The splitting of water in a solution containing 1.0mol·dm^-^3KOH is studied based on the semiconductor photoanodes, n/n^+-Si, by alkali-etching and modifying with Ni/Pt dual metal layer. The optimization photocurrent of 65.2mA·cm^-^2 for oxygen evolution is observed at 1.0V (vs. HgO/Hg electrode) with a light intensity of 90mW·cm^-^2. The photoanodes are stable during oxygen continuous evolution for 200 hours. Electrode surface analysis is carried out by using Electron Spectroscopy for Chemical Analysis (ESCA) system.

Key words: PLATINUM, NICKEL, PHOTO-ELECTROCHEMISTRY, PHOTOELECTROD, MODIFIED ELECTRODE, SURFACE MODIFICATION