Banca de QUALIFICAÇÃO: JESSICA CAROLINE PENA ALVES DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : JESSICA CAROLINE PENA ALVES DA SILVA
DATE: 31/08/2023
TIME: 13:00
LOCAL: https://meet.google.com/wiu-rutg-pwn
TITLE:

PHOTOANODES BASED ON TIO₂ AND GRAPHENE OXIDE FOR APPLICATION IN HYDROGEN GAS PRODUCTION

PAGES: 31
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Determinação de Estrutura de Compostos Inorgânicos
SUMMARY:

Photoelectrochemical water splitting into H₂ and O₂ using semiconductors materials as photoelectrodes is a promising approach for obtaining hydrogen gas (H₂). TiO₂-based photoanodes have been widely investigated for this application due to their natural abundance, chemical stability, non-toxicity, high resistance to photocorrosion and low production cost. However, TiO₂ presents limitations such as low electrical conductivity, limited time in the excited state, and small diffusion distance. Incorporating graphene into TiO₂ increases the photoelectrochemical activity of the resulting material, attributed to the favorable band alignment of the two semiconductors and the properties of graphene that facilitate charge separation. Here we report how the unique interactions of microwaves with the reactional media can produce TiO₂-graphene composites with enhanced properties. The method of synthesis used was adapted from previously reported conventional synthesis, with adaptations for microwave conditions. Also, ammonium sulfate was added as a capping agent to orientate the TiO₂ growth. Raman data show that it was possible to form anatase TiO₂ under all the synthesis conditions investigated. Additionally, it was possible to evaluate the degree of graphene reduction, given that reduced graphene oxide is more conductive. Adding ammonium sulfate to the reaction medium also increases the degree of graphene oxide reduction when the reaction is microwave-assisted but has no impact on conventional synthesis. These differences show that the unique effects of microwave irradiation allow one to obtain materials with characteristics distinct from those observed in materials produced by traditional routes.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 2351974 - JULIANA DOS SANTOS DE SOUZA
Membro Titular - Examinador(a) Externo ao Programa - 3107918 - WILLY GLEN SANTOS
Membro Titular - Examinador(a) Externo à Instituição - IRINA MARINHO FACTORI
Membro Suplente - Examinador(a) Interno ao Programa - 3323134 - LUIZ DUARTE RAMOS