The surface properties and the electrochemical behavior of a fluorinated boron-doped diamond (F-BDD) electrode prepared by plasma treatment in CF4-He mixture has been studied by X-ray photoelectron spectroscopy and cyclic voltammetry in acidic media. The results have shown the presence of carbon-fluorine bonding (C-CF and C-F) on the surface of F-BDD, which made the surface more hydrophobic. It was also found that hydrogen evolution was shifted to more cathodic potentials for fluorinated diamond, as compared with untreated BDD. Finally, the higher cathodic overpotential for hydrogen evolution permitted nickel deposition and nitrate reduction. (C) 2003 The Electrochemical Society.