Prepared PANI@nano hollow carbon sphere adsorbents with lappaceum shell like structure for high efficiency removal of hexavalent chromium

Abstract

Herein, the novel polyaniline@nano hollow carbon sphere (PANI@NHCS) adsorbents with different mass of NHCS were prepared by in-situ polymerization method. The microstructure of obtained PANI@NHCS-10, PANI@NHCS-20, PANI@NHCS-30 and PANI@NHCS-40 samples were observed through both scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which showed that the PANI@NHCS-30 possessed hollow structure like lappaceum shell. Then, the performance of obtained PANI@NHCS-30 was studied for removing hexavalent chromium (Cr(VI)) from waste water. With the help of unique hollow structure and reduction ability of PANI@NHCS-30, the Cr(VI) was fleetly adsorbed and then reduced to less toxic Cr(III). The maximum adsorption capacity was 250.0 mg/g for PANI@NHCS-30 under the optimal condition. Moreover, the effects of initial Cr(VI) concentration, solution pH and different ions on the adsorption performance were investigated in detail. Importantly, the PANI@NHCS-30 still shows superb adsorption ability after five cycles, which suggests its satisfactory reusability ability. The accumulated data revealed the crucial role of PANI and hollow structure co-promoting effect on Cr(VI) reduction reactions over PANI@NHCS-30, which could be applied to the practical use.