One-step route to a hybrid TiO2/TixW1?xN nanocomposite by in situ selective carbothermal nitridation |
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Authors: | Zo? Schnepp Martin J Hollamby Masahiko Tanaka Yoshitaka Matsushita Yoshio Katsuya Yoshio Sakka |
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Affiliation: | 1.International Center for Young Scientists, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan;2.Synchrotron X-ray Station at SPring-8, NIMS, 1-1-1, Kouto, Sayo-cho, Hyogo 679-5148, Japan;3.SPring-8 Service Co. Ltd, 1-1-1, Kouto, Sayo-cho, Hyogo 679-5148, Japan;4.Advanced Ceramics Group, NIMS, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 Japan |
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Abstract: | Metal oxide/nitride nanocomposites have many existing and potential applications, e.g. in energy conversion or ammonia synthesis. Here, a hybrid oxide/nitride nanocomposite (anatase/TixW1−xN) was synthesized by an ammonia-free sol–gel route. Synchrotron x-ray diffraction, complemented with electron microscopy and thermogravimetric analysis, was used to study the structure, composition and mechanism of formation of the nanocomposite. The nanocomposite contained nanoparticles (<5 nm diameter) of two highly intermixed phases. This was found to arise from controlled nucleation and growth of a single oxide intermediate from the gel precursor, followed by phase separation and in situ selective carbothermal nitridation. Depending on the preparation conditions, the composition varied from anatase/TixW1−xN at low W content to an isostructural mixture of Ti-rich and W-rich TixW1−xN at high W content. In situ selective carbothermal nitridation offers a facile route to the synthesis of nitride-oxide nanocomposites. This conceptually new approach is a significant advance from previous methods, which generally require ammonolysis of a pre-synthesized oxide. |
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Keywords: | 10 1 20 09 |
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