Investigation of malachite green removal using graphene oxide-zinc oxide composite from aqueous solution: synthesis, characterization and application

Chemically synthesized graphene oxide-zinc oxide (GO-ZnO) composite was used as an adsorbent to remove malachite green (MG) from the aqueous solution. It was used due to its high thermal stabil-ity, high surface area and porous structure which are favourable for adsorption study. Several steps were conducted for the entire research study. GO-ZnO composite was synthesized as an effective adsorbent material. A batch experiment was carried out by using the prepared GO-ZnO adsorbent materials to remove the MG from the aqueous solution. The physicochemical parameters such as pH, contact time, initial concentration and dosage of adsorbent were optimized to get the highest removal efficiency of MG. The maximum removal efficiency of GO-ZnO adsorbent for MG dye was found to be 94% at pH 8. Characterization was carried out to identify the morphology, crystallin-ity and chemical compositions. The GO-ZnO adsorbent was characterized by using scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and Fourier-transform infrared spectroscopy.