Electrodeposition of lanthanum hydroxide–polyethylenimine films

Composite films consisting of lanthanum hydroxide and polyethylenimine (PEI) were obtained via cathodic electrodeposition. Films up to 5 μm thick were obtained on Ni, Pt, graphite and carbon felt substrates. By varying the concentration of PEI in solutions and deposition time, the amount of the deposited material and its composition could be controlled. The deposits were studied by thermogravimetric (TG) analysis and scanning electron microscopy (SEM). A mechanism of electrochemical intercalation of the cationic polymer into lanthanum hydroxide deposits is discussed.