Notícias

Banca de QUALIFICAÇÃO: JOAO FERREIRA DA CRUZ FILHO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE: JOAO FERREIRA DA CRUZ FILHO
DATA: 15/03/2024
HORA: 14:00
LOCAL: Auditório do Geratec-UESPI
TÍTULO: Enhanced photocatalytic degradation of the levofloxacin antibiotic on Ag3PO4/UMOFNs heterojunction irradiated by WLEDs
PALAVRAS-CHAVES: Advanced oxidation process, emerging pollutant, wastewater treatment, heterogeneous photocatalysis, PET recycling
PÁGINAS: 50
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Físico-Química
ESPECIALIDADE: Cinética Química e Catálise
RESUMO:

This work presents the synthesis, characterization and photocatalytic activity of the Ag3PO4/UMOFNs(x) heterojunction (where x = 5, 10 and 20 wt.%) in the degradation of the antibiotic levofloxacin (LVX) under white light-emitting diodes (WLEDs). MOFs, UMOFNs (ultrafine metal-organic structure nanosheets) and Ag3PO4 were synthesized via hydrothermal, sonication-exfoliation and precipitation methods, respectively. The Xray diffraction (XRD) standards, as well as the structural refinement methods, demonstrated that MOFs and Ag3PO4 have triclinic crystalline phases with P 1 (2) space group and cubic centered body with space group P43n (218) space group, respectively. The results of micro-Raman and FT-IR, X-ray photoelectron spectroscopy (XPS), thermogravimetric analyses (TGA), SEM/EDS, and Zeta potential (º), indicated that in addition to the chemical composition, the samples have good thermal stability (≈ 450 °C) and spherical, tabular and lamellar morphology for the samples Ag3PO4, MOF and UMOFNs, respectively, with specific surface load in the range of −19.8 mV to −45.1 mV. UV-vis diffuse reflectance spectroscopy (DRS) revealed that the band-gap energy of the UMOFNs was ≈ 3.14 eV, while the Ag3PO4 sample showed a band-gap energy (Eg) ≈ of 2.50 eV, with no significant variation of the Eg values for the synthesized heterojunctions. The Ag3PO4 sample as well as the Ag3PO4/UMOFNs(x) heterojunctions (x = 5, 10 and 20% by weight) showed LVX degradation efficiency under WLEDs irradiation of 92.5, 81.0, 75.0% and 70.0%, respectively, under low relative power density 11.0 mW.cm-2 at 60 min of the first photocatalytic test. In the third photocatalytic cycle, the catalytic efficiency of Ag3PO4 dropped to ≈ 6%, while Ag3PO4/UMOFNs(x) remained at ≈ 36%, which evidences the inhibitory effect of UMOFNs on the photocorrosion of Ag3PO4. In addition, the radical scavenging experiment showed that *OH and *O2- were the most reactive species in the photocatalytic process.


MEMBROS DA BANCA:
Presidente - 756.483.183-91 - GERALDO EDUARDO DA LUZ JUNIOR - UESPI
Interno - 1553988 - EDSON CAVALCANTI DA SILVA FILHO
Interno - 050.406.403-74 - FRANCISCO XAVIER NOBRE - UFAM
Externo à Instituição - GILVAN MOREIRA DA PAZ - IFPI
Notícia cadastrada em: 11/03/2024 11:07
SIGAA | Superintendência de Tecnologia da Informação - STI/UFPI - (86) 3215-1124 | © UFRN | sigjb03.ufpi.br.sigaa 17/06/2024 20:11