Chitosan nanofibers functionalized by TiO2 nanoparticles for the removal of heavy metal ions

TLDR: In this paper, the chitosan/TiO 2 composite nanofibrous adsorbents were developed by two techniques including TiO 2 nanoparticles coated chitosa-nibers (coating method) and electrospinning of chitosi-nigram solutions (entrapped method) for the removal of Pb (II) and Cu(II) ions in a batch system.

Abstract: The chitosan/TiO 2 composite nanofibrous adsorbents were developed by two techniques including TiO 2 nanoparticles coated chitosan nanofibers (coating method) and electrospinning of chitosan/TiO 2 solutions (entrapped method). The potential of prepared nanofibers was investigated for the removal of Pb (II) and Cu (II) ions in a batch system. The nanofibers were characterized by SEM, FTIR and BET analysis. Kinetic and equilibrium studies showed that the experimental data of Pb (II) and Cu (II) ions were best described by pseudo-first-order and Redlich–Peterson isotherm models using the both chitosan/TiO 2 nanofibers. The maximum adsorption capacities of Cu (II) and Pb (II) ions using entrapped and coating methods were found to be 710.3, 579.1 and 526.5, 475.5 mg/g at equilibrium time of 30 min and 45  ° C, respectively. The reusability studies indicated that the chitosan/TiO 2 nanofibers prepared by entrapped method could be reused frequently without significant loss in adsorption performance after five adsorption/desorption cycles. Whereas, lower than 60% of total adsorption in first cycle took place for metal ions sorption using nanofibers prepared by coating method. The sorption studies of metal ions in a binary system revealed that the selectivity of metal sorption using chitosan/TiO 2 nanofibrous adsorbent was in order of Cu (II) > Pb (II).