Preparation,Properties And Application Of Perovskite Quantum Dots And Metal-Organic Framework Composites

Lead-halide perovskite quantum dots represented by MPbX3(M =CH3NH3,Cs;X=Cl,Br,I)have shown great application prospects in the fields of lighting,display,photoelectric detection and photovoltaics,and how to coordinate or improve performance and enhance stability are the main problems in the application of such materials.Metal-organic frameworks(MOFs),as a porous crystalline materia]with various functional properties,can be used as a host to provide an ideal carrier for guest molecules and realize functional recombination.Therefore,this paper synergistically regulates the luminescent properties and stability of lead-halide perovskite quantum dots by choosing different metal-organic framework materials,and explores the applications of perovskite quantum dots and metal-organic framework composites in the fields of fluorescence sensing,optical anti-counterfeiting and backlight light emitting diodes(LED).The main research results of this paper are as follows:(1)CH3NH3PbBr3@MOF-5 composites were fabricated by two-step method.The effects of water and temperature on the luminescent properties of the composites were investigated.It was found that CH3NH3PbBr3@MOF-5 composites had good water resistance and stuctural stability.The potential applications of materials in the field of temperature sensing have been studied.It is further applied to the detection of common heavy metal ions in aqueous solution,and the sensitive and rapid detection of different metal ions by this kind of composite materials is realized.(2)CH3NH3PbBr3@EuBTC composites with multi-fluorescence emission centers were designed.The discoloration properties and spectral regulation mechanism of CH3NH3PbBr3@EuBTC composites under different excitation wavelength,temperature and polar solvent conditions were studied.The discoloration films could be further prepared by the combination of CH3NH3PbBr3C@EuBTC composites and PDMS,CH3NH3PbBr3@EuBTC"anti-counterfeiting ink" can also be obtained,and its application in the field of optical anti-counterfeiting is explored.(3)The in-situ preparation of all-inorganic perovskite quantum dot CsPbX3(X = Br,Br1.2/I1.8)@Uio-67 composites was carried out by an improved hot-injection method.The composite mechanism of green and red emitting CsPbX3(X = Br,Br1.2/I1.8)@UiO-67 composites and the light stability in air environment were studied.The white LED constructed by CsPbX3(X = Br,Br1.2/I1.8)@Uio-67 composite material can reach 138%NTSC,which indicates the application prospect of its backlight LED display fields.