A synthesis strategy 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 hydrothe...A synthesis strategy 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 hydrothermal 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 nm, 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.展开更多
Long-range order crystalline thin films of organic semiconductors have attracted wide attention owing to their high charge carrier mobility.However,uncontrolled crystal nucleation and growth during the thin film dryin...Long-range order crystalline thin films of organic semiconductors have attracted wide attention owing to their high charge carrier mobility.However,uncontrolled crystal nucleation and growth during the thin film drying process cause the formation of grain boundaries,thereby limiting the long-range order.Herein,we achieved the oriented nucleation and growth of organic semiconductors by off-centre spin-coating at the temperature of the smectic E(SmE)liquid crystal mesophase,and then followed by Ostwald ripening during solvent vapour annealing.The thin film of 2-(5-heptylthiophen-2-yl)[1]benzothieno[3,2-b][1]benzothiophne(C7-T-BTBT)blended with 40%(mass fraction)poly(methyl methacrylate)(PMMA)was prepared by off-centrespin-coating at SmE mesophase(170°C),followed by solvent vapour annealing in chloroform for 24 h(chloroform is a good solvent for C7-T-BTBT and PMMA).The C7-T-BTBT molecules grew to rod-like crystals,which were mostly arranged parallel to each other.The crystal growth was perfect and resulted in a single crystal.The average length of the crystals was approximately 87µm.Moreover,the highest charge carrier mobility is 1.62 cm^(2)·V^(−1)·s^(−1) as against that of the film prepared at 25°C(0.06 cm^(2)·V^(−1)·s^(−1)).展开更多
A self-assembling bis-pyrene （BP） molecule with π-π interactions was designed and synthesized. In condensed state, the BP self-assembled into highly-ordered mesophase at room temperature, which was characterized b...A self-assembling bis-pyrene （BP） molecule with π-π interactions was designed and synthesized. In condensed state, the BP self-assembled into highly-ordered mesophase at room temperature, which was characterized by using differential scanning calorimetry （DSC）, polarized optical microscope （POM）, and 1 D wide angle X-ray diffraction （WAXD） techniques. In solution, the BP self-assembled into nanoflbers in the mixed dichloromethane and hexane （1：1 volume ratio） solvent. Interestingly, the BP was not fluorescent when dissolved in dichloromethane solution. However, the self-assembled nanostructures of BP in the mixed solvent showed high intensity of green fluorescence. The advantages of self-assembly and fluorescence feature exhibited that BP could be promising fluorescence nanoprobes or nanosensors for various applications.展开更多
基金supported by the fund of the Beijing Laboratory for Food Quality and Safety, Beijing Technology and Business University (Grant No. FQS-201709)China Postdoctoral Science Foundation Funded Project (Grant No. 2016M592824)+1 种基金the Science and Technology Plan of Yulin City (Grant No. 2016-16-7)the Science and Technology Plan of Beilin District (Grant No. GX1710)
文摘A synthesis strategy 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 hydrothermal 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 nm, 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.
基金supported by the National Natural Science Foundation of China(Nos.51933010,91833306,52003269)the Key Scientific and Technological Innovation Team Project of Shaanxi Province,China(No.2020TD-002).
文摘Long-range order crystalline thin films of organic semiconductors have attracted wide attention owing to their high charge carrier mobility.However,uncontrolled crystal nucleation and growth during the thin film drying process cause the formation of grain boundaries,thereby limiting the long-range order.Herein,we achieved the oriented nucleation and growth of organic semiconductors by off-centre spin-coating at the temperature of the smectic E(SmE)liquid crystal mesophase,and then followed by Ostwald ripening during solvent vapour annealing.The thin film of 2-(5-heptylthiophen-2-yl)[1]benzothieno[3,2-b][1]benzothiophne(C7-T-BTBT)blended with 40%(mass fraction)poly(methyl methacrylate)(PMMA)was prepared by off-centrespin-coating at SmE mesophase(170°C),followed by solvent vapour annealing in chloroform for 24 h(chloroform is a good solvent for C7-T-BTBT and PMMA).The C7-T-BTBT molecules grew to rod-like crystals,which were mostly arranged parallel to each other.The crystal growth was perfect and resulted in a single crystal.The average length of the crystals was approximately 87µm.Moreover,the highest charge carrier mobility is 1.62 cm^(2)·V^(−1)·s^(−1) as against that of the film prepared at 25°C(0.06 cm^(2)·V^(−1)·s^(−1)).
基金supported by the National Natural Science Foundation of China(Nos. 51573031 and 51473188)
文摘A self-assembling bis-pyrene （BP） molecule with π-π interactions was designed and synthesized. In condensed state, the BP self-assembled into highly-ordered mesophase at room temperature, which was characterized by using differential scanning calorimetry （DSC）, polarized optical microscope （POM）, and 1 D wide angle X-ray diffraction （WAXD） techniques. In solution, the BP self-assembled into nanoflbers in the mixed dichloromethane and hexane （1：1 volume ratio） solvent. Interestingly, the BP was not fluorescent when dissolved in dichloromethane solution. However, the self-assembled nanostructures of BP in the mixed solvent showed high intensity of green fluorescence. The advantages of self-assembly and fluorescence feature exhibited that BP could be promising fluorescence nanoprobes or nanosensors for various applications.
