ELECTROORGANIC REACTIONS ON ORGANIC ELECTRODES .18. ELECTROLYSIS USING COMPOSITE-PLATED ELECTRODES .7. PREPARATION OF ULTRAHYDROPHOBIC ELECTRODES AND THEIR ELECTROCHEMICAL PROPERTIES

Highly hydrophobic (i.e. ''ultrahydrophobic'') electrodes were prepare d by composite-plating nickel with fine particles of tetrafluoroethyle ne oligomer (TFEO). The maximum contact angle with water was 173-degre es when the composite-plated film contained TFEO in 20 vol.%. An elect rode composite-plated with fluorocarbon ((CF)n) particles also had a h igh contact angle, around 125-degrees, even when the content of (CF)n in the plated film was as low as 8 vol.%. These hydrophobic electrodes , Ni/TFEO and Ni/(CF)n, were found to give higher current efficiencies for the oxidation of alcohols, compared with those composite-plated w ith poly(tetrafluoroethylene) (PTFE), reported previously. However, in the reduction of benzyl halides, product selectivity was greatly affe cted by the hydrophobicity of cathodes.