Tailoring size and structural distortion of Fe3O4 nanoparticles for the purification of contaminated water.
Fe(3)O(4) magnetic nanoparticles with different particle sizes were synthesized using two methods, i.e., a co-precipitation process and a polyol process, respectively. The atomic pair distribution analyses from the high-energy X-ray scattering data and TEM observations show that the two kinds of nanoparticles have different sizes and structural distortions. An average particle size of 6-8 nm with a narrow size distribution was observed for the nanoparticles prepared with the co-precipitation method. Magnetic measurements show that those particles are in ferromagnetic state with a saturation magnetization of 74.3 emu g(-1). For the particles synthesized with the polyol process, a mean diameter of 18-35 nm was observed with a saturation magnetization of 78.2 emu g(-1). Although both kinds of nanoparticles are well crystallized, an obviously higher structural distortion is evidenced for the co-precipitation processed nanoparticles. The synthesized Fe(3)O(4) particles with different mean particle size were used for treating the wastewater contaminated with the metal ions, such as Ni(II), Cu(II), Cd(II) and Cr(VI). It is found that the adsorption capacity of Fe(3)O(4) particles increased with decreasing the particle size or increasing the surface area. While the particle size was decreased to 8 nm, the Fe(3)O(4) particles can absorb almost all of the above-mentioned metal ions in the contaminated water with the adsorption capacity of 34.93 mg/g, which is approximately 7 times higher than that using the coarse particles. We attribute the extremely high adsorption capacity to the highly-distorted surface.
Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, 3 Wenhua Road, Shenyang 110004, China. Shenyf@smm.neu.edu.cn
Y F
YF
Shen
J
J
Tang
Z H
ZH
Nie
Y D
YD
Wang
Y
Y
Ren
L
L
Zuo
D000327:Adsorption; D005290:Ferric Compounds / Q000737:chemistry*; D053768:Metal Nanoparticles; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D012542:Scattering, Radiation; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D014961:X-Ray Diffraction
D005290:Ferric Compounds; D014874:Water Pollutants, Chemical; C000499:ferric oxide