The bio-inspired polydopamine/reduced graphene oxide (PDA/RGO) composites were prepared by grafting dopamine with graphene oxide nanosheets. The structure and surface properties of the as-synthesized composites were characterized by X-ray diffraction (XRD)

Fourier-transformed infrared spectroscopy (FTIR)

field-emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS). The adsorption behavior and properties of aqueous Fe(Ⅲ) on the PDA/RGO composites were also investigated. The effects of pH

adsorbent amounts

adsorption time

initial concentration of Fe(Ⅲ) and temperature on adsorption properties were investigated in details. From these characterization results

it was indicated that dopamine and graphene oxide could be successfully produced to PDA/RGO composites via the bio-inspired self-assembly. The PDA/RGO composites showed high adsorption performance for aqueous Fe(Ⅲ). The maximum adsorption capacity of 59.1 mg·g-1 for Fe(Ⅲ) on the PDA/RGO composites was obtained at 293 K and pH of 2. The adsorption isotherm of Fe(Ⅲ) on the PDA/RGO composites could be described better with Freundlich equation model than Langmuir model

and the pseudo-second-order kinetics equation fitted well with the adsorption data. The adsorption process for Fe(Ⅲ) on the PDA/RGO composites was an exothermic and spontaneous

exhibiting heterogeneous adsorption characteristics. As a kind of new adsorption materials

the PDA/RGO composites will have potential application in wastewater treatment containing metals such as Fe(Ⅲ).