Effect of the pH pre-adjustment on the formation of In(2)W(3)O(12 )and In6WO12 powders: Cluster coordination and optical band gap

Author(s)

de Paiva, Rafael Texeira ^[1] ; Nogueira, Icamira Costa ^[2] ; Sczancoski, Julio Cesar ^[3] ; Lemos, Pablo Santana ^[3] ; Elias Matos, Jose Milton ^[1] ; Santos, Reginaldo Silva ^[4] ; Longo, Elson ^[5] ; Cavalcante, Laecio Santos ^{[1, 4]}

Affiliation

^[1] Univ Fed Piaui, Programa Posgrad Ciencia Mat PPCM, BR-64049550 Teresina, PI - Brazil

^[2] ICE Univ Fed Amazonas, Ave Rodrigo Otavio Japiim, POB 670, BR-69077000 Manaus, Amazonas - Brazil

^[3] Univ Fed Sao Carlos, DQ UFSCar, POB 676, BR-13565905 Sao Carlos, SP - Brazil

^[4] Univ Estadual Piaui, PPGQ GERATEC, Joao Cabral 2231, POB 381, BR-64002150 Teresina, PI - Brazil

^[5] Univ Estadual Paulista, Dept Quim Fis, BR-14800060 Araraquara, SP - Brazil

• Document type: Journal article
• Source: BOLETIN DE LA SOCIEDAD ESPANOLA DE CERAMICA Y VIDRIO; v. 59, n. 1, p. 2-14, JAN-FEB 2020.
• Web of Science Citations: 0

Abstract

In this communication, diindium tristungstate (In2W3O12) and hexaindium tungstate (In6WO12) powders were synthesized by the co-precipitation method at different pH values and heat treatment at 1073 K for 2 h. X-ray diffraction patterns and Rietveld refinements were employed to analyze the long-range structural ordering as well as quantify the presence crystallographic phases, respectively. All powders obtained in pH ranging from 2 to 3.5 exhibited a mixture of In2W3O12 and gamma-tungsten oxide (gamma-WO3) phases. When prepared at pH close to 4, the powders presented both In2W3O12 and In6WO12 phases. All these crystalline structures were simulated in a three-dimensional visualization program by adopting the Rietveld refinements analysis as input data. The ultraviolet-visible spectra were employed to estimate the optical band gap energy of all powders for the first time. (C) 2019 Published by Elsevier Espana, S.L.U. on behalf of SECV. (AU)

• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 12/14004-5 - Investigation of the photoluminescence and photocatalytic properties of pure and Mn, Cu, and Zn-doped BaWO4 and BaMoO4 powders
• Grantee: Júlio César Sczancoski
• Support Opportunities: Scholarships in Brazil - Post-Doctoral