Functions of Acetylene Black as an Oxygen Electrode

The relations between the surface properties or the pore structure of acetylene black for the electrode material of a gas diffusion electrode and the performance of electrochemical reduction of oxygen in an alkaline solution have been investigated. This work also describes an interesting electrochemical behavior of the electrode with oxygen plasma treated acetylene black. It was found that one of the most important factors controlling the performance of a gas electrode with acetylene black was the wettability of the electrode and that the fine pores below 0.2μm diameter in the electrode played an important role to formation of stable three phase zone at which the electrode reaction occurs. By oxygen plasma treatment, acetylene black surface changed from hydrophobic to hydrophilic and had large hydrogen peroxide decomposition ability by which the electrode performance was appreciably improved.