Facile Synthesis of Analcime (NaSi2AlO6·H2O) Nanoparticles Using Polyethylene Glycol 400 as an Organic Template for Effective Removal of Zn(II) and Cd(II) Ions from Aqueous Solutions

The scientific impact and novelty of the present work come from comparing the properties of analcime nanoparticles synthesized in the absence of polyethylene glycol 400 (abbreviated as AF) and in the presence of different volumes (3 mL (abbreviated as A3), 6 mL (abbreviated as A6), and 9 mL (abbreviated as A9)) of polyethylene glycol 400 as an organic structure template. The average crystallite size of the AF, A3, A6, and A9 samples is 150.83, 75.22, 47.64, and 87.58 nm, respectively. The BET surface area of the AF, A3, A6, and A9 samples is 17.61, 28.13, 58.24, and 23.77 m2/g, respectively. The FE-SEM images displayed that the A3 and A6 samples display a combination of spherical and polyhedral forms with mean diameters of 13.46 and 8.79 μm, respectively. The AF and A9 samples exhibit polyhedral forms with mean diameters of 20.36 and 19.03 μm, respectively. The maximum adsorption capacity of the AF, A3, A6, and A9 samples towards Zn(II) ions is 83.68, 115.61, 151.52, and 105.71 mg/g, respectively. The maximum adsorption capacity of the AF, A3, A6, and A9 samples towards Cd(II) ions is 59.95, 105.59, 134.23, and 93.19 mg/g, respectively. The removal of Zn(II) and Cd(II) ions by the AF, A3, A6, and A9 samples is chemical, spontaneous, and follows the Langmuir equilibrium isotherm and pseudo-second-order kinetic model. The synthesized adsorbents were regenerated using ethylenediaminetetraacetic acid tetrasodium salt dihydrate solution and have the ability to be used several times without significantly affecting their efficiency.