Fabrication Of Functionalized Magnetic Nano Carbon Materials And Their Applications In Removal And Analysis Of Environmental Pollutants

This dissertation focuses on the fabrication of functionalized magnetic nano carbon materials and their application in removal and analysis of environmental pollutants. It consists of the following four parts.In the first part, we describe the properties, functionalization of the magnetic nanomaterials and their application status in the field of removal and analysis of environmental pollutants. In addition, we introduce the fabrication of magnetic mesoporous carbon materials.In the second part, a facile and low-toxicity approach was proposed to synthesize a new magnetic adsorbent (Fe3O4@PDA@RGO) to remove the methylene blue (MB) in water samples. Dopamine can directly adhere to Fe3O4by one-step self-polymerization reaction, which serves as a reducing agent as well as a coupling agent for the assembly of reduced graphene oxide (RGO). The synthetic progress involves no additional chemicals and thermal treatments. Transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Raman spectroscopy are used to characterize the magnetic composite nanoparticles. The results demonstrate that Fe3O4@PDA@RGO has strong magnetism and exhibits high adsorption capacity to methylene blue. The adsorption behavior of MB on Fe3O4@PDA@RGO can be described by the pseudo-second-order kinetics model and Langmuir isotherm. Furthermore, the as-prepared adsorbent can be easily recovered and reused at least ten times due to the high magnetization and stability.In the third part, magnetic mesoporous (MMP) carbon has been successfully synthesized by using Fe3O4NPs, CaCO3and dopamine as cores, template, and carbon precursor, respectively. The synthetic procedure of MMP carbon is simple, low-cost and involves no organic solvents. The generated MMP carbon has a large surface area and strong magnetism. MMP carbon is used to remove2,4,6-trichlorophenol (TCP) from water samples. The results show that adsorption equilibrium is observed within10h, and the kinetics can be described by pseudo-second-order kinetic model. TCP adsorption is not affected by ionic strength and increases with temperature and initial concentration. When the TCP initial concentrations are10and100mg L’1, the adsorption capacity are117and610mg g-1, respectively, which are much higher than those achieved from other adsorbents. The results indicate that most of the adsorption sites on the MMP carbon are available for TCP due to the relatively large pore size.In the fourth part, we present a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) method for analysis of small molecule pollutants with metal-organic framework (MOFs:MOF-5, MOF-235, Cu-btc MOFs and Uio-66(Zr)-2OH) as matrix. The MOFs is easy to obtain and has large surface area and pore size. Benzo(a)pyrene (BaP) is chosen to investigate the matrix function of MOFs with MALDI measurement in positive reflection mode. Perfluorinated compounds PFOS is selected to investigate the performance of MOFs as MALDI matrix in negative reflection mode. Compared to traditional matrix, small molecule pollutants could even be successfully detected at5pg and no apparent background noise exist in the mass spectrum with MOFs as matrix of MALDI-TOF-MS. Therefore, MOFs is highly recommended as a potential matrix for further MALDI-TOF-MS studies on small molecule pollutes analysis.