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.

Single crystalline tungsten nanowires were prepared from directionally solidified NiAl‐W alloys by a chemical release from the resulting binary phase material. Electron back scatter diffraction (EBSD) proves that they are single crystals having identical crystallographic orientation. Mechanical investigations such as bending tests, lateral force measurements, and mechanical resonance measurements were performed on 100–300 nm diameter wires. The wires could be either directly employed using micro tweezers, as a singly clamped nanowire or in a doubly clamped nanobridge. The mechanical tests exhibit a surprisingly high flexibility for such a brittle material resulting from the small dimensions. Force displacement measurements on singly clamped W nanowires by an AFM measurement allowed the determination of a Young′s modulus of 332 GPa very close to the bulk value of 355 GPa. Doubly clamped W nanowires were employed as resonant oscillating nanowires in a magnetomotively driven resonator running at 117 kHz. The Young′s modulus determined from this setup was found to be higher 450 GPa which is likely to be an artefact resulting from the shift of the resonance frequency by an additional mass loading.

Microbial electrosynthetic cells containing Methylobacterium extorquens were studied for the reduction of CO₂ to formate by direct electron injection and redox mediator‐assisted approaches, with CO₂ as the sole carbon source. The formation of a biofilm on a carbon felt (CF) electrode was achieved while applying a constant potential of −0.75 V versus Ag/AgCl under CO₂‐saturated conditions. During the biofilm growth period, continuous H₂ evolution was observed. The long‐term performance for CO₂ reduction of the biofilm with and without neutral red as a redox mediator was studied by an applied potential of −0.75 V versus Ag/AgCl. The neutral red was introduced into the systems in two different ways: homogeneous (dissolved in solution) and heterogeneous (electropolymerized onto the working electrode). The heterogeneous approach was investigated in the microbial system, for the first time, where the CF working electrode was coated with poly(neutral red) by the oxidative electropolymerization thereof. The formation of poly(neutral red) was characterized by spectroscopic techniques. During long‐term electrolysis up to 17 weeks, the formation of formate was observed continuously with an average Faradaic efficiency of 4 %. With the contribution of neutral red, higher formate accumulation was observed. Moreover, the microbial electrosynthetic cell was characterized by means of electrochemical impedance spectroscopy to obtain more information on the CO₂ reduction mechanism.