ZnO Impregnated Graphene Silica Composite to Enhance Cr(VI) Adsorption: Batch Studies

Abstract Hexavalent chromium [Cr(VI)] is a profoundly poisonous heavy metal due to its significant mobility across cell membranes as HCrO 4 − and CrO 4 2- ions. There is a limited amount of research on the effectiveness of metal oxide impregnated graphene silica composite (GSC) as adsorbents for treating [Cr(VI)]. However, the existing studies indicate that these composites are very efficient. The project involved synthesizing a new type of adsorbent by impregnating zinc oxide (ZnO) particles onto a composite material of graphene and silica. This was achieved using the co-precipitation method. The findings revealed that the highest level of Cr (VI) removal (97%) is achieved at basic, a contact period of 45 minutes. The Langmuir isotherm had the highest degree of fit, suggesting a uniform and chemical adsorption process with the highest possible adsorption capacity of 142 mg/g. The application of ZnO on GSC improves the motion of Cr(VI) in the composite, resulting in an increase in both the adsorption capacity and adsorption kinetics. The findings of this investigation show that the ZnO/GSC composite is a very effective and versatile adsorbent for treating wastewater, highlighting its new and reusable properties.