title: One-step route to a hybrid TiO2/TixW1-xN nanocomposite byin situselective carbothermal nitridation.
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 andin situselective 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 situselective 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.
authors.affiliation: International Center for Young Scientists, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
authors.forename: Zoë
authors.initials: Z
authors.lastname: Schnepp
authors.affiliation: International Center for Young Scientists, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Hollamby
authors.affiliation: Synchrotron X-ray Station at SPring-8, NIMS, 1-1-1, Kouto, Sayo-cho, Hyogo 679-5148, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Synchrotron X-ray Station at SPring-8, NIMS, 1-1-1, Kouto, Sayo-cho, Hyogo 679-5148, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Matsushita
authors.affiliation: SPring-8 Service Co. Ltd, 1-1-1, Kouto, Sayo-cho, Hyogo 679-5148, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Katsuya
authors.affiliation: Advanced Ceramics Group, NIMS, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Sakka
keywords: 10.1; 20.09; Ti–W–N; carbothermal nitridation; oxide/nitride nanocomposite; sol–gel; synchrotron XRD