Morphological and electrochemical characterisation of graphite electrodes coated with SPANI and Ni-cyclam

The preparation of the composite graphite–sulphonated polyaniline (SPANI)–Ni-cyclam was investigated with the purpose of dispersing a catalyst in a conducting matrix that allows a better electronic transfer from the surface of the electrode towards the reaction site. The graphite is a material with a high porosity, big area and cheaper than other materials. The electrochemical and morphological characterisations show that the best conditions for obtaining SPANI over graphite were reached with an anodic limit of 1,000 mV in H₂SO₄. The deposit of the Ni-cyclam over graphite–SPANI in basic medium allows the formation of a spongy and open material, which permits better accessibility to the catalytic sites, showing good catalytic properties. These results illustrate that the importance relays on the morphology and dispersion of the catalyst and not on the amount of catalytic material present in the composite. The electrocatalytical properties Ni-cyclam over graphite–SPANI was studied for the methanol oxidation in basic medium.