Synthesis of tungsten oxide nanoparticles using a hydrothermal method at ambient pressure

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Tungsten oxide (WO3) nanostructures receive sustained interest for a wide variety of applications, and especially for its usage as a photocatalyst. It is therefore important to find suitable methods allowing for its easy and inexpensive large scale production. Tungstite (WO3 center dot H2O) nanoparticles were synthesized using a simple and inexpensive low temperature and low pressure hydrothermal (HT) method. The precursor solution used for the HT process was prepared by adding hydrochloric acid to diluted sodium tungstate solutions (Na2WO4 center dot 2H(2)O) at temperatures below 5 degrees C and then dissolved using oxalic acid. This HT process yielded tungstite (WO3 center dot H2O) nanoparticles with the orthorhombic structure. A heat treatment at temperatures at or above 300 degrees C resulted in a phase transformation to monoclinic WO3, while preserving the nanoparticles morphology. The production of WO3 nanoparticles using this method is therefore a three step process: protonation of tungstate ions, crystallization of tungstite, and phase transformation to WO3. Furthermore, this process can be tailored. For example, we show that WO3 can be doped with cesium and that nanorods can also be obtained. The products were characterized using powder x-ray diffraction, transmission electron microscopy (including electron energy-loss spectroscopy and electron diffraction), and x-ray photoelectron spectroscopy.
Original languageEnglish
JournalJournal of Materials Research
Volume29
Issue number13
Pages (from-to)1424-1430
ISSN0884-2914
DOIs
Publication statusPublished - 2014
CitationsWeb of Science® Times Cited: No match on DOI

    Research areas

  • MATERIALS, ENERGY-LOSS SPECTROSCOPY, OXYGEN K-EDGE, VISIBLE-LIGHT, HIERARCHICAL NANOSTRUCTURES, ELECTRONIC-STRUCTURE, WO3, GROWTH, FILMS, OXIDATION, NANOWIRES

ID: 99728113