Study on the nanocomposites of polyaniline and Zn doped Fe3O4 using for arsenic absorption in water

The polyaniline/Fe_2.9Zn_0.1O₄ (PANI/Fe_2.9Zn_0.1O₄) nanoparticles with different mass ratios were synthesized by both co-precipitation and in situ polymerization methods. The FT-IR spectra and DTA analyses showed the involvement of PANI in the nanocomposite samples. The grain size of samples measured by SEM ranges from 25 to 40 nm. The magnetization of samples at 300 K, H = 11000 Oe decreased from 65 to 43 emu g⁻¹ as PANI/Fe_2.9Zn_0.1O₄ mass ratio increased from 9% to 40%. At pH 7 and 300 K, the maximum arsenic (III) adsorption capacities of sample S₁ (mass ratio of 9%) q_max = 43.48 mg g⁻¹ was higher than that of others and Fe₃O₄. Additionally, the substitution of Fe²⁺ ions by Zn²⁺ ions and the presence of PANI in samples contributed to improving the magnetic and chemical stability of samples over time. Furthermore, these materials could be reused after desorption in a solution at pH 14.