Adsorption of Cu(II) from aqueous solution by anatase mesoporous TiO2 nanofibers prepared via electrospinning

Anatase mesoporous titanium nanofibers (m-TiO2 NFs) have been synthesized from calcination of the as-spun TiO2/polyvinyl pyrrolidone (PVP)/pluronic123 (P123) composite nanofibers at 450 degrees C in air for 3 h. The structures and the physicochemical properties of m-TiO2 NFs are characterized by scanning electron microscopy, X-ray diffraction, nitrogen adsorption-desorption isotherm analysis, and determination point of zero charge, respectively. An investigation of Cu(II) adsorption onto m-TiO2 NFs has been studied in this research. The pH effect, adsorption kinetics, and adsorption isotherms are examined in batch experiments. Experimental data were analyzed using pseudo-first order and pseudo-second order kinetic models. It was found that adsorption kinetics were the best fitting by a pseudo-second order kinetic model. The optimum pH for Cu(II) adsorption was found to be 6.0. The equilibrium data were analyzed by the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models, which revealed that the Freundlich isotherm is the best-fit isotherm for the adsorption of Cu(II). Compared to the TiO2 NFs (regular anatase titanium nanofibers) in the same experimental conditions to elucidate the role of the mesoporous structure of m-TiO2 NFs, experimental results showed that the m-TiO2 NFs had a better adsorption capacity for Cu(II) due to its higher surface area. (C) 2011 Elsevier Inc. All rights reserved.