IN-SITU PHOTOELECTROCHEMICAL CHARACTERISTICS OF THE N-CDTE-VERTICAL-BAR-ACETIC ACID-SOLUTION INTERFACE BY FTIR-ATR

Fourier transform LR attenuated total reflection (FI?R-ATR) spectrosco py has been used to investigate the adsorption of acetic acid on the n -CdTe photoelectrode in aqueous and non-aqueous solutions. Electromodu lated spectra associated with different adsorbates are observed. Aceto nitrile as a solvent is adsorbed on the CdTe surface. A blue shift of nu(C=N) (2460 cm(-1)) is observed. Illumination affects the blue shift of the adsorbed acetonitrile. Current oscillations were observed unde r illumination in the anodic region of the cyclic voltammogram. Acetic acid, which is a bidentate ligand, is adsorbed on the CdTe surface. I t reduces the blue shift caused by acetonitrile. The absorption intens ities of the O-H bending and C-O stretching modes change under illumin ation. The photo-Kolbe reaction is present. In aqueous solution, the i ntensity of the C-O bending mode increases when the electrode potentia l becomes more positive. The adsorbent effects and electrochemical Sta rk effects related to the different adsorption models are discussed.