Modificação das propriedades estruturais, morfológicas e ópticas do Ag3PO4 e Ag2-2xZnxWO4(0≤ x ≤ 0.25)

• Ano de defesa: 2019
• Autor(a) principal: Santos, Clayane Carvalho dos
• Orientador(a): Silva, Elson Longo da
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de São Carlos; Câmpus São Carlos
• Programa de Pós-Graduação: Programa de Pós-Graduação em Química - PPGQ
• Palavras-chave em Português: Fosfatos; Tunsgtatos; Irradiação; Ópticas
• Palavras-chave em Inglês: Phosphate; Tungstates; Irradiation; Optical
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA INORGANICA
• Link de acesso: https://repositorio.ufscar.br/handle/20.500.14289/12223

Phosphates and tungstates are important compounds and known mainly for their photocatalytic and photoluminescent properties. The present work proposes a study of the structural, morphological and photoluminescent properties of the materials: Ag3PO4 electron beam irradiated and femtosecond laser, and Ag2-2xZnxWO4 (0≤ x ≤ 0.25) modified with different concentrations of Zn+ obtained by the method of co-precipitation. The obtained phases were characterized by X-ray diffraction, Raman scattering spectroscopy, X-ray photoelectron spectroscopy, scanning and transmission electron microscopy, and photoluminescence measurements. The main results investigated for the irradiated Ag3PO4 crystals show that XRD diffraction data show that the patterns for the non-irradiated and similar electron-irradiated samples, while the femtosecond laser-irradiated sample has a higher resolution XRD pattern, low, showing a higher structural disturbance at long range. For the Raman and Rietveld Spectra they show that both [PO4] and [AgO4] are distorted clusters, being the Ag-O bonds of agglomerates [AgO4] more labile than the P-O bonds of clusters [PO4]. In addition, a distinct growth and size mechanism was observed in the production of metallic Ag. For Ag2WO4, the results showed that the increase of Zn concentration in the microcrystals in the α-Ag2WO4 host matrix caused a morphological transformation and a shift of the electronic and optical properties. And regarding the photuluminescent properties of the α-Ag2WO4 and α-Ag2-2xZnxWO4 microcrystals are explained by the effects of distortions and oxygen vacancies (V_O^x) on clusters [WO6] and [AgOy] (y = 2, 4, 6 and 7) respectively causing a redshift.