Easy-handling bamboo-like polypyrrole nanofibrous mats with high adsorption capacity for hexavalent chromium removal.

Development of highly efficient and easy-handling absorbents for heavy metals removal is desirable for the remediation of our existing aquatic system. Herein, we demonstrated the novel bamboo-like polypyrrole nanofibrous mats for the removal of highly toxic hexavalent chromium (Cr(VI)) from aqueous solution. To achieve this target, the V2O5 nanofibrous templates were prepared via non-emulsion electrospinning technique and calcination, followed by in-situ polymerization of pyrrole. Benefiting from the special porous structure, high surface area and abundant adsorption active sites, the resulting bamboo-like polypyrrole nanofibrous mats exhibited a high Cr(VI) adsorption capacity up to 961.5 mg g-1 at room temperature, which can be well maintained for five adsorption/desorption cycles. The adsorption capacity for Cr(VI) can be enhanced with the decrease of pH and adsorption process belonged to the pseudo-second-order model. Furthermore, the adsorption isotherms of bamboo-like polypyrrole nanofibrous mats fitted the Langmuir isotherm model, and the adsorption mechanism of electrostatic attraction between bamboo-like polypyrrole nanofibers and Cr(VI) was presented. More importantly, the flexible and integrated bamboo-like polypyrrole nanofibrous membrane allowed easy handling during application, which is potentially used for heavy metal removal from aqueous solution.