Structural refinement, morphology and photocatalytic properties of -(Ag2-2xZnx)MoO4 microcrystals synthesized by the sonochemical method

Autor(es)

Coimbra, D. W. R. ^[1] ; Cunha, F. S. ^[2] ; Sczancoski, J. C. ^[3] ; de Carvalho, J. F. S. ^[1] ; de Macedo, F. R. C. ^[1] ; Cavalcante, L. S. ^{[2, 1]}

Afiliação do(s) autor(es)

^[1] Univ Fed Piaui, PPGCM, BR-64049550 Teresina, PI - Brazil

^[2] Univ Estadual Piaui, PPGQ GERATEC, Rua Joao Cabral 2231, POB 381, BR-64002150 Teresina, PI - Brazil

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

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS; v. 30, n. 2, p. 1322-1344, JAN 2019.
• Citações Web of Science: 0

Resumo

In this paper, we report on structure, morphology, and photocatalytic (PC) properties of silver zinc molybdate {[}-(Ag2-2xZnx)MoO4] microcrystals (x=0; 0.01; 0.02 and 0.04) synthesized by the sonochemical method at 30 degrees C for 3h. These microcrystals were structurally characterized by X-ray diffraction (XRD) patterns, Rietveld refinement data, micro-Raman and Fourier transform-infrared (FT-IR) spectroscopies. The morphological aspects (shape andaverage crystal size) and the chemical composition of-Ag2MoO4 microcrystalswere performed by field emission-scanning electron microscope (FE-SEM) and energy dispersive X-ray spectrometry (EDX), respectively. The optical behavior was monitoredby ultraviolet-visible (UV-Vis) spectroscopy at room temperature. Weinvestigate the PC properties for degradation of Remazol Brilliant Violet 5R (RBV5R) anionic dye byusing four UV-C lamps(18W each). XRD patterns, Rietveld refinement data, micro-Raman and FT-IR spectra indicate that all -(Ag2-2xZnx)MoO4 microcrystals (x=0; 0.01; 0.02 and 0.04) have a spinel-type cubic structure and space group >. Rietveld refinement results indicatedthat the Ag atoms werereplaced by Zn atoms at A-site in Wyckoff positions. The micro-Raman spectra exhibited the presence of four Raman-active vibrational modes, while FT-IR spectrarevealed only one infrared-active vibrational mode. FE-SEM images showed that the replacement of Ag atoms by those of Zn changed the growth process. Particularly, the increase of Zn content into the lattice changed the crystal shape from irregular sphere, cube, and octahedrons to irregular octahedrons and rhombic dodecahedron microcrystals, resulting inthe appearance of pores on the crystal surfaces. Moreover, FE-SEM images indicatedthat the growth of these crystals is governed by aggregation and Ostwald ripening. Finally, we demonstrate for the first time that PC activity can be enhanced up to 80min by approximately 97.28% for the degradation of RBV5R dye byusing -(Ag1.96Zn0.02)MoO4 microcrystals as photocatalyst and ammonium oxalate ashole scavenger. (AU)

• Processo FAPESP: 14/26982-7 - Centro de Desenvolvimento de Materiais Funcionais
• Beneficiário: Elson Longo da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Reserva Técnica para Infraestrutura Institucional de Pesquisa