Hybrid hydroxyapatite/graphene oxide composites materials synthesized from eggshell for adsorption of Cr(VI) in aqueous solution

In this work, hydroxyapatite/graphene oxide hybrid composites (HAP/GO) were prepared from eggshell by solvothermal method, which was mainly used as adsorbents for Cr(VI) removal in wastewater. The effect of graphene oxide (GO) on the structure and removal efficiency of HAP/ GO was discussed. The results showed that the Cr(VI) removal of HAP/GO10% can reach more than 90% within 1 h, and the adsorption conforms to the first-order kinetics. It was found that the addi-tion of GO changed the pore size distribution of HAP/GO and improved Cr(VI) removal. It can be concluded that the swelling of GO in aqueous solution leads to an increase in the interaction between the dissociated carboxyl groups and Cr(VI), thereby improving the adsorption efficiency.