Banca de QUALIFICAÇÃO: ALAN JONES LIRA DE MELO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ALAN JONES LIRA DE MELO
DATE: 10/12/2024
TIME: 09:00
LOCAL: https://meet.google.com/ezo-qiey-cme
TITLE:

Obtaining doped and co-doped TiO2 nanofibers with Nd and Sm by electrospinning: Study of photocatalytic activity in phenol and norfloxacin

KEY WORDS:

TiO2, nanofiber, Electrospinning, Photocatalysis, Phenol, Norfloxacin

PAGES: 104
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Cerâmicos
SUMMARY:

Compounds such as pharmaceuticals and phenol are a growing environmental concern, entering ecosystems due to the improper disposal of drugs, industrial waste, and domestic sewage. Prolonged exposure to these pollutants can cause antimicrobial resistance and toxicity to aquatic organisms, affecting their reproduction and altering aquatic communities. Advanced oxidation processes (AOPs) are effective solutions for degrading organic pollutants and are widely used in wastewater treatment. TiO2, present on the Earth's surface, has excellent photocatalytic properties, especially when doped with metal ions, and is commonly used in this type of treatment. In this study, TiO2 ceramic nanofibers were doped and co-doped with Nd3+ and Sm3+ ions at concentrations of 0.5%, 1.0%, and 1.5% using the electrospinning method, followed by heat treatment. The structural properties of the nanofibers were analyzed by X-ray diffraction (XRD), Raman spectroscopy, and FT-IR. In contrast, the morphology was studied by scanning electron microscopy (FEG-SEM) and BET. Optical characterization included diffuse reflectance spectroscopy (UV-Vis), photoluminescence, and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity was evaluated by the degradation of norfloxacin and phenol under UV radiation, complemented by toxicity tests. XRD patterns confirmed the presence of only the anatase phase of TiO2, even after doping. SEM analysis revealed uniform and continuous nanofibers, randomly arranged, and BET indicated an increase in surface area after doping. UV-Vis spectroscopy showed that the band gap was modified by doping and co-doping, with characteristic peaks of Nd and Sm present in the photoluminescence. Photocatalytic tests indicated a degradation of 99.99% for phenol with NF T0.5NS and 99.90% for norfloxacin with NF T1.5NS, under UV radiation, which was confirmed by the antimicrobial activity test, in which no halo was formed in the degraded solution. To evaluate the reusability of the photocatalysts, the NFs were subjected to four reuse cycles, with NF T0.5NS presenting 43% efficiency and NF T1.5NS, 82% after the cycles.

COMMITTEE MEMBERS:
Interna - 1802888 - FABIANA VILLELA DA MOTTA
Interno - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE
Externo ao Programa - 2367881 - ROGERSON RODRIGUES FREIRE RAMOS - UFRNExterna à Instituição - LAURA XIMENA LOVISA - UFSC
Externo à Instituição - NEFTALÍ LENIN VILLARREAL CARREÑO - UFPel