Macroporous MnO2 electrodes obtained by template assisted electrodeposition for electrochemical capacitors

Macroporous MnO2 electrodes prepared by template-assisted electrodeposition using spherical polystyrene colloidal particles are studied. The wettability of such electrodes by a LiClO4 aqueous electrolyte is measured by the contact angle technique. Cyclic voltammetry experiments are performed in order to evaluate the use of these electrodes for electrochemical capacitor applications. The specific capacity obtained is about 60% higher than that obtained for flat MnO2 surfaces showing that, in spite of the wettability being lower, some penetration of the electrolyte into the pores must occur, increasing the electroactive area with respect to the flat electrode. Furthermore, the macroporous electrode showed excellent electrochemical stability, with neither a capacitance decrease nor a loss of morphology, after 1000 cycles

Platinum nanoparticle-modified electrodes, morphologic, and electrochemical studies concerning electroactive materials deposition

The present work describes the synthesis of platinum nanoparticles followed by their electrophoretic deposition onto transparent fluorine-doped tin oxide electrodes. The nano-Pt-modified electrodes were characterized by voltammetric studies in acidic solutions showing a great electrocatalytic behavior towards H+ reduction being very interesting for fuel cell applications. Morphological characterization was performed by atomic force microscopy on different modified electrodes showing a very rough surface which can be tuned by means of time of deposition. Also, nickel hydroxide thin films were galvanostatically grown onto these electrodes showing an interesting electrochemical behavior as sharper peaks, indicating a faster ionic exchange from the electrolyte to the film