A novel hybrid nanocomposite, polypyrrole nanoparticles (PPy) anchored on the graphene/silica nanosheets with the high specific surface area (polypyrrole-graphene/silica, GS-PPy), was synthesized by a facile in situ polymerization and shows great potential to remove hexavalent chromium [Cr(VI)] in aqueous solutions. Characterizations by XRD, TEM, SEM, BET, FT-IR and XPS, have confirmed that the PPy nanoparticles were well-distributed on the surface of GS nanosheets. The effects of pH, contact time, the concentration of Cr(VI), temperature, coexisting ions and the number of adsorption-desorption cycles were studied. The maximum adsorption capacity of the GS-PPy for Cr(VI) was 429.2 mg g⁻¹ at 298 K at pH 2, which was much higher than PPy nanoparticles and other related materials. The adsorption data fitted to the pseudo-second-order model and Langmuir isotherm model. The removal mechanism involved in electrostatic attraction, ion exchange and reduction process that partial adsorbed Cr(VI) was reduced to Cr(III). And Cr(III) was still retained on the surface of GS-PPy. The GS-PPy nanocomposite will be a potential candidate for the removal of Cr(VI) from the industrial waste water.

一种新型的杂化纳米复合材料，聚吡咯纳米颗粒（PPy）固定在具有高比表面积的石墨烯/二氧化硅纳米片（聚吡咯-石墨烯/二氧化硅，GS-PPy）上，通过简便的原位聚合反应合成，显示出去除六价态的巨大潜力水溶液中的铬[Cr（VI）]。通过XRD，TEM，SEM，BET，FT-IR和XPS进行表征已证实PPy纳米颗粒在GS纳米片的表面上分布良好。研究了pH，接触时间，Cr（VI）浓度，温度，共存离子和吸附-解吸循环次数的影响。GS-PPy对Cr（VI）的最大吸附容量为429.2 mg g ^-1在298 K的pH值为2的条件下，它远高于PPy纳米颗粒和其他相关材料。吸附数据拟合拟二阶模型和Langmuir等温模型。去除机理涉及静电吸附，离子交换和还原过程，该过程将部分吸附的Cr（VI）还原为Cr（III）。Cr（III）仍然保留在GS-PPy的表面上。GS-PPy纳米复合材料将是从工业废水中去除六价铬的潜在候选者。