Nb-containing hematites Fe2-xNbxO3: The role of Nb5+ on the reactivity in presence of the H2O2 or ultraviolet light
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Data
2009-03-31
Autores
Silva, Adilson C.
Oliveira, Diana Q. L.
Oliveira, Luiz C. A.
Anastacio, Alexandre S.
Ramalho, Teodorico C.
Lopes, Joao H.
Carvalho, Hudson W. P. [UNESP]
Torres, Claudia E. Rodriguez
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Editor
Elsevier B.V.
Resumo
A series of Nb-containing hematites, Fe-2-xNbxO3 (%Nb = 0.00, 1.49, 5.00 and 9.24) was prepared using the conventional co-precipitation method. Mossbauer and temperature-programmed reduction (TPR) measurements suggested the formation of the crystalline phase with partial substitution of Fe3+ by Nb5+ in the structure. N-2 adsorption/desorption revealed that the presence of Nb has a remarkable effect on the textural properties of the material with an increase in the BET surface area. The reactivity of Fe2-xNbxO3 was investigated using the oxidation of the methylene blue dye used as a model pollutant. The obtained results showed that the presence of Nb seems not to act directly promoting the H2O2 decomposition, but improving the dye oxidation. The analysis using the ESI-MS technique showed partial oxidation observed through different intermediates before the mineralization. This suggests the use of Nb-doped hematite as an efficient catalyst in degradation reactions in the presence of H2O2 or ultraviolet light. (C) 2009 Elsevier B.V. All rights reserved.
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Palavras-chave
Hematite, Niobium, Organic oxidation, ESI-MS
Como citar
Applied Catalysis A-general. Amsterdam: Elsevier B.V., v. 357, n. 1, p. 79-84, 2009.