Electrochemical studies of C-60/Pd films formed by the reduction of C-60 in the presence of palladium(II) acetate trimer. Effects of varying C-60/Pd(II) ratios in the precursor solutions

Cyclic voltammetric studies of the electrochemical formation and redox prop erties of Csd Pd films are reported. Films used in this work are generated under multicyclic scans in an acetonitrile/toluene (1:4, v/v) mixture conta ining fullerene C-60 and palladium(II) acetate trimer as the film precursor s and tetra(n-butyl)ammonium perchlorate as supporting electrolyte. The str ucture and electrochemical properties of the deposited layers depend on the relative concentrations of the precursors (C-60 and {Pd(OAc)(2)}(3)) prese nt in the growth solution. In the presence of excess palladium(II) acetate trimer, palladium, as well as the redox active film, is deposited, as shown by electrochemical studies of the behavior of the modified electrodes towa rd hydrogen evolution and palladium oxidation in aqueous acidic solution. A t very negative potentials, all of the films decompose which is presumed to be due to the repulsive interaction between negatively charged C-60 center s and mechanical strain induced by the incorporation of cations from the su pporting electrolyte in the film. However, the stability of the films depen ds on the C-60 to Pd(II) ratio in the solution from which the film was prep ared. The presence of deposits of palladium within the film changes the mec hanical and electrochemical stability of the films and also alters the reve rsibility of the charging processes.