Polydopamine coating assisted synthesis of MnO2 loaded inorganic/organic composite electrospun fiber adsorbent for efficient removal of Pb2+ from water

Polydopamine (PDA) and MnO 2 have been proven to be promising adsorbents to capture Pb 2+ from wastewater. In this study, MnO 2 was in-situ loaded onto flexible electrospun polyacrylonitrile (PAN) fibers by the assistance of polydopamine coating (MnO 2 /PDA/PAN fibers) and the as-obtained MnO 2 /PDA/PAN fibers were utilized for the removal of Pb 2+ from water. The structure and chemical composition of MnO 2 /PDA/PAN fibers were characterized in detail. The results indicated that the PDA coating onto PAN fibers can’t be neglected for loading MnO 2 . This preparation of MnO 2 /PDA/PAN fibers could avoid the agglomeration of MnO 2 particles and make the adsorbent separate easily from the adsorption solution. The adsorption experiments showed that the adsorption process toward Pb 2+ by MnO 2 /PDA/PAN fibers followed pseudo-second-order model and Langmuir isotherm model. In comparison with PDA/PAN fibers and MnO 2 /PAN fibers, MnO 2 /PDA/PAN fibers showed higher Pb 2+ adsorption capacity. The maximum adsorption capacity calculated from Langmuir model was 185.19 mg/g, which is higher than most of the reported PDA or MnO 2 based Pb 2+ adsorbents. The adsorption toward Pb 2+ by MnO 2 /PDA/PAN fibers still maintained stability after five adsorption/desorption cycles. In addition, the fiber adsorbent could also adsorb Pb 2+ from real industrial effluent with removal efficiency above 95%. This work indicates that MnO 2 /PDA/PAN fibers have great potential to be used as effective adsorbents for practical Pb 2+ removal.