Open AccessTAILORING THE STRUCTURE AND MORPHOLOGY OF WO3 NANOSTRUCTURES BY HYDROTHERMAL METHOD
Author(s) -
Luu Thi Lan Anh
Publication year - 2018
Publication title -
vietnam journal of science and technology/science and technology
Language(s) - English
Resource type - Journals
eISSN - 2815-5874
pISSN - 2525-2518
DOI - 10.15625/2525-2518/56/1a/12513
Subject(s) - nanorod , orthorhombic crystal system , hydrothermal circulation , raman spectroscopy , monoclinic crystal system , materials science , nanoparticle , nanostructure , tungsten , nanotechnology , hydrothermal synthesis , crystal structure , chemical engineering , transmission electron microscopy , morphology (biology) , crystallography , chemistry , optics , physics , biology , engineering , metallurgy , genetics
Tungsten oxide nanostructures were synthesized by hydrothermal and acid precipitation (hydrothermal at room temperature) methods without using any supporting agent or structure-directing reactant. The morphology and crystalline structure of nanostructures strongly depended on pH of the precursor solution and synthesis method. With pH = -1.0, using acid precipitation method, orthorhombic nanoplate was observed. Using hydrothermal method, with the pH = - 1.0, we obtained directly stable monoclinic nanoparticle WO3. With pH = 1.1, the mixing of nanoparticle and nanorod with the hexagonal frame was acquired. When pH reaches to 1.7, only bundle of hexagonal nanorods was observed. To characterize the morphology and structure of tungsten nanostructures, we used Field Emission Scanning Electron Microscopy, X-ray diffraction, and micro Raman spectroscopy. The micro Raman spectroscopy was used to support the X-ray diffraction analysis. These results imply that adjusting pH is an efficient and promising method to manipulate both morphology and crystal structure of WO3 nanostructure for selective applications.