Preparation And Application Of Functional Nanomaterials Base On The Hydrothermal Process Of Glucose

Development and design of “green” synthetic route for high performancenanomaterials are of great significance to engineering application and environmentalprotection. In this article, nano-sized carbon spheres, magnetice materials of pureFe₃O₄particles and Fe₃O₄/C composites with core-shell structure were synthesized byhydrothermal method. During the hydrothermal reaction process, glucose and waterwere used as the raw material and the solvent, respectively. Morphology, structure,phase composition, magnetic properties and intermediate products of the sampleswere characterized by scanning electron microscopy （SEM）, transmission electronmicroscopy （TEM）, X-ray photoelectron spectroscopy （XPS）, laser micro-Ramanspectrometer （Raman）, elemental analyzer （EA）， Fourier transform infraredspectrometer （FTIR）, TG analyzer （TGA）, vibrating sample magnetometer （VSM） andhigh performance liquid chromatography （HPLC）. Based on the Fe₃O₄/C composites,magnetic catalytic material of Ag-Fe₃O₄/C was fabricated by in-situ reduction method,and its catalytic performance was investigated by UV-Visible spectrophotometer（UV-Vis） in the catalytic degradation of the Rhodamine B （RhB） process.The results showed that the surface of the carbon spheres prepared by thehydrothermal method were rich in hydrophilic and functional groups. The carbonspheres had a diameter range of90nm¹1μm. The effects of the experimentparameters, such as reaction time, temperature, glucose concentration and the initialpH value of the hydrothermal reaction system were were discussed in the experimentprocess. Pure Fe₃O₄particles without coating and Fe₃O₄/C composites with acore-shell structure were synthesized in the hydrothermal reaction system whichcontained glucose and iron chloride. Sodium hydroxide （NaOH） and sodium acetate（NaAc） were used as the precipitant, respectively. The sizes of the pure Fe₃O₄and theFe₃O₄/C composites were varied from10nm to150nm. The interaction between theraw materials and the distinction of the formation process were both studied. Besidesof the magnetic properties, it could be found that the Fe₃O₄/C composites alsoretained wealth of functional groups from the hydrothermal carbonization process ofglucose. And this feature was subsequently used in the preparation process of theAg-Fe₃O₄/C materials. Silver nanoparticles were loaded on the carbon layer of the Fe₃O₄/C composites via an in-situ reduction process. This reduction process did notintroduce any other reducing agents, and it was the functional groups on the surfaceplayed the role of reducing the Tollen’s reagent to silver. The carbon layer wassandwiched between the magnetite core and silver nanoparticles in the Ag-Fe₃O₄/Cmaterials. Such a configuration allowed the catalyst particles were accessible to thereacting species outside, and at the same time the magnetite core could be protectedfrom oxidation or aggregation. In the catalytic decoloration of Rhodamine B （RhB）process, both the catalysis and the stability of this structure were excellent performed.