Synthesis of modified PANI/CQDs nanocomposite by dimethylgyloxime for removal of Ni (II) from aqueous solution

Polyaniline/carbon quantum dots (PANI/CQDs) nanocomposites were synthesized by simple interfacial poly-merizations of aniline followed by adding different contents of carbon quantum dots (1,10 wt. %) to the poly-aniline. The resulting (PANI/CQDs) nanocomposites were impregnated by dimethylgyloxime (DMG) and used as adsorbent to remove nickel ions (Ni II) from aquous solution. The nanocomposites were characterized using different techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR). A highly ordered crystalline nanosheets structure of PANI decorated by CQDs completely coated with DMG is obtained. The developed PANI/CQDs/DMG nanocomposite using 1,10 wt. % of CQDs have a high adsorption capacity of 290.3 and 245 mg/g, respectively. Several effects were studied to optimize the removal efficiency. Thermodynamic parameters such as entropy changes, enthalpy changes, and Gibbs free energy were evaluated. The adsorption kinetics of Ni (II) ions onto PANI/10-CQDs/DMG follows the second-order kinetic model. The adsorption isotherm models followed Langmuir isotherm. The developed promised nanocomposite is cheap, has high adsorption capacity, and reusable.

Automated summary

The study synthesized PANI/CQDs nanocomposites with high adsorption capacity for nickel ions. Various aspects were studied, including thermodynamic parameters, kinetic models, and adsorption isotherms, to optimize and evaluate the performance of the developed nanocomposite. The nanocomposite showed promising potential as a cheap, high-capacity, and reusable adsorbent.