A Novel Hollow Carbon@MnO2 Electrospun Nanofiber Adsorbent for Efficient Removal of Pb2+ in Wastewater

Lead ion(Pb2+) is one of the most hazardous heavy metal ions in aquatic environments. Carbon materials and manganese dioxide(MnO2) have been shown to be prospective adsorbents to cope with the lead pollution. In this study, a novel hollow carbon@MnO2 composite nanofiber adsorbent was prepared by the combination of electrospinning and carbonization. The PAN nanofiber membrane is subjected to a pre-oxidation and carbonization process, and then the obtained carbon nanofibers react with KMnO4 solution during the hydrothermal process to develop the hollow carbon@MnO2 nanofibers. The hollow carbon@MnO2 nanofibers displayed a higher adsorption capacity of Pb2+ than carbon and MnO2/PDA/PAN nanofibers. The maximum adsorption capacity toward Pb2+ by hollow carbon@MnO2 nanofibers was 460.83 mg/g. After 5 adsorption-desorption cycles, the carbon@MnO2 nanofibers had a good recyclability and the removal efficiency remained 81.47%. Moreover, the removal efficiency of the hollow composite nanofibers for Pb2+ from real wastewater could reach 94.37%. This work shows a strategy for synthetics of the hollow carbon@MnO2 nanofibers, which exhibits a promising potential in actual wastewater treatment.