Get access

On the pH-sensing properties of differently prepared tungsten oxide films

Authors

  • Stefanie Drensler,

    1. Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Linz, Austria
    Search for more papers by this author
  • Sarah Walkner,

    1. Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Linz, Austria
    2. Competence Centre for Electrochemical Surface Technology, Wiener Neustadt, Austria
    Search for more papers by this author
  • Cezarina Cela Mardare,

    1. Christian Doppler Laboratory for Combinatorial Oxide Chemistry at the Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Linz, Austria
    Search for more papers by this author
  • Achim Walter Hassel

    Corresponding author
    1. Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Linz, Austria
    2. Competence Centre for Electrochemical Surface Technology, Wiener Neustadt, Austria
    3. Christian Doppler Laboratory for Combinatorial Oxide Chemistry at the Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, Linz, Austria
    Search for more papers by this author

Abstract

In this paper, different preparation routes and designs for pH sensing metal/metal oxide electrodes are evaluated. Crystallographic changes in the oxide film are responsible for the pH-sensing capability of tungsten oxide. As the present oxide structure is directly limiting the measuring range, as-received tungsten oxide powders were heat treated to produce polymorphs of WO3, in an attempt to extend the measuring range. Furthermore, electrochemical oxide covered electrodes ranging from micro- down to nano-dimensions have been implemented. Optional coating with Nafion, serving as a membrane material, allows shifting the measuring range even to strongly alkaline conditions.

Ancillary