Size-induced amorphous structure in tungsten oxide nanoparticles

Abstract

The properties of functional materials are intrinsically linked to their atomic structure. When going to the nanoscale, size-induced structural changes in atomic structure often occur, however these are rarely well-understood. Here, we systematically investigate the atomic structure of tungsten oxide nanoparticles as a function of the nanoparticle size and observe drastic changes when the particles are smaller than 5 nm, where the particles are amorphous. The tungsten oxide nanoparticles are synthesized by thermal decomposition of ammonium metatungstate hydrate in oleylamine and by varying the ammonium metatungstate hydrate concentration, the nanoparticle size, shape and structure can be controlled. At low concentrations, nanoparticles with a diameter of 2-4 nm form and adopt an amorphous structure that locally resembles the structure of polyoxometalate clusters. When the concentration is increased the nanoparticles become elongated and form nanocrystalline rods up to 50 nm in length. The study thus reveals a size-dependent amorphous structure when going to the nanoscale and provides further knowledge on how metal oxide crystal structures change at extreme length scales.

• author: Juelsholt, Mikkel ; Anker, Andy S. ; Christiansen, Troels Lindahl ; Jørgensen, Mads Ry Vogel ; Kantor, Innokenty ; Sørensen, Daniel Risskov and Jensen, Kirsten M.Ø.
• organization: MAX IV Laboratory
• publishing date: 2021-12-21
• type: Contribution to journal
• publication status: published
• subject: Inorganic Chemistry
• in: Nanoscale
• volume: 13
• issue: 47
• pages: 13 pages
• publisher: Royal Society of Chemistry
• external identifiers: pmid:34846442; scopus:85121434573
• ISSN: 2040-3364
• DOI: 10.1039/d1nr05991b
• language: English
• LU publication?: yes
• additional info: Funding Information: We are grateful to the Villum Foundation for financial support through a Villum Young Investigator grant (VKR00015416). We acknowledge the Carlsberg Foundation for financial support through grants CF14-0652 and CF17-0976. Funding from the Danish Ministry of Higher Education and Science through the SMART Lighthouse is gratefully acknowledged. We thank DANSCATT (supported by the Danish Agency for Science and Higher Education) for support. We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out at P02.1 and we would like to thank Martin Etter for assistance in using the beamline. We acknowledge MAX IV Laboratory for time on Beamline DanMAX under Proposal 20200731. Research conducted at MAX IV is supported by the Swedish Research Council under contract 2018-07152, the Swedish Governmental Agency for Innovation Systems under contract 2018-04969, and Formas under contract 2019-02496. DanMAX is funded by the NUFI grant no. 4059-00009B. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility, operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Part of this work was performed in part at DTU Danchip/Cen, the National Center for Micro-and Nanofabrication at the Technical University of Denmark. This work benefited from the use of the SasView application, originally developed under NSF award DMR-0520547. SasView contains code developed with funding from the European Union’s Horizon 2020 research and innovation programme under the SINE2020 project, grant agreement No. 654000. Publisher Copyright: © The Royal Society of Chemistry.
• id: 163c44e6-d77c-49a8-abed-b4e1dd273690
• date added to LUP: 2022-01-11 18:10:40
• date last changed: 2024-04-20 19:58:49