Banca de QUALIFICAÇÃO: LUCAS OLIVEIRA DO ROSÁRIO
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.STUDENT : LUCAS OLIVEIRA DO ROSÁRIO
DATE: 08/11/2022
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; co-precipitation; semiconductors.
PAGES: 99
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Foto-Química Inorgânica
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 (AOPs) 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 due to its high band gap value and the high rate of recombination of the electron-hole pair. 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 of the incorporation 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 assays of methylene blue. In addition, the heterojunctions showed excellent absorption capacity in the middle of a cationic dye system.
COMMITTEE MEMBERS:
Presidente - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE
Externa ao Programa - 1802888 - FABIANA VILLELA DA MOTTA - UFRNExterno à Instituição - LUÍS PRESLEY SEREJO DOS SANTOS - UNIFESP