Banca de QUALIFICAÇÃO: VITOR MANOEL SILVA FERNANDES DE SOUZA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : VITOR MANOEL SILVA FERNANDES DE SOUZA
DATE: 13/12/2024
TIME: 14:00
LOCAL: online
TITLE:

STUDY OF THE SYNTHESIS AND CHARACTERIZATION OF COPPER NIOBATE VIA SOL-GEL METHOD FROM THE PREPARATION OF NIOBIUM PRECURSOR

KEY WORDS:

copper niobate; sol-gel; synthesis; characterization.

PAGES: 85
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Cerâmicos
SUMMARY:

This study focuses on investigating the synthesis of Copper Niobate (CuNb₂O₆) using the protein-based Sol-Gel method, a wet chemical route that remains relatively unexplored for obtaining this material. This approach stands out as a sustainable alternative, starting from the preparation of the Ammonium Niobium Oxalate precursor. CuNb₂O₆ has garnered scientific interest due to its properties and technological applications, such as in solar cells, microwave devices, and infrared lasers. Given the growing need for simpler and cost-effective methodologies to produce this nanomaterial, precursors of Ammonium and Niobium Oxalates, obtained through fusion and complexation processes, along with commercial Copper Nitrate, were utilized. Both precursors are highly water-soluble, and gelatin was used as a chelating and polymerizing agent. The resulting gels underwent thermal treatments, being calcined in a muffle furnace at 700 °C, 800 °C, and 900 °C for 3 hours, with a heating rate of 5 °C/min. The samples were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and Thermogravimetric Analysis (TGA) for Niobium Oxalate. The results revealed that at 800 °C, the product fully formed in the monoclinic phase, while at 900 °C, CuNb₂O₆ completely crystallized in the orthorhombic phase, demonstrating the effectiveness of the produced precursor for use in chemical reactions. The applied methodology reduced the material's formation temperature for both crystalline structures. The obtained samples showed high purity, good dispersion, absence of contamination, and characteristic morphologies consistent with literature data.

COMMITTEE MEMBERS:
Presidente - ***.121.804-** - UILAME UMBELINO GOMES - UFRN
Interna - 3352345 - MARIA JOSE SANTOS LIMA
Interna - 1308577 - SIBELE BERENICE CASTELLA PERGHER
Externa à Instituição - MARIA VERONILDA MACÊDO SOUTO