Gabriela Spirandelli dos Santos
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Clarice Moreira Goes
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Juliana Giancoli Martins de Sousa
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Nicolas Perciani de Moraes
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Livia Chaguri
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This study is focused on the evaluation of the Rhodamine B photodegradation using ZnO/carbon xerogel composite as a photocatalyst, in order to enhance the photocatalytic process efficiency under visible light. The proposed synthesis employs tannin as a precursor for the carbon xerogel,
which enhances the economic and environmental aspect of the composite. The synthesized materials have the hexagonal structure of the zinc oxide (wurtzite), which is homogeneously distributed on the carbonaceous matrix. The diffuse reflectance test shows that light absorption was significantly
enhanced for the composite. The solar light-driven photodegradation results revealed that the synthesized composite achieved virtually complete degradation of the dye present in the solution in less than 3 h, in all concentrations tested. The results of visible light driven photocatalysis
showed that the carbonaceous material presents better photoactivity than the pure oxide (70% and 40% degradation of Rhodamine B, respectively), due to the synergistic effect between the carbon xerogel and zinc oxide on the properties of the composite. The photocatalytic mechanism main active
species are the photogenerated vacancies and superoxide radicals.
A visible-light phototransistor based on the heterostructure of ZnO and TiO2 with trap-assisted photocurrent generation
