The deposition of metal nanoparticles (such as Ag, Cu, Au, Pd, and Pt) on b
oron-doped, polycrystalline diamond thin films grown on silicon substrates
was investigated using Raman spectroscopy, scanning electron microscopy, X-
ray photoelectron spectroscopy, and X-ray diffraction. Nanometer-size metal
particles with preferred crystalline textures can be spontaneously deposit
ed on the diamond thin film after a simple immersion in an acidic solution
containing metal ions or metal complex ions. The size and distribution of m
etal deposits can be controlled by adjusting the metal ions concentration,
the solution acidity, and the deposition time. The diamond/silicon interfac
ial ohmic contact was found to be the critical factor for achieving the obs
erved spontaneous metal deposition on the diamond surface. Significant enha
ncement of hydrogen evolution activity was observed on a diamond electrode
modified by 9% coverage of Pd nanoparticles. The results demonstrate a nove
l route for depositing nanometer-size metal catalysts on a highly corrosion
resistant and dimensionally stable polycrystalline diamond support.