Manganese oxide electrodes are synthesized by anodic deposition on Au coated Si substrates from acetate-containing aqueous solutions. By changing the deposition parameters including deposition current density, electrolyte composition, pH and temperature, a series of nanocrystalline manganese oxide electrodes with various morphologies (non–uniform continuous coatings, rod–like structures, aggregated rods and thin sheets) is obtained. Detailed microstructural characterization of as-deposited electrodes is conducted using scanning electron microscopy (SEM).
Electrochemical analysis using cyclic voltammetry showed that manganese oxide electrodes with rod–like and thin sheet morphology exhibit enhanced electrochemical performance by improving manganese oxide utilization. The highest specific capacitance (~230 F g−1) and capacitance retention rates (~88%) are obtained for manganese oxide thin sheets after 250 cycles in 0.5M Na2SO4 at 20 mV s−1.