Controllable Fabrication Of Two-Dimensional Coordination Polymers Nanocrystals And Their Properties

Two-dimensional（2D）coordination Polymers（CPs）nanomaterials,have some advantages like other 2D materials,such as high specific surface area,easy to film,surface chemistry can be modified,etc.,which makes it be an intersection of attention for current chemical and material scientists.In this thesis,we prepared different kinds of monodisperse 2D CPs nanostructures based on porphyrin,C₂-symmetric and C₃-symmetric ligands through the anionic-surfactant-assisted self-assembly strategy which we proposed and study their properties.The main research work is as follows,1.With the anionic-surfactant-assisted self-assembly strategy,a series of 2D metallo-porphyrins（MPFs）nanosheets based on two organic ligands,namely tetra（4-pyridyl）porphyrin（TPyP）,tetrakis（4-carboxyphenyl）porphyrin（TCPP）,have been respectively synthesized and the effects of surfactant type,reaction time and temperature on the synthesis of nanosheets were systematically studied.The morphology,aggregation and properties of these nanosheets were characterized,the results show that the M-TPyP/TCPP nanosheets with good dispersibility,stability and uniformity.Through data analysis of the XRD,spectral and TG,we surmise that the anionic head groups SO₄^2-of SDS might bind with uncoordinated metal ions in the outer layer of crystal nucleus by the electrostatic interactions acts as a capping agent,in the liquid phase system,SDS will preferentially attach on the crystal facets with the highest metal ions percentage to restrict the growth rate of this crystal facets,inducing the anisotropic growth to restrict the growth of MPFs in one of three dimensions and then finally formation of ultrathin MPF nanosheets.2.The above-mentioned porphyrin systems were used as the research object,and the surfactants CTAB and PVP with different charge types were selected to replace SDS under the same experimental conditions.For CATB and PVP,SEM results show that MPFs nanocrystals are more likely to produce zero-dimensional,three-dimensional nanostructures such as Cu/Zn-TPyP nanopolyhedron,CuTCPP nanoclusters etc.,the XRD patterns show that the samples compared with the SDS system have different space groups and dominant crystal facets,the Soret band absorption peaks of Cu/ZnTPyP nanostructures in UV-Vis spectra have obvious blue shift and they show the Haggregation of TPyP molecular,while for the samples in SDS system with the red shift of absorption peak and J-aggregation.The abovementioned results showed that the metallo-porphyrin nanocrystals undergo a different growth process comparing with SDS,they mainly depend on the specific morphology of surfactant micelles,completing the self-assembly process to control the morphology and size of the metalloporphyrin nanocrystals.3.MOF-5 and HKUST-1 nanosheets were successfully prepared by using the ligands 1,4-benzenedicarboxylate（H₂BDC）and Trimesic acid（H₃BTC）respectively as the building unit and the effects of SDS,CTAB and PVP on the structures,size and morphology of coordination polymer nanostructures were also studied.