ZNO and AG-ZNO crystals: synthesis, characterization, and application in heterogeneous photocatalysis
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Data
2016-05
Autores
Lucilha, Adriana Campano
Silva, Marcelo Rodrigues Da
Ando, Rômulo Augusto
Dall'antonia, Luiz Henrique
Takashima, Keiko
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Química
Resumo
ZnO and Ag-ZnO were synthesized in a simple and efficient manner by thermal decomposition of zinc oxalate and silver/zinc mixed oxalate. The influence of the addition of metallic silver on ZnO particles and the effect of temperature in the thermal treatment were investigated. The samples were characterized by thermogravimetric analysis, Raman, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, specific surface area (Brunauer-Emmett-Teller) and diffuse reflectance spectroscopy. The photocatalytic activity of these materials in the decolorization of direct red 23 diazo dye was studied. The complete conversion into oxides from oxalates at lower temperatures was determinant in the photocatalytic efficiency of both the oxides. The presence of silver in zinc oxide, treated at 400 °C, more than doubled the rate constant of diazo dye decolorization (6.87×10-3 min-1) with respect to ZnO, treated at 600 °C, resulting in 3.07×10-3 min-1 under UV irradiation at 30 °C.
Descrição
Palavras-chave
oxide semiconductor, surface modification, thermal treatment, direct red 23
Como citar
Química Nova. Sociedade Brasileira de Química, v. 39, n. 4, p. 409-414, 2016.