Synthesis Of Carbon Quantum Dots And Their Photocatalytic Deg Radation Activity Of Organic Dye

As a new star of carbon nanomaterials,carbon quantum dots ar~e spherical carbon particles with a size below 10 nm.Carbon quantum dots are widely used in biomarkers,nanosensors,immunoassays,ion detection,photocatalysis,etc.due to their non-toxicity,high chemical stability,good biocompatibility and photoluminescence properties.Therefore,it has received extensive attention from scholars at home and abroad.A simple hydrothermal approach is used to prepare watersoluble carbon quantum dots(W-CQDs)by using glucose as the precursor and PE0106PP070PE0106(F127)as the controlling agent.The homogeneous W-C.QDs have an average size of 2.6nm and show well dispersibility.W-CQDs/mesoporous SiO2 composites are synthesized by using mesoporous SiO2 as the carrier.The fluorescenceintensity and quantum yield of the composite are higherthan those of W-CQDs.A synthesis stirategy of fluorescent carbon quantum dots(CQDs)with high quantum yield(QY)using aqua mesophase pitch(AMP)as the carbon source has been developed via the hydrothermal method in this study.The hydirothermial temperature and soaking time have important effects on the morphology and QY of CQDs.As-prepared CQDs at 120 ? holding for 24 h(CQDs-120-24)have the uniform size of about 2.8 nm5 and the QY can reach 27.6%.The obtained CQDs are successfully modified with ammonia and thionyl chloride respectively,and they exhibit an excellent photocatalytic performance on degrading rhodamine B(Rh B),methyl blue(MB)and indigo carmine(IC).Importantly,the degradation percentage of N-CQDs on Rh B under natural light for 4 h reaches 97%with the degradation rate constant of 0.02463 min-1 and it can maintain 93%after repetitively used 5 times.The results indicate that these as-prepared CQDs have the potential application in degrading organic dyes.