Electrolytical Obtaining of Ni-Mo Coatings with Polypyrrole

Abstract

Electrolytic coatings Ni-Mo with PPy were obtained by electrodeposition and electropolymerization from a galvanic bath containing Ni2+, MoO4 2–, ClO4 – ions and pyrrole (Py). The cyclic chronovoltamperommetric curve was used to determine the potential and current density of electrodeposition process. As the electropolymerization is anodic process while the electrodeposition is cathodic one, the electrode was working alternately as anode and cathode. The process was conducted under alternating potentiostatic or galvanostatic conditions. Comparative tests were carried out for Ni-Mo alloy. The results of structural investigation of the obtained coatings by the X-ray diffraction method show, the Ni-Mo layers are nanocrystalline solid solution of molybdenum in nickel (α phase), whereas the Ni-Mo+PPy coatings are characterized by decreased peaks coming from Ni-Mo base. Surface morphology of obtained Ni-Mo+PPy and Ni-Mo coatings was investigated by scanning microscope. It was stated, that the coatings obtained by alternating potentiostatic method exhibit multilayer character, whereas the coatings obtained under alternating galvanostatic conditions are characterized by the presence of Ni-Mo nanoagglomerates plated on polymer surface.