Cathodic Modification in Aqueous Phosphate-Molibdate Solutions of Chitosan as a Way of Enhancing Hydride-Forming and Hydride-Accumulating Properties of Titanium
The electrochemical behavior of Ti electrode in aqueous solutions containing Na<sub>2</sub>MoO<sub>4</sub> + H<sub>3</sub>PO<sub>4</sub> + chitosan was investigated by methods of potential - time (E-t) curves at cathodic polarisation in galvanostatic mode, currentless chronopotentiometry, optic microscopy, X-ray spectral analysis of surface and determining roughness by measuring the wetting angle. It was found that on Ti electrode in the time of cathodic treatment in aqueous solutions including Na<sub>2</sub>MoO<sub>4</sub> + H<sub>3</sub>PO<sub>4</sub> + chitosan oxidation of titanium by the adsorbing anions Mo(VI) and the incorporation of sodium and hydrogen cations into cristallic titanium lattice through the forming on the surface the layer of chitosan polymer intercalated by polymolibdate and polyphosphatemolibdate ions with the forming of the substances Na<sub>6+x</sub>Ti<sub>n</sub>Mo<sub>7-n</sub>O<sub>24</sub> (chitosan) and Na<sub>7+y</sub>Ti<sub>2</sub>(MoO<sub>4</sub>)<sub>y</sub>(PO<sub>4</sub>)<sub>3+y</sub> (chitosan) took place. The adsorption of polyanions and the formation of the layer of the indicated composition occurred already without current.