Banca de QUALIFICAÇÃO: MARCOS ROBERTO DA SILVA VICENTE

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARCOS ROBERTO DA SILVA VICENTE
Date: 23/04/2026
TIME: 14:00
LOCAL: https://conferenciaweb.rnp.br/sala/juliana-255
TITLE:

Development of Photocatalysts Based on BiVO₄/WO₃ Heterojunctions and Persistent Luminescent Sr₂MgSi₂O₇:Eu²⁺,Dy³⁺ Materials

PAGES: 59
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Foto-Química Inorgânica
SUMMARY:

The increasing presence of emerging contaminants in aquatic systems represents a significant environmental challenge, demanding the development of efficient technologies for their removal. Among these pollutants, pharmaceuticals such as tetracycline exhibit high persistence and limited removal in conventional treatment processes. In this context, semiconductor-based photocatalytic processes have been widely explored as promising alternatives for degrading such contaminants.
In this work, the synthesis, characterization, and photocatalytic application of BiVO₄/Sr₂MgSi₂O₇:Eu²⁺;Dy³⁺ (SMSO) heterojunctions prepared with different mass ratios were investigated. The materials were synthesized through microwave-assisted routes, enabling rapid preparation and improved control of structural properties. BiVO₄ acts as a visible-light-absorbing semiconductor, while the luminescent SMSO matrix exhibits persistent emission and charge-storage capability. This combination creates optical complementarity between the components, in which the light absorption of BiVO₄ is coupled with the emission and energy-storage properties of SMSO. The materials were characterized using structural, optical, electrochemical, and photoluminescence techniques to elucidate charge-transfer and storage dynamics. The results indicate that heterojunction formation promotes the redistribution of charge carriers across kinetically distinct states and providing evidence of electron storage in SMSO.
SMSO and the heterojunctions exhibited higher activity than pristine BiVO₄, achieving degradation efficiencies of 90% or higher under continuous and on/off irradiation. The 1:1 composition showed particularly favorable performance, reflecting an optimal balance between light absorption, charge storage, and interfacial transfer. These results demonstrate that the mass ratio between BiVO₄ and SMSO plays a key role in controlling charge carrier kinetic connectivity and the energetic efficiency of the photocatalytic process, highlighting the coupling between charge storage and surface reactivity as a promising strategy for the development of efficient visible light-driven photocatalysts.

 

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 2351974 - JULIANA DOS SANTOS DE SOUZA SILVA
Membro Titular - Examinador(a) Externo à Instituição - HERMI FELITNO DE BRITO
Membro Titular - Examinador(a) Externo à Instituição - JÚLIO CÉSAR MARTINS DA SILVA - UFF
Membro Suplente - Examinador(a) Interno ao Programa - 1601156 - WAGNER ALVES CARVALHO