Banca de DEFESA: LUCAS OLIVEIRA DO ROSÁRIO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LUCAS OLIVEIRA DO ROSÁRIO
DATE: 30/01/2023
TIME: 09:00
LOCAL: videoconferência
TITLE:

Synthesis and characterization of SrMoO4/g-C3N4 prepared via hydrothermal tratment: a study of optical and photocatalytic properties.

KEY WORDS:

photocatalysis; SrMoO4; g-C3N4; heterostructures; semiconductors

PAGES: 107
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Química de Interfaces
SUMMARY:

The inappropriate dumping of organic effluents in aquatic ecosystems has raised the need for new technologies for water treatment, capable of definitively reducing the concentration of these compounds in the environment. In this scenario, Advanced Oxidative Processes based on semiconductor photocatalysts, such as strontium molybdate (SrMoO4), emerges as an appropriate alternative to promote the degradation of organic pollutants into non-toxic substances. However, SrMoO4 in its pure phase normally has unfavorable photocatalytic properties. A potentially effective strategy to overcome such limitations is the construction of a heterostrtured photocatalyst with the polymeric semiconductor g-C3N4. Thus, SrMoO4 particles and SrMoO4/xg-C3N4 heterostructures were synthesized via a co-precipitation route with additional hydrothermal treatment for different heating times at a fixed temperature of 140 °C. In order to evaluate the influence different percentages of g-C3N4 the SrMoO4 structure and the synergistic effect resulting from the interface interaction between both, the powders were structurally characterized by X-ray diffraction and Raman spectroscopy, in which it was possible to verify the obtaining of the pure phase of SrMoO4 and the composite phase of SrMoO4/xg-C3N4. Optical analysis by ultraviolet visible spectroscopy revealed that g-C3N4 can considerably decrease the SrMoO4 gap, while the heterojunction mechanism estimated for SrMoO4/g-C3N4 suggests an increase in the lifetime of photogenereated loads. Such characteristics indicate the possibility of obtaining a material with improved photocatalytic properties, which were later verified through photocatalytic tests of methylene blue under UV and solar light, with results above 74 and 97%, respectively. In addition, the heterojunctions showed excellent absorption capacity in the middle of the cationic dye system.

COMMITTEE MEMBERS:
Externa ao Programa - 1802888 - FABIANA VILLELA DA MOTTA - nullInterno - 1804366 - JÚLIO CÉZAR DE OLIVEIRA FREITAS
Externo à Instituição - LUÍS PRESLEY SEREJO DOS SANTOS - UNIFESP
Presidente - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE