Polyindole was synthesized by chemical oxidation using ferric chloride anhydrous as oxidant.Polyindole nanofibers have been successfully prepared by using electrospinning method by dissolving polyindole in acetonitrile.The heavy metal uptake performance of the polyindole nanofibers was presented by adsorption of Cd(Ⅱ) ions from aqueous solution.FTIR and NMR spectra confirm that the polymerization of indole happens at C2

C3 positions of indole unit.Electrospun polyindole nanofibers exhibit cylindrical

uniform

bead-free and random orientation observed by SEM and TEM.The average diameter of the electrospun polyindole nanofibers is about 145 nm and the BET specific surface area is 73.45 m2/g.Electrospun polyindole nanofibers show good adsorption properties for Cd(Ⅱ) ions from aqueous solution.The equilibrium adsorption capacity is about 140.36 mg/g reached at pH 6 after 50 min.The adsorption isotherm data fit well the Freundlich isothermal model.The kinetic process of Cd(Ⅱ) adsorption by polyindole nanofiber is found to fit the pseudo-second order rate equation.Desorption results show that the adsorption capacity can retain 100.67 mg/g (up to 71%) after 10 times usage

which indicates that the polyindole nanofibers could be suitable for potential applications in water treatment for the removal of Cd(Ⅱ) ion as a nano-adsorbent.