Preparation of Thin-film Electrodes

Thin-film electrodes that exhibit the SEIRA effect can be deposited on the total-reflecting plane of the prism by vacuum evaporation or electroless plating of the desired metal. Electrochemical deposition cannot be used for non-doped (and thus non-conducting) Si windows, but is possible for Ge. 

Vacuum-evaporated very thin ( 20 run) Au and Ag electrodes suitable for SEIRAS show pale blue to purple colors, while chemically deposited film electrodes show the colors of the corresponding massive metals and are as shiny as a well-polished surface. Both thin-film electrodes have enough conductivity for electrochemistry. These film electrodes are usually polycrystaUine. In the case of Au films, 

SEIRAS usually gives spectral features of the adsorbed molecules the same as those observed by IRAS on massive bulk electrodes, but the band intensity and 

Transition metal electrodes prepared by sputtering and electrochemical deposition often show derivative-hke (i.e., bipolar) [17, 34—38] or negative absorption (anti-absorption) bands [46-50]. Spectral features change from normal absorption to anti-absorption through bipolar shapes with increasing amount of the metal deposited [17]. The bipolar band shape was ascribed to a Fano-type resonance of electronic interactions between molecular vibrations and the metal [34, 35]. The anti- 

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To check an electroactivity of catalysts, cyclic voltammetry method for a three-electrode cell system was performed. We had prepared a working electrode by coating the catalyst powder mixed with Nafion polymer onto a glassy carbon electrode. The preparation of thin film electrodes followed the previous researchers method [74-76]. Electrochemical impedance spectroscopy (EIS) measurements were studied by means of above electrochemical device coupled with FRA2 module (Eco Chemie, Netherlands) in a frequency range of 1 MHz - 0.1 Hz. 

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