Papers by Keyword: β-FeOOH

Abstract: Abstract. The effects of various parameters and the adsorption isotherms for the Cr(VI) removal by nano β-FeOOH and its innovative composite material with surfactant hexadecyltrimethylammonium bromide (HDTMA) modified zeolite (β-FeOOH/SMZ) were investigated and compared by batch adsorption experiments. The structure information and surface images of nano β-FeOOH and β-FeOOH/SMZ were characterized by X-ray diffraction (XRD) and Field-emission scanning electron microscopy (FE-SEM). From the experimental work, both β-FeOOH and β-FeOOH/SMZ were effective adsorbents in Cr (VI) removal, while β-FeOOH/SMZ was found to show higher adsorptivity than β-FeOOH. Additionally, the isotherm experimental data fits the Langmuir adsorption isotherm more closely, and the maximum adsorption capacity of Cr(VI) on β-FeOOH and β-FeOOH/SMZ can attain 20.79 mg/g and 22.08 mg/g, respectively.

Abstract: Composite electrode materials of amorphous FeOOH-based particles and carbon powder were prepared by heat treatment of composite powder obtained by hydrolyzing of mixed aqueous solutions of FeCl3 and Ti(SO4)2 into which electron conducting carbon powder was dispersed. They exhibited high capacities over 150 mAh g-1 and good cycle performance at large charge-discharge current density of 5 mA cm-2 (ca. 1 A g-1). In this case, the heat treatment was effective process to improve the cycle performance.

Abstract: Composite materials of β-FeOOH particles and carbon powder were prepared by hydrolyzing of FeCl3+Ti(SO4)2 (aq.) in which carbon powder was dispersed. β-FeOOH formed in the presence of Ti(IV) ions became amorphous and/or low crystallinity. The composite materials prepared in the presence of Ti(IV) ions worked as lithium intercalation electrodes in nonaqueous electrolytes including lithium ions. The electrodes exhibited a good cycle performance at large charge-discharge current density over 5 mA cm-2 ( 4 A g-1 per weight of active material). The composite materials are one of the promising candidates as electrode materials for energy storage devices, such as hybrid electrochemical supercapacitor, that require high-power operations.

Abstract: Composite electrode material of crystalline b-FeOOH and carbon was prepared by hydrolyzing of FeCl3 (aq.) in which carbon powder with various specific surface areas was dispersed. Composite electrode material of b-FeOOH fine particles and Ketjen black (KB:specific surface area 1270 m2 g-1) of high specific surface area exhibited the high capacity over 250 mAh g-1 per b-FeOOH weight and good cycle performances at rapid charge-discharge current density over 5 mA cm-2 (ca. 5.0 A g-1 per b-FeOOH weight) in nonaqueous electrolytes including lithium ions. Composite electrode materials of crystalline b-FeOOH and carbon are one of the promising candidates as electrode materials for energy storage devices that high-power operations are required.