UiO-66 derived N-doped carbon nanoparticles coated by PANI for simultaneous adsorption and reduction of hexavalent chromium from waste water

Recently, metal organic frameworks (MOFs) have been regarded as a type of uniformly and stably precursor and efficient self-sacrificial template to prepare hierarchical porous carbon related nano-structured functional materials. Herein, we report the use of the zirconium MOFs (UiO-66) as a precursor to prepare N-doped carbon nanoparticles (NC) with high specific surface area (1609.1 m(2)/g) by direct carbonization and etching processes. Then, polyaniline (PANI) was growth on the NC by in-situ polymerization, showing a superb efficiency and stability for hexavalent chromium (Cr(VI)) removal. Due to the synergistic effect of adsorption and reduction of the obtained PANI@NC nanocomposites, the maximum adsorption capacity was 198.04 mg/g. The effects of different adsorbents, pH, adsorbent dosage, co-existing ions, concentration of Cr(VI) were studied on the Cr(VI) adsorption. The kinetics of adsorption of Cr(VI) followed the Pseudo-second-order model and the adsorption isotherm data fitted well to the Langmuir isothermal model. Importantly, excellent stability of PANI@NC nanocomposites was demonstrated after five cycles. The results of this research indicate that PANI@NC nanocomposites were the promising adsorbent for removal of Cr(VI) from waste water.