AVS 49th International Symposium
    Surface Science Wednesday Sessions
       Session SS-WeP

Paper SS-WeP12
Adsorption Behavior of L-cysteine on Transition Metals (Ni, Cu) in Aqueous or Methanol Solution Studied by S K-edge NEXAFS and XPS

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Surface Science Poster Session
Presenter: S. Yagi, Nagoya University, Japan
Authors: S. Yagi, Nagoya University, Japan
Y. Matsumura, Nagoya University, Japan
Y. Nakano, Nagoya University, Japan
E. Ikenaga, Hiroshima University, Japan
S.A. Sardar, Hiroshima University, Japan
J.A. Syed, Hiroshima University, Japan
K. Soda, Nagoya University, Japan
E. Hashimoto, Hiroshima University, Japan
K. Tanaka, Hiroshima University, Japan
M. Taniguchi, Hiroshima University, Japan
Correspondent: Click to Email
Adsorption behavior of a sulfur-containing amino acid molecule on transition metal surface has been interested in a bio-catalytic and surface reaction fields. In this study, we have studied the adsorption behavior of the L-cysteine amino acid [HSCH@sub 2@CH(NH@sub 2@)COOH] on polycrystalline Ni and Cu surfaces by sulfur K-edge Near Edge X-ray Absorption Fine Structure (NEXAFS) and sulfur 1s X-ray Photoelectron Spectroscopy (XPS) techniques. The sample was prepared by scratching the substrate in the aqueous or methanol solution of the L-cysteine at room temperature. In the NEXAFS spectra, a significant difference of the first peak (1s-to-@sigma@*(S-C)) shape was obtained between two kinds of Ni samples, which were prepared in the aqueous and methanol solutions. Curve-fitting results of the NEXAFS spectra indicates that the L-cysteine on Ni in the aqueous solution dissociates. On the other hand, the L-cysteine in the methanol solution on Ni does not dissociate. Keywords: NEXAFS, XPS, L-cysteine, adsorption behavior, Ni, Cu, aqueous solution, methanol solution.