density and decreasing concentration of copper ions in solution, and the nuclei size distribution becomes more nonuniform due to a more pronounced non-steady-state nature of galvanostatic nucleation.     

Microrelief of Copper Deposit Surfaces: Effect of the Substrate Surface Microirregularities and Electrolysis Conditions

The growth of copper electrodeposits on glassy-carbon and copper electrodes from acidic sulfate electrolytes are investigated using statistical analysis of their surface microrelief. The regularities of variations in the root-mean-square deviation and the mean angle of microirregularities, the excess and the skewness of microrelief of the deposit surface during deposit growth are determined for various electrolysis conditions. At the initial stages of growth of deposits, their roughness substantially depends on the cathodic current density, concentration of copper ions, and crystalline heterogeneity of the cathode surface. An analysis of dependences of the mean angle of microirregularities, the excess, and the skewness of surface microrelief on the deposit thickness showed that the variations in the deposit structure and morphology become more pronounced with increasing cathodic current density and decreasing concentration of copper ions.