Magnetic nanocomposite cobalt-multiwalled carbon nanotube and adsorption kinetics of methylene blue using an ultrasonic batch

Abstract

Herein, cobalt (0) metals loaded on multiwalled carbon nanotube nanoadsorbents were synthesized by a straightforward ultrasonic technique, and the removal efficiency of cobalt (0) multiwalled carbon nanotube nanoadsorbents were evaluated in the adsorption of methylene blue at various experimental conduction in an ultrasonic bath. Nanoadsorbents amount, solution pH, ultrasonic power, methylene blue concentrations, temperature, and H2O2 concentrations were studied as experimental parameters in the study. The synthesized cobalt (0) multiwalled carbon nanotube nanoadsorbents were characterized using some advanced spectroscopic techniques. The adsorption mechanism of methylene blue using the as-synthesized nanoadsorbents was evaluated by investigating some kinetic models including intra-particles diffusion, the pseudo-first-order, and the second-order models. The experimental findings of methylene blue adsorption by cobalt multiwalled carbon nanotube was found to be compatible with the pseudo-second-order model. Additionally, some kinetic activation studies like Gibbs free energy, enthalpy, and activation energy for the methylene blue adsorption were investigated. The enthalpy of the process was found to be 25.29 kJ mol−1 that shows the adsorption process is endothermic. The maximum adsorption efficiency of the nanoadsorbents was found to be 1.04 × 10−3 mol g−1 (324.34 mg g−1). The comparisons of results to the previous studies revealed that the synthesized nanoparticles were found to be very effective for the removal of methylene blue from the aquatic mediums.