Chemical modification of diamond surfaces using a chlorinated surface as an intermediate state

Chemical modification of diamond powder surfaces was performed using chlorine chemisorption as an intermediate. We found OH, NH, and CF groups on the diamond surface. Chemisorbed species on the diamond powder surface were characterized by diffuse reflectance IR Fourier-transform spectroscopy, X-ray photoelectron spectroscopy, and temperature-programmed desorption spectroscopy. Hydrogen chemisorbed on the diamond surface is abstracted by chlorine above 250 degrees C, followed by the chemisorption of chlorine. Chlorine desorbs thermally from the diamond surface at approximately 300 degrees C. Hydroxyl groups are produced by treatment of the chlorinated diamond with water vapor at room temperature. Amino groups are produced by treatment of chlorinated diamond with ammonia at 425 degrees C. CF groups are produced by treatment of chlorinated diamond with CHF3 at 600 degrees C. Chlorine can easily chemisorb onto the diamond surface and easily desorb from the diamond surface. Using the chlorinated surface as an intermediate state, it is possible further to modify chemically the diamond surface.