Banca de QUALIFICAÇÃO: EDUARDO DE OLIVEIRA GOMES

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : EDUARDO DE OLIVEIRA GOMES
DATA : 05/09/2017
HORA: 09:30
LOCAL: Auditório do Departamento de Estatística
TÍTULO:

Study of the photoluminescent and photocatalytic properties of BaMoO4 and its synthesis by microwave assisted hydrothermal method

PALAVRAS-CHAVES:

Photocatalysis; Hydrothermal Microwave; Semiconductors; Photoluminescence; Chemical synthesis.

PÁGINAS: 64
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

BaMoO4 particles were synthesized by the co-precipitation method at room temperature followed by the microwave assisted hydrothermal method at different times (1, 2, 4 and 8 minutes) with and without surfactants. The crystals formed acquired geometric morphologies similar to octahedra, and were structurally characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. The optical properties were investigated by photoluminescence (PL) and ultraviolet-visible (UV-vis). The X-ray diffractograms shown that the octahedra have a tetragonal crystalline structural classification of the scheelite type and without the presence of second phases. The FTIR showed active modes in the infrared region F2 (ⱱ3) and F2 (ⱱ4) which are respectively for BaMoO4 assigned to the antisymmetric stretching and bending mode modes, where F2 (ⱱ3) is related to antisymmetric Mo-O vibration within the Group [MoO4]2-. It also indicated the characteristic band of BaMoO4 in the range of 900-800 cm-1. Optical data from UV-Vis revealed that the values of gap energy (Egap) were around 4.27 and 4.49 eV. Field emission electron microscopy (FEG-MEV) was used to observe the several morphologies and it was proposed the mechanism of particle growth and formation. The photocatalytic properties of BaMoO4 particles were investigated through photocatalysis test by dye degradation.

MEMBROS DA BANCA:
Interno - 1802888 - FABIANA VILLELA DA MOTTA
Externo à Instituição - JUAN MANUEL ANDRÉS BORT - UJI
Presidente - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE