Review on the Versatility of Tungsten Oxide Coatings

Tungsten oxide is a versatile material with many advantages such as large availability and low fabrications costs. Additionally, it is suitable to be produced in the form of thin films or coatings, which makes it very attractive for many applications. In this Feature Article, the material properties such as crystallography, chemical stability, and semiconducting properties are presented, followed by examples of coating technologies. Furthermore, the relation between its structure and some of the very important applications fields such as electro- and photochromism, as well as pH sensing are analyzed in detail. Its auspicious semiconducting properties make it attractive to be used as photo(electro)catalyst, therefore applications of thin films based on WO3 are emphasized such as photoanodes for water splitting, in healthcare as antimicrobial material and for degradation of pollutants or for CO2 reduction. The article is concluded by a short overview of the current status of research employing tungsten oxide.