Polyaniline-Modified Electrodes for the Anode of the Direct Ascorbic Acid Fuel Cell

摘要

A conductive polymer, polyaniline (PANI), was electrodeposited on a glassy carbon electrode. Using this PANI-modified electrode, L-ascorbic acid was electro-oxidized, and the electrocatalytic activity of PANI was evaluated for 1) the effect of preparation conditions of PANI, 2) the durability of catalytic action and 3) the effect of metal deposition. The highest electrocatalytic activity was obtained with SO_4~(2-)-doped PANI. The durability of the catalytic action was significantly improved by the PANI modification. The metal deposition deactivated rather than activated the PANI-modified electrode. The PANI-modified electrode was regarded as a promising anode for the direct ascorbic acid fuel cell because it was known to be a highly active toward the electro-oxidation of L-ascorbic acid for a long time and was entirely free from harmful heavy metals and expensive Pt.