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Journal of Nanotechnology
Volume 2012 (2012), Article ID 323145, 6 pages
http://dx.doi.org/10.1155/2012/323145
Research Article

C o F e 2 O 4 - F e 3 O 4 Magnetic Nanocomposites as Photocatalyst for the Degradation of Methyl Orange Dye

1Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039, India
2Central Instrument Facility, Indian Institute of Technology Guwahati, Guwahati 781039, India

Received 23 May 2012; Accepted 10 July 2012

Academic Editor: Mallikarjuna Nadagouda

Copyright © 2012 Debabrata Mishra et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We report the investigation of temperature-dependent magnetic properties and photocatalytic activity of C o F e 2 O 4 - F e 3 O 4 magnetic nanocomposites (MNCs) synthesized by hydrothermal process. Room-temperature magnetic hysteresis (M-H) loops result enhanced saturation magnetization of 90 emu/g and coercivity ( 𝐻 𝐶 ) of 530 Oe for C o F e 2 O 4 - F e 3 O 4 MNCs. With decreasing temperature to 20 K, 𝐻 𝐶 increases from 500 Oe to 6800 Oe, and the M-H loops exhibit exchange coupling feature between C o F e 2 O 4 and F e 3 O 4 . Low- and high-temperature-dependent magnetization measurements confirm that the blocking temperature lies above 300 K and the presence of two magnetic phase transitions corresponding to C o F e 2 O 4 and F e 3 O 4 , respectively. The photocatalytic activity of the MNCs has been examined on the reduction of methyl orange (MO), a colored compound used in dyeing and printing textiles. The observed results suggest that the C o F e 2 O 4 - F e 3 O 4 MNCs act as an excellent photocatalyst on the degradation of organic contaminants and degrade 93% of MO in 5 hours of UV irradiation. The photocatalytic activity of MNCs is attributed to remarkably high band gap energy and small particle size. Also, the MNCs with a reproducible photocatalytic activity are well separable from water media by applying external magnetic field and acts as a promising catalyst for the remediation of textile wastewater.