Hydrothermal deposition of tungsten oxide monohydrate films and room temperature gas sensing performance

• Published in: Journal of alloys and compounds 2016-01, Vol.656, p.326-331
• Main Authors: Han, Liuyuan, Chen, Changlong, Wei, Yuling, Shao, Baiqi, Mu, Xiaohui, Liu, Qinglong, Zhu, Peihua
• Format: Article
• Language: English
• Subjects: Alloys; Deposition; Gas sensor; Gas sensors; Glass; Hydrothermal deposition; Locking; Nitrogen dioxide; Nuclei; Tungsten oxide monohydrate; Tungsten oxides
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2015.08.261

Tungsten oxide monohydrate (WO3·H2O) films on glass substrates were prepared by hydrothermal deposition without using any additives. The resulting crystals were single crystalline and possessed microplate-like shape with preferred growth in the two dimensions perpendicular to [010] direction. Many of the WO3·H2O microplates were found to embed into each other, forming interesting interlocking configuration. The initial distance among the nuclei was considered to play decisive role in the formation of the interlocking structure. Gas sensing tests showed that at room temperature the WO3·H2O films could detect 20 ppm of NO2 gas. The room temperature-based measurements guaranteed that the collected data really came from the WO3·H2O itself rather than from the dehydrated product that would be easily formed if elevated measurement temperature was applied. Such an additive-free method to prepare WO3·H2O films is promising to provide good candidate materials for applications like gas sensing, solar energy conversion, and so on. [Display omitted] •WO3·H2O microplate films were hydrothermally deposited without using any additives.•The microplates possessed decahedron morphology and inter-locking structure.•The initial distance of the nuclei was key for the formation of the inter-locking structure.•Room temperature NO2 gas sensing performance based on WO3·H2O was reported for the first time.