Preparation Of Luminescent Mercapto Coordination Compounds And Their Application In Detection Of Metal Ions

Fluorescent materials have been concerned and researched by researchers own to their unique luminous properties.At the same time,fluorescent materials have been widely used in many fields,such as fluorescence molecular probes,bio-imaging,photoresponse,light-emitting diodes(LEDs)and solar cells.In this thesis,three groups of fluorescent materials were synthesized by combustion,solvothermal and agitation,respectively.Their properties and application were investigated too.The main contents are as follows:(1)Synthesis of carbon nanoparticles(Au-C NPs)with high fluorescence properties and their detection to Fe3+ and Hg2+Carbon nanoparticles(Au-C NPs)with fluorescent properties were prepared by direct combustion of a mixture of chloroauric acid(HAuCl4)and glutathione(GSH)without any solvent involved in the reaction.The carbon nanoparticles were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM),infrared spectroscopy(IR).The results show that Au is encapsulated in the carbon particles,and the surface of carbon nanoparticles is modified by a large number of organic groups.The selective response of the obtained Au-C NPs is explored for metal ions.There are thirteen kinds of metal ions to be detected.The results showed that Au-C NPs were able to recognize Fe3+and Hg2+ ions.There is a good linear correlation between fluorescence intensity of Au-C NPs and ions concentration when the concentration of Fe3+ at the range of 1.0*10-5 to 2.0*10-3 M and the concentration of Hg2+ at the range of 5.0*10-5 to 3.0*10-2 M,respectively.In addition,we also investigated the response of Au-C NPs to Fe3+ and Hg2+ in actual water samples.The results show that Au-C NPs can respond well to the two ions in real water samples,and not being affected by other ions and impurities from the actual water samples.(2)Synthesis of graphene quantum dots(GQDs)with high fluorescence properties and their detection to Fe3+Based on the previous studies,graphene quantum dots with fluorescence properties were prepared by solvothermal method using glutathione(GSH)as the carbon source and ethylene glycol as the solvent.The surface of graphene quantum dots(SN-GQDs)were modified by hydroxyl group(-OH),carboxyl group(-COOH),amino group(-NH2)and sulfhydryl group(-SH)in the absence of AgNO3.When AgNO3 were added to the reaction system,surface of the graphene quantum dots(N-GQDs)had no-SH because of formation of Ag2S.That is to say,-SH comes off from the surface of graphene quantum dots.The phase,morphology and element components of the GQDs were characterized by XRD,TEM,Atomic force microscope(AFM),XPS and IR.The detection of the two quantum dots to metal ions was explored.There are thirteen kinds of metal ions to be detected.It was found that SN-GQDs had a specific ion response to Hg2+.Unlike SN-GQDs,N-GQDs have response to Fe3+ and there are a good linear correlation between the concentration of Fe3+ and the relative fluorescence intensity at the range of 5.0*10-5 to 2.0*10-3 M.(3)Preparation of white light from trichromatic fluorescent materialThe two thiol complexs(2-mercaptobenzothiazole and 2-mercaptopyridine)are used to synthesize fluorescence materials.Two kinds of thiol-containing organic compounds,which were capable of emitting red fluorescence and yellow-green fluorescence due to aggregation-induced emission(AIE),were prepared.In combination with the previously synthesized blue fluorescent quantum dots,the proportion of the fluorescent materials in the three primary colors was adjusted to obtain a fluorescent material capable of emitting white light.