Palladium-palladium oxide pH electrodes

Electrochemical evidence of two-dimensional surface compounds of heterocyclic molecules at sulphur-covered gold and platinum

Effect of sulphur-adlayer preparation on self-assembled monolayers of phenothiazines at polyoriented platinum electrodes

Photogalvanic cells: Part XII. The dark electrochemistry of the iron-thionine system at platinum

: Multiple specular reflection is the basis of a new thin layer spectro-electrochemical cell which does not use optically transparent electrodes, the optical sensitivity of which exceeds that of cells using transparent electrodes by a factor of several hundred. As a result, the ability to detect short-lived intermediates and weakly absorbing species in spectroelectrochemical studies is much improved. Absorbance changes less than 5 x 10 to the minus 5 absorbance units per electrode reflection are readily observed. A cell 4cm long with a 120 micrometers spacing, operated to give approximately 330 reflections, was used to monitor optically the reduction of methylene blue and the reoxidation of the leuco form at concentrations as low as 5 x 10 to the minus 7M. For both reactions, the absorbance is linear with square root of t from 10 ms to ca 3 s, and the magnitude agrees well with values calculated from the geometry of the optical path. Among the advantages of the new technique are greatly increased optical sensitivity and the ability to use electrode materials which are not transparent. (Author)

Spectroelectrochemical monitoring of electrode reactions by multiple specular reflection spectroscopy

The reflection of light from an electrode surface was investigated using a multiple-reflection and a single-reflection cell. The single-reflection studies were combined with a modulation of the reflectivity of the interface. The potential drop across the electrolytic double layer was modulated. The electro-reflection technique enables one to investigate the adsorbed layer without interference by light absorption in the electrolyte. Results are reported for the adsorption of methylene blue on a platinum electrode.

W. J. Plieth

Papers

Studies of adsorbed states at the electrode/electrolyte interface by specular reflection of light