Banca de DEFESA: SAMUEL BRITO FERREIRA SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : SAMUEL BRITO FERREIRA SANTOS
DATE: 17/02/2022
TIME: 16:00
LOCAL: https://meet.google.com/dwf-jiir-vzy
TITLE:

Photocatalytic potential of CoFe2O4:TiO2 nanostructure activated by UVC radiation for degradation of organic contaminants

KEY WORDS:

OIL FIELD PRODUCED WATER; PHOTOCATALYSIS; MAGNETIC  NANOPARTICLES.

PAGES: 51
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Tecnologia Química
SPECIALTY: Tratamentos e Aproveitamento de Rejeitos
SUMMARY:

The concern with water resources contamination as result of petrochemical residues, or from the oil spill, has contributed in the search for systems to treat those effluents, capable of reducing the load of these pollutants to acceptable levels for correct disposal. In the present study, CoFe₂O₄ magnetic nanoparticles and CoFe₂O₄:TiO₂ (30:70) nanostructures were synthesized via solvothermal route. Those materials were characterized by XRD, FTIR, size distribution, and textural analysis (BET). The application of the nanostructures for the organic contaminant (Erionyl Red A-3G) degradation process were evaluated by adsorption kinetics and isotherms. The photocatalytic tests evaluated the initial pH (2, 3, and 4) and the catalyst concentration (0.1, 0.55, and 1.0 g/L) influence by an experimental design 2² + 3 central points. The diffractograms identified the MNPs (CoFe₂O₄) monophasic synthesis and the nanostructures with anatase as the main phase and CoFe₂O₄ as the second phase. The spectra confirmed the spinel formation and the metal-oxygen bond from TiO₂. The particle size distribution revealed the MNPs nanometric scale and the dimension of the nanostructures prepared with TiO₂. Cobalt ferrite showed absorption in the entire UV-Vis spectrum, TiO₂ exhibited absorption only in the UV region, and the heterojunctions (CoFe₂O₄:TiO₂) showed the contribution of ferrite in increasing the absorption in the visible region. The materials presented optical band gaps of 1,38 eV (CoFe₂O₄), 3,15 eV (TiO₂), 2,75 eV (70Ti), and 1,76 eV (50Ti). The textural analysis indicated the formation of a mesoporous nanostructure, with a surface area of 6.34 m²/g and pore volume of 0.04 cm³/g. The adsorption tests reached equilibrium in 15 min (10 and 20 ppm) and in 18 min (100 ppm), with an isotherm described by the Freundlich model (R² = 0.999). The photocatalytic tests showed significant effects of initial pH and catalyst concentration on the Erionyl Red A-3G degradation, with an optimal condition at pH 2 and 1.0 g/L of catalyst, reaching 100% degradation within 60 min. The CoFe₂O₄:TiO₂ nanostructures showed potential for organic contaminants degradation, with magnetic characteristics and the possibility for future tests on petroleum industry effluents treatment.

BANKING MEMBERS:
Presidente - 1149554 - OSVALDO CHIAVONE FILHO
Externo à Instituição - ANDRE LUIS NOVAIS MOTA - UFERSA
Externo à Instituição - EDSON LUIZ FOLETTO - UFSM