Banca de DEFESA: OLÍMPIO JOSÉ DA SILVA JÚNIOR

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : OLÍMPIO JOSÉ DA SILVA JÚNIOR
DATA : 20/02/2019
HORA: 15:00
LOCAL: Videoteca da Biblioteca Central Zila Mamede
TÍTULO:

COORDINATION POLYMERS AND THEIR DERIVED OXIDES: FROM THE PREPARATION TO APPLICATION IN THE DECOLORIZATION OF WATER CONTAMINATED WITH ORGANICS DYES

PALAVRAS-CHAVES:

Metal-Organic Frameworks; Ca-MOF; Cu-MOF; CuO; Methylene blue; Adsorption; Degradation; discoloration

PÁGINAS: 110
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Inorgânica
ESPECIALIDADE: Compostos Organo-Metálicos
RESUMO:

Coordination polymers (CP) are a new class of hybrid materials consisting of metal species or clusters connected by organic linkers and forming structures along one, two or three dimensions. In this research, we propose the use of CPs and their derived oxides in the discoloration of water contaminated with organic dyes. Three Cu²⁺ coordination polymers were prepared by an electrochemical method using the following linkers: 1,3-H₂BDC, 1,4-H₂BDC, and 5-NH₂-H₂BDC. The samples obtained were calcined in air at 923 K yielding porous CuO. The synthesis of Ca-MOFs was performed using a sonochemical method. The main synthetic parameters were studied, and the factorial planning was employed to reduce the total number of samples produced. All the prepared samples were characterized by X-ray powder diffraction (PXRD), Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance (ATR-FTIR), Thermal Analysis (TGA-DTA) and Scanning Electron Microscopy (SEM). The results confirmed both the crystallization of the Cu²⁺ coordination polymers and the formation of the copper oxide after the heat treatment. The porous CuO was tested for the catalytic degradation of methylene blue in the presence of H₂O₂, and the effect of reaction parameters such as catalyst mass and H₂O₂ volume were studied. The optimum reaction conditions were established, with discoloration reaching about 94 and 100% at 308 and 311 K, respectively, after only 120 minutes of reaction. The Ca-MOFs samples were applied in the adsorption of the methylene blue dye at natural pH, obtaining maximum adsorption of 60.241 μmol.g^-1 and high efficiency in the reuse, reaching 97% of the initial adsorption capacity in the second reuse cycle. The results suggest that the presence of the [Ca(BDC)(DMF)(H₂O)] phase does not increase the adsorption capacity when compared to the other crystalline phase obtained, [Ca(BDC)(H₂O)₃]_n. Both materials have been shown to be promising in the discoloration of contaminated water.

MEMBROS DA BANCA:
Presidente - 1754300 - BRAULIO SILVA BARROS
Externo à Instituição - CLEONILSON MAFRA BARBOSA - IFRN
Interno - 1959889 - DAVI SERRADELLA VIEIRA
Externa à Instituição - ELANIA MARIA FERNANDES SILVA - UFRN
Externa à Instituição - JOANNA ELZBIETA KULESZA - UFPE