Preparation and characterization of chitosan/graphene oxide composites for the adsorption of Au(III) and Pd(II)

► Chitosan/graphene oxide composites were prepared and used for the adsorption of Au(III) and Pd(II). ► Atomic adsorption spectrophotometer (FAAS) was applied to determine the concentrations of metal ions. ► Chitosan/graphene oxide composite with 5 wt% GO was found owning the largest adsorption capacity. ► Due to the addition of GO into chitosan, the composites can be used in a larger pH range.