A joint experimental and theoretical study on the electronic structure and photoluminescence properties of Al-2(WO4)(3) powders

Author(s)

Batista, F. M. C. ^[1] ; La Porta, F. A. ^{[2, 3]} ; Gracia, L. ^{[2, 3]} ; Cerdeiras, E. ^[1] ; Mestres, L. ^[1] ; Li, M. Siu ; Batista, N. C. ^{[4, 5]} ; Andres, J. ^[3] ; Longo, E. ^[2] ; Cavalcante, L. S. ^[5]

Affiliation

^[1] Univ Barcelona, Fac Quim, Dept Quim Inorgan, E-08028 Barcelona - Spain

^[2] Univ Estadual Paulista, BR-14801907 Araraquara, SP - Brazil

^[3] UJI, Dept Quim Fis & Analit, Castellon de La Plana 12071 - Spain

^[4] Univ Sao Paulo, IFSC, BR-13560970 Sao Carlos, SP - Brazil

^[5] Univ Estadual Piaui, CCN DQ GERATEC, BR-64002150 Teresina, PI - Brazil

• Document type: Journal article
• Source: Journal of Molecular Structure; v. 1081, p. 381-388, FEB 5 2015.
• Web of Science Citations: 12

Abstract

In this paper, aluminum tungstate Al-2(WO4)(3) powders were synthesized using the co-precipitation method at room temperature and then submitted to heat treatment processes at different temperatures (100, 200, 400, 800, and 1000 degrees C) for 2 h. The structure and morphology of the powders were characterized by means of X-ray diffraction (XRD), Rietveld refinement data, and field emission scanning electron microscopy (FE-SEM) images. Their optical properties were examined with ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy and photoluminescence (PL) measurements. XRD patterns and Rietveld refinement data showed that Al2(W04)3Al(2)(WO4)(3) powders heat treated at 1000 C for 2 h have a orthorhombic structure with a space group (Pnca) without the presence of deleterious phases. FE-SEM images revealed that these powders are formed by the aggregation of several nanoparticles leading to the growth of microparticles with irregular morphologies and an agglomerated nature. UV-vis spectra indicated that optical band gap energy increased from 3.16 to 3.48 eV) as the processing temperature rose, which was in turn associated with a reduction in intermediary energy levels. First-principle calculations were (AU)

• FAPESP's process: 09/50303-4 - Optical and photocatalytic properties of ZnMoO4 and ZnWO4
• Grantee: Laécio Santos Cavalcante
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 12/18597-0 - Investigation of photoluminescent, photocatalytic and bactericide properties of (Ca1-xZnx)WO4 and (Ca1-xAg2x)WO4
• Grantee: Marcio Aurélio Pinheiro Almeida
• Support Opportunities: Scholarships in Brazil - Post-Doctoral