Banca de QUALIFICAÇÃO: FERNANDO RODRIGO DANTAS FERNANDES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : FERNANDO RODRIGO DANTAS FERNANDES
DATE: 14/07/2023
TIME: 08:30
LOCAL: videoconferência
TITLE:

Development of mesoporous silicon-cerium and silicon-titanium nanospheres via soft-template synthesis.

KEY WORDS:

Mesoporous materials; Nanospheres; Cerium; Titanium; soft-template

PAGES: 100
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SUMMARY:

The present work aimed to develop mesoporous nanospheres composed of Silicon-Cerium and Silicon-Titanium through the soft-template method. The methodology basically consisted of using CTAB micelles as a soft mold, and sources of silicon, cerium and titanium for the composition of the inorganic structure in the formation of nanospheres. The syntheses were performed using different Si/Ce and Si/Ti ratios in order to evaluate the influence of the amount of metals in obtaining the nanospheres. The obtained materials were evaluated in structural, textural and morphological character, through the techniques of DRX, FRX, EDS, Adsorption and Desorption of N2 and SEM. The Si-Ti nanospheres did not show diffraction peaks referring to any phase of titanium oxide, indicating that the metal is actually found in the structure of the nanospheres, however for Si-Ce materials it is noticed that high amounts of Cerium can lead to unwanted CeO formation. SEM images demonstrated the formation of well-defined spheres, for both metals, with diameters between 50 and 400 nm. A uniform scattering of Ce and Ti was observed in all materials, which indicates that these metals are indeed participating in the composition of the inorganic structure of the nanospheres, corroborating the results of XRD. The proposed soft-template method proved to be effective, enabling the synthesis, in a short time, of Si-Ce and Si-Ti nanospheres, with potential for application and photocatalysis reactions.

COMMITTEE MEMBERS:
Externo à Instituição - ADONAY RODRIGUES LOIOLA - UFC
Externa à Instituição - ANNE GABRIELLA DIAS SANTOS - UERN
Externa à Instituição - MARIELE IARA SOARES DE MELLO - UFRN
Presidente - 1308577 - SIBELE BERENICE CASTELLA PERGHER
Interno - 2087667 - TIAGO PINHEIRO BRAGA