Formation Mechanism of α-Fe2O3 Nanotubes via Electrospinning and Their Adsorption Characteristics of BSA and DNA

The α-Fe₂O₃ nanotubes with diameters of 400–700 nm have been prepared via the sol–gel assisted electrospinning and subsequent one-step heat treatment with ferric nitrate, ethanol and poly(vinyl pyrrolidone) as starting regents. The resultant α-Fe₂O₃ nanotubes were characterized by XRD, SEM, TEM, and VSM techniques. The hollow structure is mainly influenced by the water content in the gel precursor and the heating rate, and the hollow formation mechanism of α-Fe₂O₃ nanotubes is discussed. Adsorption of BSA onto the as-prepared α-Fe₂O₃ nanotubes exhibits a good capacity of 56.5 mg/g with the initial BSA concentration of 1.0 mg/mL, which demonstrates their feasibility in delivery of biomacromolecules. Subsequently, the adsorption characteristics of DNA onto the α-Fe₂O₃ nanotubes were investigated, and the adsorbance of DNA can achieve a maximum value of 4.19 μg/g when the initial DNA concentration is 50 μg/mL. The adsorption process of DNA onto α-Fe₂O₃ nanotubes can be described well by the pseudo-first-order kinetic model at room temperature according to the correlation coefficient R ² = 0.9978.