Dissolution kinetics of WO3 in acidic solutions


Anik M. , Cansizoglu T.

JOURNAL OF APPLIED ELECTROCHEMISTRY, cilt.36, sa.5, ss.603-608, 2006 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 36 Konu: 5
  • Basım Tarihi: 2006
  • Doi Numarası: 10.1007/s10800-006-9113-3
  • Dergi Adı: JOURNAL OF APPLIED ELECTROCHEMISTRY
  • Sayfa Sayıları: ss.603-608

Özet

Potentiostatic polarization and rotating disk electrode techniques were used to obtain the rate constant for the dissolution of electrochemically-formed (at 1 V) WO3 on tungsten (W) in acidic solutions. The corresponding rate constant for the chemical dissolution of WO3(s) powder was found by measuring the dissolved tungsten concentration as a function of time and pH. The chemical dissolution experiments supported the view that the rate-determining step in the anodic reaction of W in acidic solution is the chemical dissolution of WO3(s) formed on the metal surface. Zeta potential measurements gave the isoelectric point (iep) of the WO3(s) powder as pH 1.5, a value that was somewhat smaller than the point of zero charge (pzc) of WO3(s) formed on W metal (pH 2.5). This difference was attributed to the highly hydrated nature of the oxide film formed on W metal in aqueous systems.