Electrolysis. Copper deposition at different concentrations of electrolyte. (original) (raw)

Electrodeposition and characterisation of copper deposits from non-cyanide electrolytes

Acid copper plating on mild steel metallic foil is very difficult due to the galvanic displacement reaction of copper on mild steel. This can be avoided by using a suitable complexing agent. The present investigation deals with the electrodeposition of copper from non-cyanide electrolytes using glycerol as complexing agent in an alkaline medium in the presence of gelatin, anisaldehyde, imidazole and peptone as additives. These additives influence the morphology of the deposited copper films by reducing the grain size, ensuring smoothness and brightness of the films. The additives also improve the throwing power of the depositing electrolytes. The X-ray diffraction pattern obtained for the electrodeposited copper film shows a polycrystalline and face centred cubic structure. The crystal size of the copper film was calculated using Debye Scherrer's formula. A uniform and pin hole free surface morphology was observed under SEM, which revealed the grain refining brought about by the additives.

Autocatalytic deposition of copper from modified electrolytes and its characteristics

The electroless deposition process of copper plating consisting of TEA and EDTA as complexing agents, paraformaldehyde as reducing agent, and 2-mercaptobenzothiozole as stabilizer and gelatin and animal glue as additives was investigated. The stability of the electroless copper solution was monitored by measuring the absorbance of the solution with a UV-Visible spectrophotometer and the solution was quite stable up to 15 h. The adhesion of copper films on mild steel foil was assessed by standard bend test and exhibited good adhesion. The XRD results indicate that the copper films have a (111) texture. Moreover, the additives suppress the predominant (111) plane crystal growth and increase the rate of (220) texture crystal growth. The crystal size of the copper films was calculated using the Scherrer formula from the predominant peak. SEM and AFM studies reveal that these two additives modify the crystal structure, grain size and surface morphology of the copper films. The cyclic voltammetry studies reveal that the additives are adsorbed on the electrode surface and inhibit the rate of deposition. Potentiodynamic polarization and electrochemical impedance studies reveal that the deposits produced in the presence of additives display higher corrosion resistance.