On the pH sensitivity of the galvanic tungsten–water interaction product

Abstract

Abstract In this study it has been found that the potential of a galvanic tungsten–water interaction product (GTWIP) is more negative than that of the commercial W or high-purity monocrystalline W potential. It was shown that the GTWIP potential is a linear function of pH, and is also pWO 4 2− sensitive. The pH-sensitivity of GTWIP was explained by a multiphase and multilayer model consisting of a W(3+) reservoir, an electroactive WO 2 +WO 3 ·2H 2 O mixture, a WO 3 ·2H 2 O+H x WO 3 ·2H 2 O mixture and an ion-selective H x WO 3 ·2H 2 O membrane.