Improvement of the photocatalytic activity of magnetite by Mn-incorporation


Autoria(s): Carvalho, Hudson W. P.; Hammer, Peter; Pulcinelli, Sandra Helena; Santilli, Celso Valentim; Molina, Eduardo F.
Contribuinte(s)

Universidade Estadual Paulista (UNESP)

Data(s)

03/12/2014

03/12/2014

01/02/2014

Resumo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mn-incorporated Fe3O4 photocatalysts were prepared by a simple co-precipitation method. Photocatalytic discoloration of Methylene Blue (MB) was used to evaluate the performance of these catalysts. The DSC results have shown that the insertion of Mn into Fe3O4 lattice has increased converting Fe3O4 to gamma-Fe2O3. This is accompanied by a decrease of surface area and of crystallinity, as detected by XRD. The analysis of the chemical environment by XPS has shown that Mn2+ replaces Fe2+ preferentially in the octahedral sites while Mn3+ replaces Fe3+ of inverse spinel sites. The Mn-incorporated samples were significantly more efficient in MB discoloration assisted by UVA irradiation and H2O2. It was also found that ascorbic acid prevents H2O2 decomposition, by scavenging preferentially (OOH)-O-center dot radicals produced at Mn sites. Finally, the results reported here can contribute for a better comprehension of the activity of composite catalysts and the design of efficient systems for discoloration of organic pollutants. (C) 2013 Elsevier B.V. All rights reserved.

Formato

64-69

Identificador

http://dx.doi.org/10.1016/j.mseb.2013.11.008

Materials Science And Engineering B-advanced Functional Solid-state Materials. Amsterdam: Elsevier Science Bv, v. 181, p. 64-69, 2014.

0921-5107

http://hdl.handle.net/11449/111417

10.1016/j.mseb.2013.11.008

WOS:000332445400009

Idioma(s)

eng

Publicador

Elsevier B.V.

Relação

Materials Science and Engineering B: Advanced Functional Solid-state Materials

Direitos

closedAccess

Palavras-Chave #Magnetite catalyst #Manganese doping #Bonding structure #Photocatalytical activity #Colorant degradation #XPS
Tipo

info:eu-repo/semantics/article