Electrode, dropping mercury transparent

Substrates DME = dropping mercury electrode FTO = fluorine-doped tin oxide G = graphite GC = glassy carbon GrC = graphic carbon ITO = indium tin oxide-coated glass SC = single crystals SS = stainless steel TCO = transparent conducting oxide VC = vitrious carbon. Miscellaneous ECALE = electrochemical atomic layer epitaxy ED = electrodeposition ML = monolayer RT = room temperature SMD = sequential monolayer deposition V = vacuum. 

Hydrogen fluoride can be handled in apparatus of suitable metals (copper, nickel, magnesium, or aluminum, which all form a protective fluoride coating, or platinum), or plastic materials [especially polypropylene. Teflon, and polyvinylidene fluoride (Viton)] polychlorotrifluoroethylene (Kel-F) can be made into transparent windows. A capillary for a dropping mercury electrode may be made from Teflon [307]. Hydrogen fluoride is obtained commercially in steel cylinders in a purity of 99.5%. The impurities may be removed by distillation [308] or electrolysis [309]. During the electrolytic removal of water the explosive FoO is formed, which must be taken into consideration [305]. 

So far, five types of mercury electrode have been used in specular reflection measurements (i) hanging mercury drop electrode (HMDE) [38, 39], (ii) mercury film deposited on a platinum or gold substrate [40-42], (iii) mercury pool electrode with or without an amalgamated platinum ring guide [43, 44], (iv) mercury drop bottom electrode placed on the optical window [45—47], and (v) mercury drop bottom electrode placed on an underlying ion-conductive optically transparent polymer film [48]. To avoid the difficulty due to mechanical vibration and shape change, the mercury drop bottom electrode would be useful. 

The use of a mercury drop bottom electrode placed on an underlying Nation fihn in ER measurement was demonstrated for the reaction of heptyl viologen incorporated in a Nafion film (Fig. 2.13) [48], A mercury drop was placed on a Nation 117 tihn of thickness 0.175 mm. The transparent nature of the Nafion as weU as the high conductivity for cations through its film made it actually possible to measure the ER spectrum of the redox reaction of heptyl viologen with a perpendicular incidence of the hght to the mercury electrode surface through the cell bottom window and the Nafion fihn. 

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