Dongxue Yang,Lingfeng Li,Binling Chen,Shuxian Shi,Jun Nie,Guiping Ma
In order to improve the removal ability of chitosan (CS) to heavy metal ions , in this study, rich amino-functionalized CS electrospun membranes have been prepared. During the efficient synthesis, poly (glycidyl methacrylate) (PGMA) and polyethylenimine (PEI) were sequentially grafted on the surface of CS electrospun membrane. The success of introduction of amino-group on the CS were confirmed by X-ray diffractometer (XRD), attenuated total reflection-fourier transform infrared (ATR-FTIR), and X-ray photoelectron spectroscopy (XPS). The ability of remove heavy metal ions (Cr(VI), Cu(II) and Co(II)) of the as-prepared membrane (CS-PGMA-PEI) was investigated. The adsorption equilibrium of the heavy metal ion solutions was rapidly established in 60 min. Adsorption kinetics analysis reveals that the adsorption process of CS-PGMA-PEI electrospun membrane was dominated by a Pseudo-second-order model. Its adsorption isotherm can be described by the Langmuir model. The maximum adsorption capacities calculated by Langmuir model were 138.96, 69.27 and 68.31 mg g −1 for Cr(VI), Cu(II) and Co(II), respectively. The adsorption ability of CS-PGMA-PEI electrospun membrane toward metal ions was found in an order of Cr(VI) > Cu(II) > Co(II). CS-PGMA-PEI membrane also exhibited a good reproducibility and stability. Our study may provide a way to synthesize membranes for water purification .
A highly efficient and stable Au–Cu/hydroxyapatite (HAP, Ca10(PO4)6(OH)2) catalyst was reported. HAP was prepared through a deposition–precipitation method. Au–Cu/HAP catalysts were obtained by a two-step impregnation approach. The samples were characterized by XRD, TEM, SEM, UV-Vis, ICP, XPS, H2-TPR, and O2-TPD. CO oxidation reaction was carried out to evaluate the catalytic performance of samples. TEM and UV-Vis results showed that the metallic particles supported on Au–Cu/HAP were smaller than those on Au/HAP, and they were highly dispersed on the HAP support. Patterns of XPS revealed that CuO nanoparticles were formed in the Cu/HAP catalyst, while CuO and Cu2O species coexisted in Au–Cu/HAP catalyst. Based on the O2-TPD data, the addition of copper to Au/HAP gave rise to more new O2 adsorption sites and bigger O2 adsorption capacity. The catalysis results indicated that the Au–Cu/HAP was capable of obtaining higher efficiency and stability compared with Au/HAP and Cu/HAP for CO oxidation. It was likely that the synergistic interaction between gold and CuOx phase created the most active sites on Au–Cu/HAP and was responsible for the enhanced activity and stability in comparison with Au/HAP and Cu/HAP.
危险品化学品经营许可证（带存储）