Halloysite nanotubes and Fe₃O₄ nanoparticles enhanced adsorption removal of heavy metal using electrospun membranes

Magnetic nonwovens had been strategically prepared by immobilizing halloysite (Hal) nanotubes and Fe₃O₄ nanoparticles on polyethylene oxide/chitosan (PEO/CS) composite fibers via electrospinning. TEM, XPS, XRD, FTIR, UV–vis DRS, BET, and VSM analyses of the adsorbents were used to determine their structure and performance. The effect of organic-inorganic hybridization provided the as-obtained adsorbents with uniform structure, superior pore structure, large specific surface area, and superparamagnetic properties. These nonwovens also exhibited high removal efficiency of different heavy metal ions (HMIs), and the adsorption capacity of cadmium, copper, lead and chrome onto the nonwoven was in order of Cr(VI) < Cd(II) < Cu(II) < Pb(II). The pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models were employed to analyze the kinetic data, which suggested the chemisorption was distinct but the intraparticle-diffusion was not significant. The anti-anion interference capability and reusability of membranes for the removal of different HMIs were also determined, which indicated that the nanofibrous adsorbents were widely adaptable and reusable. In addition, the composite membranes showed high antibacterial activity for E. coli and S. aureus. Thus, these proficient inorganic-materials-doped magnetic nonwovens are suitable to employ as a heavy metal adsorbents with salient removal capacity.