Reflectivity change potential dependence

B40 panels were also subjected to heat treatment. As shown in Figure 2, no dependence of the open circuit potential on post-thermal treatment temperature is observed. This suggested that the open circuit potential measurements reflected changes at the coating/B40 panel interface and not in the B40 panel alone. 

For instance, in situ Fourier transform infrared (FTIR) spectroscopy has been used by Faguy etal. [176] to study the potential-dependent changes in anion structure and composition at the surface of Pt(lll) electrodes in H 804 -containing solutions. From the infrared differential normalized relative reflectance data, the maximum rate of intensity changes for three infrared bands can be obtained. Two modes associated with the adsorbed anion... 

The work function is an important parameter that influences the catalytic behavior of the metal surface. The work function effect has been clearly demonstrated in the case of the NEMCA (non-Faradaic electrochemical modification of catalytic activity) effect, where it has been shown experimentally that catalytic reaction rates depend exponentially on the work function change of the metal surface ([126-130] and references therein). Work function changes in the case of NEMCA are caused by backspillover of anions on the metal surface, and they reflect changes in the surface potential. 

Potential-dependent reflectance changes at an electrode may also be a conseqnence of an electrode reaction that changes the absorption coefficient of a snrface fdm or of the solntion adjacent to the snrface. The more general term potential-modulated reflectance spectroscopy (PMR) is nsed to describe the experimental method in this case. The apparatns is the same as that nsed for EER, bnt the origin and characteristics of the PMR response are different (see, e.g.. Walker et al, 1998). 

Fig. 37. Potential dependence of the reflectivity change obtained with 0.1 M NaC104—80% ethanol solutions containing (A) 4.3 x lO M CoQ, (B) 4.7 x 10 M squalene, and (C) 8.1 x 10 M duroquinone. The arrow shows the reduction potential.

Fig. 41. Potential dependence of the reflectivity change obtained with 0.1 Af NaC104 solutions containing (a) acetylcholine chloride (b) choline chloride (c) NaCl (d) tetramethylammonium perchlorate. Concentrations (O) 1.1 X 10 (A) 1.0 X 10 ( ) 7.6 X 10 ( ) 3.8 x 10 M. (From Kusu and Taka-mura, 1984, with permission.)...

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