Banca de DEFESA: JESSICA CAROLINE PENA ALVES DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JESSICA CAROLINE PENA ALVES DA SILVA
DATE: 20/12/2023
TIME: 14:00
LOCAL: Sala 303 do Bloco B do Campus de Santo André da Universidade Federal do ABC
TITLE:

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

PAGES: 102
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Determinação de Estrutura de Compostos Inorgânicos
SUMMARY:

TiO₂ and α-Fe₂O₃ are oxides widely investigated for use as photoanodes in processes such as the photoelectrochemical water splitting into H₂ and O₂. Despite being promising materials, these oxides have some drawbacks. TiO₂ has a high band-gap energy (3.2 eV), making it sensitive only to UV radiation. The conduction band of hematite does not have the appropriate potential to reduce H⁺ to H₂, preventing the reaction from occurring at an open-circuit potential, and requiring the application of an external potential for the reaction to occur. One strategy to overcome these disadvantages is to prepare heterojunctions of these materials, which can result in photoelectrocatalysts with improved properties. In this context, the use of microwave radiation in the synthesis of these heterojunctions becomes very attractive. In this work, the synthesis of a heterojunction of TiO₂, α-Fe₂O₃, and graphene oxide was carried out using a one-pot microwave-assisted method. The materials were characterized by scanning electron microscopy, Raman spectroscopy, X-ray diffraction, infrared vibrational spectroscopy, and zeta potential, where the presence of TiO₂ in the anatase phase, reduced graphene oxide, and Fe₂O₃ were identified. Electrochemical characterizations such as linear voltammetry, chronoamperometry, and measurement of the incident photon-to-current conversion efficiency (IPCE) were also performed to determine the photoelectroactivity of the materials. The results suggest better photoelectrochemical performance for the system containing the heterojunction compared to the system in which iron was not incorporated. However, the performance presented is still lower than initially expected, which may be related to mass transport problems and the quantity of graphene oxide in the heterojunction, limiting the efficiency of the photoelectrode.

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
Membro Suplente - Examinador(a) Externo à Instituição - RONDES FERREIRA DA SILVA - CEETEPS