Preparation Of Carbon Quantum Dots By Pyrolysis Of L-glutamic Acid And Their Fluorescence Properties

Carbon quantum dots(Carbon quantum dots,CQDs)due to the unique fluorescence characteristics might replace fluorescent semiconductor quantum dots as a new Carbon nano materials,it is soluble in water,no light flashing,non-toxic,and the advantages of resistance to photobleaching,which makes it photocatalytic electrochemical sensing cells in the biological sensing imaging and drug delivery application potential is tremendous,and thus received extensive attention of the scientific community and industry.As a result,it has received extensive attention from the scientific and industrial communities.In this paper,With sinistral L-glutamic acid as the carbon source,ammonia solution of baking soda solution soda solution and deionized water as modifier,the pyrolysis carbon composite fluorescence quantum dots by transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),ultraviolet-visible absorption spectrum(UV-Vis)to analytical means such as hair spectroscopy(PL)characterization of morphology and optical properties of carbon quantum dots,the different pH modifier modified carbon source and the quality of the structure of fluorescent carbon quantum dots with fluorescence properties and the effect of study.Researches show that:1.Left glutamic acid as the carbon source,pH=7 hartshorn as modification agent,thermal decomposition method is used to synthesize carbon quantum dots,when L-glutamic acid as modifier ammonia than are known,the quality of the 3:50p.m,synthesis of carbon quantum dot size uniform distribution,the average particle size in 2.5 ~ 5.5 nm and 3.3 ~ 5.7 nm range,and the surface-C=O,-O-C=O,-OH,-COOH groups,including-OH,-COOH and the existence of two kinds of hydrophilic group,enhancing the water soluble carbon quantum dots.2.With the ammonia water solution pH=7 Soda solution,Baking soda solution and deionized water as modifier,and take a left-handed glutamate acid than with the quality of the modifier for known synthetic carbon quantum dots,compare different modifier on absorption and luminescence properties of carbon quantum dots,findthem under the single wavelength ultraviolet irradiation,launch blue fluorescence,the fluorescence emission wavelength were similar,the strongest between 414~418 nm.3.As modifier quality than left-handed glutamic acid and ammonia are respectively known 3:50,4:50,5:50 right,modifier of synthetic carbon quantum dots XPS analysis,the results showed that carbon quantum dots has a great influence by modifying agent,preparation of carbon quantum dots have been analyzed for nitrogen doped carbon quantum dots,mainly for the Pyrrolic N and Pyridinic N two kinds of forms of nitrogen doping.4.When glutamic acid and ammonia solution quality than for 3:50 p.m.,pyrolysis sinistral glutamic acid,change of the ammonia solution pH value,preparation of different carbon quantum dots,found the photoluminescence properties of carbon quantum dots is affected by pH modification agent,when the pH value of the ammonia solution by weak acid to weak alkaline,the strongest emission wavelength of CQDs followed changes.