Investigation of intermediates by electron photoemission from metal into electrolyte solution

Abstract

During electron photoemission from an illuminated electrode into an electrolyte solution containing scavengers of hydrated electrons, stable and unstable products from reduction of the scavenger are formed in the vicinity of the electrode, which, at the same time, are intermediates of some electrochemical reactions. Thus, electron photoemission into acid solutions produces atomic hydrogen, that into nitrate solutions—the ion-radical NO^2–₃. In this type of experiment photoemission can be used, on the one hand, as a convenient source of intermediates and, on the other, as an instrument for measuring the rates of their chemical and electrochemical reactions.

Investigation of the simultaneous ionization and reduction of atomic hydrogen at a mercury electrode has shown one of the two reactions to be activationless (the transfer coefficient is zero). The rate constant of the decomposition of the unstable ion-radical NO^2–₃ in the solution bulk has been measured, as well as the transfer coefficient of its anodic oxidation on mercury.