Preparation of α-Fe₂O₃/polyacrylonitrile nanofiber mat as an effective lead adsorbent

Abstract

α-Fe2O3 nanoparticle has been widely used in water purification because of its effective adsorption performance. However, aggregation and difficulty in separation limit its practical application. Herein, we presented a polyacrylonitrile (PAN) nanofiber mat decorated with α-Fe2O3 as adsorbent for effective removal of Pb 2+ from contaminated water, which can solve the above problems easily. The α-Fe2O3/PAN nanofiber mats were prepared via electrospinning followed by a facile hydrothermal method and characterized by SEM, HRTEM, FTIR and XRD. We demonstrated the formation mechanism of α-Fe2O3 anchored on PAN nanofiber surface consists of the adsorption of iron ions on the surface of PAN, and then the α-Fe2O3 nucleation and growth. The pH value of FeCl3 solution has a great impact on the formation process of α-Fe2O3/PAN nanofiber mat, which lead to the variation of morphology and the quantity of the coating coverage. When the pH value was 2.4, polyhedral particles were coated on PAN nanofibers uniformly and the optimized α-Fe2O3/PAN nanofiber mat was obtained. Controlled experiments were carried out to quantify the adsorption capacities of different samples and adsorption kinetics. The isotherm data from our experiments fitted well to the Langmuir model and the adsorption process can be described using the pseudo-second-model. Finally, the adsorption mechanism for Pb 2+ was investigated and the results revealed that ion exchange between proton of surface hydroxyl groups and Pb 2+ was accounted for the adsorption. Fig. 6 The effect of contact time on Pb 2+ adsorption capacity with different initial concentration (a), SEM image of α-Fe2O3/PAN (S2.4) after adsorption (b), the fitting results using pseudo first order (c), and pseudo second order (d) kinetic model.

De Novo Ion-Exchange Membranes Based on Nanofibers

“…The inorganic nanoparticles possessing ion-exchange properties are attractive to be used for heavy metal removal and the NF carriers can circumvent aggregation and increase their active sites. There have been reports on the incorporation of metal oxide nanoparticles [ 101 , 102 , 103 , 104 ], zeolite nanoparticles [ 105 ], and hydroxyapatite nanoparticles (Hap NP) [ 106 ] in polymer NF membranes by electrospinning for heavy metal adsorption. For example, Tran et al incorporated zeolite nanoparticles into electrospun cellulose acetate fibers to create free-standing IEX-NF membranes [ 107 ].…”

Nanofibers as novel platform for high‐functional ion exchangers

“…Chang et al . studied poly(acrylonitrile) nanofibrous mats decorated with α‐Fe 2 O 3 as an effective lead adsorbent . It is suggested that the ion exchange between the Pb 2+ and protons of the hydroxyl bonded on the surface of the iron oxide accounted for the adsorption.…”

Microcystis aeruginosa Synergistically Facilitate the Photocatalytic Degradation of Tetracycline Hydrochloride and Cr(VI) on PAN/TiO2/Ag Nanofiber Mats

“…Polyacrylonitrile (PAN)-based hybrid nanofibers are water insoluble and can be easily recovered from solution. Moreover, they have highly specific surface areas and functional nanoparticles; thus, these merits enhance their potential application [16,17]. In this work, we used a one-step method to prepare PAN/TiO 2 /Ag nanofibers (PAN/TiO 2 /Ag NF), and solvents such as N,N-dimethylformamide (DMF) served as electrospinning reducing agents for the synthesis of metallic Ag nanoparticles (AgNPs) [18].…”