Simple production and characterization of ZnO/MgO nanocomposite as a highly effective adsorbent for eliminating congo red dye from water-based solutions

Congo red dye can result in dangerous effects on the human health such as skin and eye irritation, digestive system troubles, somnolence, blood clotting, and breathing disorders. Therefore, ZnO/MgO nanocomposite was simply generated by the Pechini sol-gel technique in the presence of ethylene glycol and tartaric acid as a crosslinker and chelating agent, respectively. The ZnO/MgO nanocomposite was utilized for the prompt elimination of congo red dye from water-based solutions. The BET surface area and mean crystal size of the ZnO/MgO nanocomposite are 58.72 m2/g and 87.56 nm, respectively. SEM analysis revealed that the ZnO/MgO nanocomposite is composed of semi-spherical particles with a mean diameter of approximately 372.77 nm. The ZnO/ MgO nanocomposite exhibits a maximum adsorption capacity of 317.46 mg/g for congo red dye. The optimal conditions for achieving the highest removal percentage of congo red dye by the ZnO/MgO nanocomposite are found at pH 2, a contact time of 90 min, and a temperature of 298 K. Additionally, the elimination process of congo red dye on the ZnO/MgO nanocomposite is spontaneous, chemical, and exothermic. The Langmuir isotherm, along with the pseudo-second-order model, provides a more satisfactory illustration of the elimination of congo red dye by the ZnO/MgO nanocomposite. Moreover, the ZnO/MgO nanocomposite demonstrates the ability to be reused multiple times for congo red dye removal without compromising its efficiency.