Korean Journal of Chemical Engineering, Vol.39, No.11, 3155-3164, November, 2022
Efficient dual adsorption of eosinY and methylene blue from aqueous solution using nanocomposite of graphene oxide nanosheets and ZnO nanospheres
A versatile graphene oxide nanosheets-ZnO nanospheres nanocomposite was synthesized for removal of dyes via adsorption process and characterized by various techniques, such as X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and zeta potential (ZP) analyzer. The synthesized nanocomposite (NCs) was utilized as an efficient adsorbent for the removal of anionic dye eosin y (EY) as well as cationic dye methylene blue (MB) from aqueous solutions. The kinetics of adsorption was studied by pseudo-first and pseudosecond- order kinetics and the adsorption data was well in agreement with the pseudo-second-order model. The R2 values of 0.9971 and 0.9839 of the second order for EY and MB, respectively, were greater than that of the first order. To calculate the most suitable isotherm model for adsorption, the Freundlich and Langmuir isotherms were applied and the data for both dyes fitted well with the Langmuir model. The maximum adsorption capacities obtained from Langmuir isotherm for EY and MB were 555.55 and 250mg/g, respectively. Remarkably, 3.0mg/13mL of nanocomposite adsorbed 0.1mg/mL of EY and 0.04mg/mL of MB in the very short time of 10 and 15minutes, respectively. The high adsorption efficiency of GO/ZnO NCs suggests that they may be a useful adsorbent for the purification of industrial wastewater.