Banca de DEFESA: MAX TAYLO ARAÚJO LIMA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MAX TAYLO ARAÚJO LIMA
DATE: 03/08/2022
TIME: 10:00
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:

Development of Catalysts Based on Metallic Nanoparticles for Organic Chemistry

KEY WORDS:

4-Nitrophenol; Chemical Reduction; Catalysis; Photocatalysis; Silver Nanoparticles.

PAGES: 88
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

Among the compounds known as nitrophenolics, whose applications are present in our daily lives, 4- nitrophenol (4-NP) stands out as a serious environmental contaminant. 4-NP can be reduced to the safety compound 4-aminophenol through the use of silver nanocatalysts. Thus, this work has as the main objective to develop silver nanoparticles (AgNPs) with different stabilizers and formats, to evaluate their catalytic and photocatalytic activity in the 4-nitrophenol reduction reaction. AgNPs were prepared in spherical and prismatic format, using PVP, PVA and AA as stabilizer, through the chemical reduction method. AgNPs were characterized by Uv-Vis spectroscopy, transmission electron microscopy, dynamic light scattering, Zeta potential and ICP-OES. The results obtained indicate the formation of silver nanoparticles with well-defined morphology, spherical and prismatic, with colloidal stability and good size distribution. The catalytic reduction of 4-nitrophenol to 4-aminophenol in the presence of silver nanocatalysts was studied by UV-Vis spectroscopy. The application in catalysis and photocatalysis, indicate a great catalytic potential of AgNPs in the reduction of 4-NF. The spherical AgNPs stabilized with PVA presented a percentage of 94% in the reduction with 2 lamps of total solar spectrum. Nanomaterials with ascorbic acid exhibited a higher catalytic activity for prismatic than spherical nanoparticles, reaching the maximum reduction percentage of 54 and 42%, respectively. AgNPs prepared with PVP showed the worst performance, when compared to the other studied nanoparticles, for most of the systems used. Therefore, from the results obtained, we can conclude that silver nanocatalysts played their role successfully in the reduction of 4-nitrophenol, demonstrating potential application in other chemical reactions, in order to contribute to the development of sustainable nanocatalysts for organic chemistry.

BANKING MEMBERS:
Interno - 2457389 - EDUARDO PADRON HERNANDEZ
Externa ao Programa - 2174335 - IVANI MALVESTITI
Presidente - 2330165 - MARIA GORETI CARVALHO PEREIRA