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 dio-xide(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@MnO₂nanofibers 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.