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Your search keyword '"Luís F. da Silva"' showing total 2 results
Start Over Author "Luís F. da Silva" Journal journal of alloys and compounds
2 results on '"Luís F. da Silva"'

1. Improving the ozone gas-sensing properties of CuWO4 nanoparticles

Author

Ariadne C. Catto, Érica L.S. Souza, Juan Andrés, Luís F. da Silva, Waldir Avansi, Khalifa Aguir, Elson Longo, Laécio S. Cavalcante, Tomas Fiorido, Generalitat Valenciana, Ministerio de Economia y Competitividad, and Programa de Cooperación Cientifíca con Iberoamerica (Brazil), Ministerio de Educación, Universidade Estadual Paulista (Unesp), Aix Marseille Univ, Univ Estadual Piaui, Universidade Federal de São Carlos (UFSCar), and Jaume I Univ

Subjects
Diffraction, Materials science, Ozone, Annealing (metallurgy), Nanoparticle, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, law.invention, chemistry.chemical_compound, sonochemical, Electrical resistance and conductance, law, Materials Chemistry, surface, Crystallization, chemiresistor, Spectroscopy, Chemiresistor, Mechanical Engineering, Metals and Alloys, 021001 nanoscience & nanotechnology, 0104 chemical sciences, ozone, Chemical engineering, chemistry, Mechanics of Materials, CuWO4, 0210 nano-technology
Abstract

Made available in DSpace on 2018-11-29T12:10:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-06-05 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Brazilian Nanotechnology National Laboratory Brazilian Laboratory of Synchrotron Radiation (LNLS) Generalitat Valenciana, Ministerio de Economia y Competitividad Programa de Cooperacion Cientifica con Iberoamerica (Brazil), Ministerio de Educacion This paper consists of an experimental investigation on the effects of annealing temperature on the structural, surface and ozone gas-sensing properties of CuWO4 nanoparticles prepared via a sono-chemical route. X-ray diffraction patterns and X-ray absorption near-edge structure spectroscopy revealed that both long-and short-order structures increase with the annealing temperature. Electrical resistance measurements indicated that CuWO4 samples were sensitive in the range of 15-1400 ppb, exhibiting a good reversibility and repeatability. The enhancement of the ozone gas-sensing properties was attributed to the reduction of hydroxyl species and the improvement of the crystallization degree. This study provides a versatile strategy for obtaining CuWO4 nanoparticles for practical applications as an ozone gas sensor. (C) 2018 Elsevier B.V. All rights reserved. Sao Paulo State Univ, Inst Chem, POB 355, BR-14801907 Araraquara, SP, Brazil Aix Marseille Univ, CNRS UMR 7334 IM2NP, FS St Jerome S152, F-13397 Marseille, France Univ Estadual Piaui, PPGQ CCN, POB 381, BR-64002150 Teresina, PI, Brazil Univ Fed Sao Carlos, Dept Phys, Lab Nanostruct Multifunct Mat, BR-13565905 Sao Carlos, SP, Brazil Jaume I Univ, Dept Chem & Phys, Castellon De La Plana, Spain Sao Paulo State Univ, Inst Chem, POB 355, BR-14801907 Araraquara, SP, Brazil FAPESP: 2013/07296-2 FAPESP: 2017/10313-7 FAPESP: 2017/12437-5 CNPq: 310863/ 2014-7 CNPq: 434266/2016-7 Brazilian Nanotechnology National Laboratory: LMF-18580 Brazilian Laboratory of Synchrotron Radiation (LNLS): D04B-XAFS111883

Published
2018
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2. Cerium molybdate nanocrystals: Microstructural, optical and gas-sensing properties

Author

Ariadne C. Catto, Ricardo L. Tranquilin, Fabiana V. Motta, F. K. F. Oliveira, Luís F. da Silva, Mauricio R. D. Bomio, Elson Longo, and A.A.G. Santiago

Subjects
Materials science, Photoluminescence, Scanning electron microscope, chemistry.chemical_element, 02 engineering and technology, Molybdate, 010402 general chemistry, 01 natural sciences, Microwave-assisted hydrothermal, Tetragonal crystal system, symbols.namesake, chemistry.chemical_compound, Ozone, Materials Chemistry, Microstructure, Mechanical Engineering, Metals and Alloys, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Cerium, Cerium molybdate, Chemical engineering, Nanocrystal, chemistry, Mechanics of Materials, symbols, Gas sensor, 0210 nano-technology, Raman spectroscopy
Abstract

Metal molybdate compounds have attracted considerable attention due to their technological applications. Herein, we demonstrate the controllable synthesis of cerium molybdate (Ce2(MoO4)3) nanocrystals via the co-precipitation method followed by microwave-assisted hydrothermal (MAH) treatment at 150 C during different times (15, 30 and 60 min). The effect of MAH treatment time on the microstructural, optical, and ozone gas-sensing properties of these nanocrystals was investigated. X-ray diffraction (XRD) and Raman spectroscopy measurements revealed that the samples presented a single-crystalline phase with scheelite-type tetragonal structure. Field emission gun scanning electron microscopy (FEG-SEM) images showed that the MAH conditions favored changes in the Ce2(MoO4)3 nano crystal morphology. Photoluminescence (PL) measurements indicated a significant enhancement of PL emission with MAH time, suggesting an increase in the intrinsic defects formed during the MAH treatment. The gas-sensing performance of cerium molybdate nanocrystals towards sub-ppm ozone levels was also investigated. The experiments revealed complete recovery and good repeatability as well as good sensor response, which was improved in the sample synthesized at longer MAH time

Published
2021
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