One step synthesis of carboxymethyl cellulose/graphene oxide composites for removal of copper ion from aqueous solution

Excessive heavy metal ions in the environment often have an impact on plant growth and human health. In this study, carboxymethyl cellulose/graphene oxide composites (CMC/GO) were prepared by a simple solution blending evaporation method to remove copper ions. The structure of CMC/GO was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Scanning electron microscope, Brunauer–Emmett–Teller, and X-rayphotoelectron spectroscopy. The results showed that the maximum adsorption capacity of the adsorbent CMC/GO reached 26.05 mg/g, when the pH of the solution was 5, the initial concentration of copper ions was 80 mg/L, and the dosage of the adsorbent was 0.4 g. The adsorption of copper ions onto CMC/GO is validated by the pseudo-second-order kinetics model (R = 0.99949), and the adsorption isotherm data was fitted well with the Langmuir isotherm (R = 0.99989). Thermodynamic data showed that the adsorption process of copper ions by composite CMC/GO is a spontaneous endothermic reaction (ΔG < 0, ΔH > 0). Moreover, the adsorbent showed better recyclability and the adsorption efficiency can still reach 85.0 % after 5 adsorption-desorption cycles.