Electrocatalytic activity for hydrogen evolution of polypyrrole films modified with noble metal particles

Polypyrrole (Ppy) films of various thicknesses contg. particles of noble metals such as Pt, Ru and Ir were electrosynthesized on the surface of austenitic stainless steel (Ss). Two different approaches were applied: (i) electrodeposition of a polymer film from a soln. already contg. an anionic metal complex, followed by potentiodynamic or galvanostatic redn.; and (ii) presynthesized Ppy films modified by galvanostatic electrodeposition of noble metals from solns. of the metal complexes. Surface morphol. and compn. of the resulting layers were studied by means of SEM and XPS. The electrocatalytic activity of the modified electrodes for the hydrogen evolution reaction (her) was tested in 0.05 M H2SO4 by means of potentiodynamic techniques (0.5 mV s-1).