Lead-free galvanic oxygen sensors — A conceptual approach

Within this paper we present a thermodynamic methodology for the selection of non-toxic metals which could be used as lead-free consumable anodes in electrochemical galvanic oxygen sensors. Starting from thermodynamic nobility theory, metals like copper, bismuth or antimony are proposed to replace lead in future galvanic O₂ sensors. The thermodynamic theory provides voltage windows which increase from copper (0.7 V), to bismuth (0.857 V) and antimony (1.076 V). The experimental voltage windows are smaller than the theoretical ones, but these experimental values increase in the same order from Cu, to Bi and Sb, as predicted by our methodology.