Estudo da atividade fotocatalítica e fotoluminescente de filmes multicamadas de CuO/ZnO depositados por spin coating

• Ano de defesa: 2019
• Autor(a) principal: Nascimento, Girlene Gonçalves do
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM CIÊNCIA E ENGENHARIA DE MATERIAIS
• Palavras-chave em Português: Óxido de zinco; Óxido de cobre; Precursores poliméricos; Fotocatálise; Fotoluminescência; Filmes finos; CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA
• Link de acesso: https://repositorio.ufrn.br/jspui/handle/123456789/27924

Recent studies investigate a new inorganic materials class which appears as a promising option for high performance applications in photoluminescence and photocatalysis field. Material development has opened new prospects of development photoluminescence and photocatalysis devices highly efficient which presented a particular relevance for reduction of effluent pollution from both industrial sources. Among the promising technological applications materials, the semiconductors ZnO and CuO stand out, due to a good performance of photocatalytic and optical properties. In this work, zinc oxide and copper oxide resins have been synthesized by polymeric precursors method, being deposited in multilayers on a silicon substrate, using the spin coating technique. The resins have been deposited in 6 layers ZnO/CuO; CuO/ZnO; CuO/CuO and ZnO/ZnO and, they have been heattreated with temperatures 400ºC and 500ºC. The specimens were characterized by Xray diffraction (DRX), UV/VIS spectroscopy, atomic force microscopy (AFM), scanning electron microscopy with field emission (MEV-FEG) and an energy dispersive X-ray spectrometer (EDS). The results of the X-ray analysis confirmed that there has been insufficient chemical interaction to form secondary stages among the oxides, in other words, multilayers have been formed. Absorption spectra UV/VIS characterized the thin as semiconductors, indicating optical gap from 1,53 eV to 3,35 eV. Scanning electron microscopy with field emission (MEV-FEG) showed films are homogenous and presented average pore size 25nm. Photoluminescent films emissions in multilayers change due to a decrease on the electronic recombination. Results of degradation from the cationic dye methylene blue show that pure films presents a diminished capacity compared to the films in the multilayers; and calcination at rising temperature and the increased of roughness improving catalytic performance of the films. The samples at multilayers CUZN400 and CUZN500 possessed the capability to degrade 98% of the blue dye in 120 minutes of sun exposition without addition of any other reagent to improve the photocatalytic capacity.