Banca de DEFESA: VIVIANE PAPA DA SILVA
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.STUDENT : VIVIANE PAPA DA SILVA
DATE: 01/03/2024
TIME: 14:00
LOCAL: Sala de seminários
TITLE:
SYNTHESIS AND CHARACTERIZATION OF METALLOPHTALOCYANINE COORDINATION COMPOUNDS OCCLUDED IN ZEOLITE Y FOR NOx SENSING
KEY WORDS:
Ship-in-the-bottle method; metallophthalocyanines; zeolites; sensors; NOx.
PAGES: 150
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Físico Química Inorgânica
SUMMARY:
There is a growing search for selective and sensitive materials that can be used as gas sensing agents. These materials need to present certain characteristics, such as reusability and high resistance, in order to be effectively used. Among the species most used for this purpose are coordination compounds. These molecules are widely used because they present properties that can be monitored when chemically interacting with various gases, such as luminescence and variation in the oxidation state. Within this context, metalphthalocyanines gain prominence, as they are materials that present high stability and unique electrochemical properties, being able to interact in a coplanar way with several molecules. The synthesis of these compounds occluded in zeolites constitutes a system that has been studied over the last 30 years, with the aim of promoting shape selectivity to the materials obtained. This synthesis occurs by inserting fragments of the compound into zeolites previously exchanged with the ions of interest, a method called ship-in-the-bottle. Once obtained, these materials present a series of advantages due to greater conservation of the active site and the reduction of the coplanar interaction phenomenon, which results in phthalocynanine aggregates. Despite being a known synthesis, the ship-in-the-bottle process of phthalocyanines in zeolites constitutes a challenge, especially with regard to the characterization and location of these compounds in nanoporous materials. However, once obtained, these materials can be used in a wide variety of applications. The use of NOx gases as sensors is of great interest, as these are gases emitted into the atmosphere from various anthropogenic sources. In this work, the synthesis and characterization of phthalocyanines of copper(ll), cobalt(ll), nickel(ll) and iron(ll), pure and occluded in Y zeolites, were carried out. These materials were characterized using X-ray diffraction techniques. , energy-dispersive X-ray spectrometry, infrared spectroscopy, UV-Vis absorption spectrometry, cyclic voltammetry, thermogravimetry and textural characterization by N2 physisorption. The electrochemical potential of these materials was studied by cyclic voltammetry using chemically modified electrodes. The electrochemical analyses carried out showed good performance of materials containing cobalt phthalocyanine occluded in zeolite Y for detecting NO gas.
COMMITTEE MEMBERS:
Presidente - 2356272 - ARTUR JOSE SANTOS MASCARENHAS
Interna - 1861434 - VALERIA CRISTINA FERNANDES
Interna - 1299469 - LUCIANA ALMEIDA DA SILVA
Interna - 3156252 - LUIZA AMIM MERCANTE
Externo ao Programa - 1104702 - MAURICIO BRANDAO DOS SANTOS - UFBAExterno à Instituição - RODRIGO DE PAULA - UFRB
Externa à Instituição - ELIANA MIDORI SUSSUCHI - UFS
Externa à Instituição - TEREZA SIMONNE MASCARENHAS SANTOS - UEFS