Improved photocatalytic activity of d-FeOOH by using H2O2 as an electron acceptor.
In this work, d-FeOOH nanoparticles were synthesized by a simple co-precipitation method and used as a photocatalyst in the presence of H2O2 for the oxidation of Rhodamine B (RhB) dye under artificial light. The d-FeOOH was characterized by powder X-ray diffraction, 57Fe Mössbauer spectroscopy, N2 a...
| Autores: | , , , , , |
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| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2017 |
| País: | Brasil |
| Recursos: | Universidade Federal de Ouro Preto (UFOP) |
| Repositório: | Repositório Institucional da UFOP |
| Idioma: | inglês |
| OAI Identifier: | oai:repositorio.ufop.br:123456789/9589 |
| Acesso em linha: | http://www.repositorio.ufop.br/handle/123456789/9589 https://doi.org/10.1016/j.jphotochem.2016.08.013 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Iron oxides Dye oxidation Photodegradation Photocatalysts |
| Resumo: | In this work, d-FeOOH nanoparticles were synthesized by a simple co-precipitation method and used as a photocatalyst in the presence of H2O2 for the oxidation of Rhodamine B (RhB) dye under artificial light. The d-FeOOH was characterized by powder X-ray diffraction, 57Fe Mössbauer spectroscopy, N2 adsorption/desorption and UV–vis diffuse reflectance measurements. The d-FeOOH nanoparticles have high specific surface area (101 m2 g 1) and optical bandgap energy of 2.02 eV. Under artificial light, only 59% of RhB (100 mL; 20 mg L 1) was photocatalytically degraded by d-FeOOH in 60 min reaction. However, after adding H2O2, the photocatalytic activity of d-FeOOH was significantly improved, reaching 87% of dye removal. Tests using scavengers of reactive species and EPR analysis revealed that h+ and OH are the main species in this system. Based on the experimental results, the mechanism of RhB photodegradation in the presence of d-FeOOH and H2O2 was proposed. By this mechanism, the OH can be formed by direct water oxidation or by H2O2 reduction, as the electron transfer from the conduction band of d-FeOOH to H2O2 is thermodynamically favorable. Moreover, the H2O2 retards the electron-hole recombination in d-FeOOH, thus increasing its photocatalytic activity. Given its high efficiency for degrading RhB in water, d-FeOOH revealed to be a promising photocatalyst to be tested in the oxidation of emerging pollutants for the environmental decontamination. |
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