Synthesis of copper oxide nanowires-activated carbon (AC@CuO-NWs) and applied for removal methylene blue from aqueous solution: kinetics, isotherms, and thermodynamics

Abstract

In the present study, we focused on the synthesis of copper oxide nanowires decorated on activated carbon (AC@CuO-NWs) for the removal of methylene blue (MB) from aqueous solutions. The AC@CuO-NWs nanocomposite is synthesized via simple precipitation method and characterized by using various techniques which includes scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), and X-rays diffraction analysis (XRD). XRD results confirmed the monoclinic structure of CuO-NWs with the average crystalline size ~ 17.48 nm. The SEM images indicated the wire-like structure and EDX analysis confirms the CuO nanomaterial. The SEM image shows that nanowires are agglomerated to form like flower shape. The batch adsorption experiments were optimized using various parameters such as pH, contact time, initial dye concentration, kinetic and isotherm studies. The results showed that the adsorption processes were well fitted with the PSO model. The adsorption equilibrium experimental data fitted to the Langmuir models with a maximum adsorption capacity of 141.73 mg/g at 328 K. The thermodynamics results reveal that the adsorption processes are spontaneous and endothermic in nature. The high negative value of ΔG° and a low value of ΔH° show the feasibility with physisorption and endothermic nature of the adsorption process. The acquire results indicating that AC@CuO-NWs based nanocomposite is having the high MB adsorption capacity in short equilibrium period and good substitute as the low-cost adsorbent in wastewater treatment. The synthesis of AC@CuO-NWs nanocomposite material is simple, easy and scale-up that might be efficiently used in water treatment technologies.