Biomimetic Synthesis Of Function Materials Using Biomolecule As Temple And Their Properties

A large amout of industrial wastewater emerges during the industry production process.Among the industrial wastewater,heavy metal wastewater and dye wastewater do a lot of harm to the surrounding environments and human health for their toxicity.Therefore,removal of heavy metal ions or dyes from the wastewater has been taking great importance.In this paper,SiO2 microspheres, Hybrid SiO2 microspheres, flake-like P-MnO2,Pb2+-imprinted hybrid film were synthesized using biomolecule as temple,respectively.The properties of the as-obtained materials were also studied in this paper.SiO2 microspheres were biomimetic synthesized using cystine as a template.Field emission scanning electron microscope(SEM),Fourier transform infrared spectrograph (IR), Thermogravimetric Analysis(TGA) and X-ray diffractometer(XRD) techniques were used to characterize the as-obtained samples.SEM and IR results indicated that SiO2 microspheres were synthesized through a two-step process.Hybrid SiO2 microspheres which contained lots of -NH2 and -Si-OH formed under the function of the cystine template;then the SiO2 microspheres were obtained after removing the template by calcining at 600℃.TGA results showed that the as-obtained SiO2 microspheres exhibited better thermal stability.XRD pattern indicated that the as-obtained SiO2 microspheres were amorphous.The synthesizing mechanism of the SiO2 microspheres was also explored.The adsorption of Pb2+ from aqueous solution was investigated using Hybrid SiO2 microspheres as the adsorbent.Effects of the parameters such as pH, adsorption time,initial concentration of Pb2+ and temperature were studied by batch experiments.pH,initial concentration of Pb and temperature were optimized by Response Surface Method.The experimental data of kinetics fitted pseudo-second order equations well.Equilibrium could be well described by linear Langmuir model better than linear Freundlich model.The optimum condition was pH4.2,initial concentration of Pb2+ 86.7mg/L, temperature60℃.Under this condition,the theoretical adsorption efficiency was 88.2%.Flake-likeβ-MnO2 were biomimetic synthesized using L-Tyrosine as a template.Catalytic activity of the as-obtained Flake-likeβ-MnO2 on oxidative degradation of methyl orange was studied.Effects of various parameters including reaction time,β-MnO2 dosage, H2O2,initial concentration of methyl orange and pH were investigated,respectively.β-MnO2 dosage,initial concentration of methyl orange and pH were optimized by Response Surface Method.The result indicated the optimum condition wasβ-MnO2 dosage25.2mg,initial concentration of methyl orange9.1mg/L,pH4.0.Under this condition,the theoretical degradation efficiency is 96.93%.Pb2+-imprinted hybrid film(LIHF) was synthesized using chitosan as a template.X-ray photoelectron spectroscopy(XPS) was used to characterize the as-obtained samples.The selectivity of LIHF was studied via competitive adsorption experiment.The LIHF showed higher selectivity to Pb2+ than Cu2+ and Zn2+ in aqueous solution.XPS results indicated that the -NH2 and the Pb2+ were concerned for coordination.The mechanism of recognition of Pb2+ with LIHF was also explored.