Influence of supporting electrolytes on photoelectrochemical stability of lead oxide in K₄Fe(CN)₆ solution^†

Abstract

Photoelectrochemical (PEC) stability of lead oxide (PbO_n) in Fe(CN)₆^-4 solution with alkali halides at <i>p</i>H 9.2 has been studied. Among the alkali halides studied, KI (0.1<i>M) </i>enhances the stability of PbO_n by 80%. This stability enhances further if solution is made from a saturated solution of PbO. A model is developed to explain the role of KI in suppressing the photocorrosion of PbO_n. A special arrangement is designed for illuminating disc/ring electrode assembly of rotating rind disc electrode (RRDE) as well for electrode of a PEC cell to minimize the loss of light intensity due to its absorption by coloured solution. Alkali halides MX (M = Li, Na, K and Cs; X = Cl, Br, and I), have been used for this study.