Synthesis and characterization of iron/niobium composites: catalyst for dye wastewater treatments

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Synthesis and Characterization of Iron/Niobium composites: Catalyst for Dye Wastewater Treatments

Carlos C. Rezende a, Jonas L. Netoa,*, Adilson C. Silvab, Verônica M. Limaa, Márcio C. Pereirac, Luiz C. A. Oliveirab
a

Department of Chemistry, Federal University of Lavras, 37200-000 Lavras,Minas Gerais, , Brazil. Department of Chemistry, ICEx, Federal University of Minas Gerais, 31270-901Belo Horizonte,

b

Minas Gerais, Brazil.
c

Institute of Science and Technology, Federal University of Jequitinhonha and Mucuri Valleys,

39803-371 Teófilo Otoni, Minas Gerais, Brazil.

2' 3'
3HC

1' N

1

2 3 4 N CH3
3HC

N N CH3 S

OH

OH N
3HC

OH

N 4' CH3

S 5' 6'

6

5

N CH3 CH3

N CH3

S

N CH3 CH3

I m/z=284

CH3

II m/z=300

III m/z=316Application of niobia-based materials as catalysts for methylene blue oxidation involving hydrogen

CO2

H2O

.......

O OH peroxide and ultraviolet light HO HO O N CH3 OH N CH3
3HC

OH

OH N S N CH3 OH CH3

CH3

CH3

N CH3

VI m/z=161

V m/z=130

IV m/z=332

*Highlights (for review)

Highlights Synthesis e characterization of niobia/iron composites; Catalyticactivity in reactions employing H2O2 or UV light; Reactions involving methylene blue dye solutions: discoloration e total organic carbon removal.

*Manuscript Click here to view linked References

Synthesis and Characterization of Iron/Niobium composites: Catalyst for Dye
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Wastewater Treatments

Carlos C. Rezende a, Jonas L. Netoa,*, Adilson C. Silvab, Verônica M. Limaa, Márcio C. Pereirac, Luiz C. A. Oliveirab

a

Department of Chemistry, Federal University of Lavras, 37200-000 Lavras, Minas Gerais, Brazil. Department of Chemistry, ICEx, Federal University of Minas Gerais, 31270-901 BeloHorizonte, Minas Gerais, Brazil.
c

b

Institute of Science and Technology, Federal University of Jequitinhonha and Mucuri Valleys, 39803-371 Teófilo Otoni, Minas Gerais, Brazil.

* Corresponding author Tel.: +55 35 3829 1515; fax: +55 35 3829 1271. Electronic address: neto.jl@dqi.ufla.br (Jonas L. Neto)

Abstract
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A series of niobium/iron composites, Nb2O5/Fe(III) (%Fe(w/w) = 0.0, 2.0, 2.4 and 7.6), was prepared by conventional co-precipitation method. Powder XRD,
57

Fe Mössbauer spectroscopy,

temperature-programmed reduction and energy dispersive spectroscopy results suggested the formationof Fe-doped niobium oxide with deposition of hematite (-Fe2O3) on the niobium oxide surface when iron percentage increases. The reactivity of the composites was investigated by the oxidation of the methylene blue dye as a model pollutant, in the presence of hydrogen peroxide (Fenton-like process) or ultraviolet light (photocatalytic process). The presence of iron oxide on the materials surfaceprovided an increase in the catalytic activity of the composites when reactions were carried out in the presence of hydrogen peroxide (H2O2). The pure niobia was more effective for the reactions involving ultraviolet light.

Keywords: synthetic niobia; iron oxide; ultraviolet light; hydrogen peroxide.

1- Introduction
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The textile industry consumes large quantities of water and chemicals, mainly in the processes of dyeing and finishing. The effluent usually presents a high concentration and complex composition. Conventional dye wastewater treatment methodologies are becoming inefficient to meet the...
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