Silver-controlled evolution of morphological, structural, and optical properties of three-dimensional hierarchical WO3 structures synthesized from hydrothermal method
| Autor: | Adenilson J. Chiquito, F. M. Pontes, Valmor Roberto Mastelaro, L.F. Lopes, Elson Longo, Y.N. Colmenares, Silvio Rainho Teixeira, L.O. Garcia, D. S. L. Pontes, D. Padovani |
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| Přispěvatelé: | Universidade Estadual Paulista (Unesp), Universidade Federal de São Carlos (UFSCar), Universidade de São Paulo (USP) |
| Rok vydání: | 2018 |
| Předmět: |
Thermogravimetric analysis
Silver Materials science Scanning electron microscope NANOPARTÍCULAS 02 engineering and technology 010402 general chemistry Microcrystals 01 natural sciences Hydrothermal circulation symbols.namesake X-ray photoelectron spectroscopy Materials Chemistry Fourier transform infrared spectroscopy Spectroscopy Mechanical Engineering Metals and Alloys Tungsten oxide 021001 nanoscience & nanotechnology Hydrothermal 0104 chemical sciences Crystallography Mechanics of Materials symbols Nanoparticles Orthorhombic crystal system 0210 nano-technology Raman spectroscopy |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP Scopus Repositório Institucional da UNESP Universidade Estadual Paulista (UNESP) instacron:UNESP |
| Popis: | Made available in DSpace on 2018-12-11T16:50:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-03-05 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Hierarchical structures of self-assembled three-dimensional (3D) WO3–Ag were synthesized via hydrothermal growth using precursor solutions of peroxopolytungstic acid with different amounts of Ag. The as-grown samples were analyzed by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible spectroscopy, and X-ray photoelectron spectroscopy. The XRD and Raman studies showed that as the amount of Ag was varied from 0 to 10 wt% in the hydrothermal growth solution, the crystal phase gradually changed from orthorhombic WO3·0.33H2O to hexagonal WO3. The FTIR and TGA studies revealed different hydration levels, supporting the XRD and Raman results. By controlling the amount of Ag in the precursor solution, platelet-like building blocks and hexagonal building blocks were obtained, highlighting the role of Ag in the hydrothermal growth of 3D WO3·0.33H2O and WO3 microcrystals. In addition, high-magnification FESEM images showed that the Ag nanoparticles were anchored on the surface of the 3D hierarchical WO3–Ag structures, and the UV–vis measurements demonstrated that the 3D hierarchical structures gradually absorbed more light when the Ag content was increased. Moreover, the band-gap energy decreased when the Ag content was increased from 0 wt% (Eg = 2.65 eV) to 10 wt% (Eg = 2.26 eV). These experimental results demonstrate that the amount of Ag played a crucial role in determining the building blocks' morphology, and the hydration level, optical properties, and crystal phase of the WO3·nH2O microcrystals. Department of Chemistry Universidade Estadual Paulista - Unesp, P.O. Box 473 NanO LaB Department of Physics Universidade Federal de São Carlos, Via Washington Luiz, Km 235, P.O. Box 676 Departamento of Physics Universidade Estadual Paulista Faculdade de Ciências e Tecnologia - FCT, Rua Roberto Simonsen, 305 Physics Institute of São Carlos (IFSC) University of São Paulo LIEC CDMF- Department of Chemistry Universidade Federal de São Carlos, Via Washington Luiz, Km 235, P.O. Box 676 Department of Chemistry Universidade Estadual Paulista - Unesp, P.O. Box 473 Departamento of Physics Universidade Estadual Paulista Faculdade de Ciências e Tecnologia - FCT, Rua Roberto Simonsen, 305 FAPESP: 11/20536-7 FAPESP: 12/14106-2 FAPESP: 13/07296-2 CNPq: 470147/2012-1 |
| Databáze: | OpenAIRE |
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