Electrochemical Studies of C60/Pd Films Formed by the Reduction of C60 in the Presence of Palladium(II) Acetate Trimer. Effects of Varying C60/Pd(II) Ratios in the Precursor Solutions

Abstract

Cyclic voltammetric studies of the electrochem. formation and redox properties of C60/Pd films are reported. Films used in this work are generated under multicyclic scans in an acetonitrile/toluene (1:4, vol./vol.) mixt. contg. fullerene C60 and palladium(II) acetate trimer as the film precursors and tetra(n-butyl)ammonium perchlorate as supporting electrolyte. The structure and electrochem. properties of the deposited layers depend on the relative concns. of the precursors (C60 and {Pd(OAc)2}3) present in the growth soln. In the presence of excess palladium(II) acetate trimer, palladium, as well as the redox active film, is deposited, as shown by electrochem. studies of the behavior of the modified electrodes toward hydrogen evolution and palladium oxidn. in aq. acidic soln. At very neg. potentials, all of the films decomp. which is presumed to be due to the repulsive interaction between neg. charged C60 centers and mech. strain induced by the incorporation of cations from the supporting electrolyte in the film. However, the stability of the films depends on the C60 to Pd(II) ratio in the soln. from which the film was prepd. The presence of deposits of palladium within the film changes the mech. and electrochem. stability of the films and also alters the reversibility of the charging processes.