Xiangyu Hou

Magnetic and high rate adsorption properties of porous Mn1−xZnxFe2O4 (0 ⩽ x ⩽ 0.8) adsorbents

Porous spinel ferrites Mn(1-x)Zn(x)Fe(2)O(4) (0 ≤ x ≤ 0.8) are synthesized by a simple sol-gel method with egg white. All samples exhibit porous morphologies and large BET surface area (S(BET)). The substitution of Zn(2+) affects the magnetic properties of ferrites and the adsorption properties of methylene blue (MB) on ferrites, obviously. The saturation magnetization (Ms) of Mn(1-x)Zn(x)Fe(2)O(4) increases before x=0.4, and decreases with further increase of Zn(2+) substitution. This can be ascribed to the changes of the cationic distribution and the variation of spin arrangement in A-site and B-site of spinel structure. All samples show high adsorption capacity and the removal efficiencies of MB reach up to >90% within 3 h. The Zn(2+) substitution accelerates the adsorption rate and capacity of MB on Mn(1-x)Zn(x)Fe(2)O(4). The quickest adsorption occurred at x=0.2 and the largest adsorption capacity occurred at x=0.8.

Synthesis of 3D porous ferromagnetic NiFe2O4 and using as novel adsorbent to treat wastewater

Three dimensions (3D) porous NiFe(2)O(4) is synthesized by a sol-gel method using egg white. The obtained NiFe(2)O(4) shows both good ferromagnetic properties and high adsorption capacity. The porous NiFe(2)O(4) shows good adsorption properties for organic dyes (Methylene Blue (138.50 mg/g), Fuchsine Red (14.61 mg/g), Methyl Violet (19.06 mg/g)) and heavy metal ions (Cu (II) (55.83 mg/g), Cr (VI) (36.95 mg/g) and Ni (II) (37.02 mg/g)) due to its 3D interconnected porous structure. The maximum adsorption of Methylene Blue (MB) fit the pseudo-second-order model and Langmuir isotherm equation well. More interestingly, the ferromagnetic NiFe(2)O(4) can be separated under a magnetic field conveniently and keeps high removal efficiency (>97%) during seven reusable cycles. These results suggest that the porous NiFe(2)O(4) is a promising favorable and reusable adsorbent.

Preparation and Magnetic Property of La0.7Sr0.3MnO3 Nanorod by Combination Sol-Gel with Molten Salt

La0.7Sr0.3MnO3(LSMO) nanorods were synthesized by a method combining sol-gel with molten salts at 950 °C for 10 h, which employed KCl+NaCl(mass ratio 4:1) as eutectic molten salts. The morphologies and magnetic properties of the resulting LSMO nanorods were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), and vibrating sample magnetometer(VSM) measurements. It was found that the obtained perovskite manganite LSMO was a uniform nanorod with a diameter of about 50 nm and a length of longer than 500 nm. The Curie temperature(Tc) of the LSMO nanorod used here was 262 K, much lower than that of bulky single crystal LSMO(360 K). The low Curie temperature might be a result of the great disorder near the grain boundary, which could be observed clearly from the TEM picture.