Synthesis and characterization of metastable beta-Ag2WO4: an experimental and theoretical approach

Autor(es)

Lemos, Pablo S. ^[1] ; Altomare, A. ^[2] ; Gouveia, A. F. ^[1] ; Nogueira, I. C. ^[3] ; Gracia, L. ^{[4, 5]} ; Llusar, R. ^[4] ; Andres, J. ^[4] ; Longo, E. ^{[5, 1]} ; Cavalcante, Laecio S. ^[6]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, DQ, BR-13565905 Sao Paulo - Brazil

^[2] CNR, Inst Crystallog, I-70126 Bari - Italy

^[3] PPG Engn Mat, Inst Fed Maranhao, BR-65030005 Sao Luis, MA - Brazil

^[4] Univ Jaume 1, Dept Analyt & Phys Chem, Castellon de La Plana 12071 - Spain

^[5] Univ Estadual Paulista, CDMF, BR-14801907 Araraquara, SP - Brazil

^[6] Univ Estadual Piaui, GERATEC, DQ, BR-64002150 Teresina, PI - Brazil

• Tipo de documento: Artigo Científico
• Fonte: DALTON TRANSACTIONS; v. 45, n. 3, p. 1185-1191, 2016.
• Citações Web of Science: 8

Resumo

Metastable silver tungstate (beta-Ag2WO4) has attracted much attention lately because of its many potential applications. However, the synthesis of metastable phases of inorganic compounds is challenging because of the ease of transformation to the stable phase. We have overcome this challenge and have successfully synthesized beta-Ag2WO4 microcrystals using a dropwise precipitation (DP) method in aqueous media at low temperature. The microcrystals were characterized by X-ray diffraction (XRD), including powder X-ray diffraction structural determination, field-emission scanning electron microscopy (FE-SEM), and micro-Raman/ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy. To complement the experimental data, we present first-principles quantum-mechanical density functional theory (DFT) calculations. Using XRD data, Raman/UV-vis data, and the determined optical band gap, together with geometric optimization calculations, we confirmed the structure of this compound. beta-Ag2WO4 has a hexagonal structure with a P6(3)/m space group. The building blocks of the lattice comprise two types of W-O clusters, {[}WO4] and {[}WO5], coordinated to four and five O atoms, respectively, and two types of Ag-O clusters, {[}AgO6], and {[}AgO5], linked to six and five O atoms, respectively. This type of fundamental study, combining multiple experimental methods and first-principles calculations, helps to obtain a basic understanding of the local structure and bonding in the material. (AU)

• Processo FAPESP: 13/26671-9 - Estudo teórico-experimental de semicondutores multifuncionais
• Beneficiário: Amanda Fernandes Gouveia
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais
• Beneficiário: Elson Longo da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs