Banca de QUALIFICAÇÃO: RONIER ALCANTARA OLIVEIRA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : RONIER ALCANTARA OLIVEIRA
DATE: 07/07/2022
TIME: 09:00
LOCAL: Sala virtual (videoconferência)
TITLE:

Influence of the method of obtaining Bi2MoO6:ZnO heterostructures for photocatalytic application

KEY WORDS:

sonochemistry; Bi₂MoO₆; ZnO; heterostructure; microwave; photocatalysis

PAGES: 81
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Cerâmicos
SUMMARY:

Tthe high consumption and inappropriate disposal of industrial products, from clothes to food products, increasing society's interest in developing materials that have catalytic properties that use means for the degradation of these organic contaminants, which can be dyes, pharmaceutical compounds and among others. The degradation reaction is accelerated using electromagnetic radiation, potential difference or ultrasonic radiation. In this work, the microwave-assisted hydrothermal method was used simultaneously with the sonochemical method (route 1) and only the sonochemical method (route 2) to obtain Bi₂MoO6/ZnO heterostructures, with mass ratios of 1:1, 1 :2, 1:4, 1:8, 2:1, 4:1 and 8:1. The particles obtained were characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (SEM-FEG) and spectroscopy in the ultraviolet visible region (UV-Vis). To evaluate the photocatalytic properties, a photodegradation test was performed against methylene blue and rhodamine B dyes. The XRD results indicated the presence of the phases of ZnO with hexagonal structure and Bi₂MoO₆ with orthorhombic phase. The formation of a secondary phase of bismuth molybdate (Bi₄MoO₉) in route 1 was observed. Raman spectroscopy revealed the standard vibrational modes of the phases obtained from Bi₂MoO₆/ZnO, and also confirmed the presence of the secondary phase. The images obtained by SEM-FEG showed an irregular and predominant morphology in route 1, typical of the secondary phase of molybdate, and in route 2, flake-like morphology was obtained for molybdate and rods and flowers for zinc oxide. The heterostructures with a 1:1 ratio showed absorption for longer wavelengths and smaller bandgap, indicating a high photocatalytic efficiency against methylene blue and rhodamine B dyes. The reuse cycles indicated high potential for practical application in wastewater, due to the ability of consecutive cycles for photodegradation, even with the reduction of the photocatalytic efficiency due to the adsorption of the dye in the samples.

COMMITTEE MEMBERS:
Presidente - 1802888 - FABIANA VILLELA DA MOTTA
Interno - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE
Externo à Instituição - THIAGO MIELLE BRITO FERREIRA OLIVEIRA - UFCA
Externa à Instituição - LAURA XIMENA LOVISA - UNIFEI