Carbon dots(CDs), as a new member of carbon nanomaterial family, have aroused great interest since their discovery in 2004. Because of their outstanding water solubility, high sensitivity and selectivity to target ana...Carbon dots(CDs), as a new member of carbon nanomaterial family, have aroused great interest since their discovery in 2004. Because of their outstanding water solubility, high sensitivity and selectivity to target analytes, low toxicity, favorable biocompatibility, and excellent photostability, researchers from diverse disciplines have come together to further develop the fundamental properties of CDs. Many methods for the production of CDs have been reported, therein, hydrothermal and solvothermal technology needs simple equipments, and microwave synthesis needs less reaction time, hence these methods become current common synthesis methods, in which many precursors have been applied to produce CDs. Due to their excellent fluorescence, CDs have made impressive strides in sensitivity and selectivity to a diverse array of salt ions,organic/biological molecules and target gases. The development of CDs as nanoprobes is still in its infancy, but continued progress may lead to their integration into environmental and biological applications. Hydrothermal,solvothermal, and microwave synthesis of fluorescent carbon dots and their detection applications as nanoprobes in salt ions, organic/biological molecules, and target gases will be reviewed.展开更多
Lithium iron phosphate （LiFePO4） doped with magnesium was hydrothermally synthesized from commercial LiOH, FeSO4, H3PO4 and MgSO4 with glucose as carbon precursor in aqueous solution. The samples were characterized ...Lithium iron phosphate （LiFePO4） doped with magnesium was hydrothermally synthesized from commercial LiOH, FeSO4, H3PO4 and MgSO4 with glucose as carbon precursor in aqueous solution. The samples were characterized by X-ray powder diffraction, scanning electron microscopy and constant charge-discharge cycling. The results show that the synthesized powders have been in situ coated with carbon precursor produced from caramel reaction of glucose. At ambient temperature （28±2℃）, the electrochemical performances of LiFePO4 prepared exhibit the high discharge capacity of 135 mAh g^-1 at 5C and good capacity retention of 98% over 90 cycles. The excellent electrochemical performances should be correlated with the intimate contact between carbon and LiFePO4 primary and secondary particles, resulting from the in situ formation of carbon precursor/carbon, leading to the increase in conductivity of LiFePO4.展开更多
To solve the problem of high temperature or long reaction time in hydrothermal synthesis of carbon dots （CDs）, a novel method based on the promoting carbonization by hydrochloric acid as catalysis was developed in p...To solve the problem of high temperature or long reaction time in hydrothermal synthesis of carbon dots （CDs）, a novel method based on the promoting carbonization by hydrochloric acid as catalysis was developed in present work. The acid catalyzed carbon dots （ACDs） were prepared facilely from tryptophan and phenylalanine at 200 ~C for 2 h. In our findings, the acids could promote significantly the formation of the ACDs＂ carbon core, as a result of the accelerating of the carbonization due to the easy deoxidation. The ACDs showed an average size of 4.8 nm, and consisted of high carbon crystalline core and various surface groups. The ACDs exhibited good optical properties and pH-dependent photoluminescence （PL） intensities. Furthermore, the ACDs were safe and biocompatible. The experimental results demonstrated that such new ACDs were connected with DNA-aptamer by EDC/NHS reaction maintaining both the bright fluorescence and recognizing ability on the cancer cells, which so could be served as an effective PL sensing platform. The resultant DNA-aptamer with ACDs （DNA-ACDs） could stick to human breast cancer cells （MCF-7） specifically, and exhibited high sensitivity and selectivity, indicating the potential applications in the cancer cells targeted imaging fields.展开更多
Porous carbon materials were prepared by hydrothermal carbonization(HTC) and KOH activation of camphor leaves and camellia leaves. The morphology, pore structure, chemical properties and CO2 capture ability of the por...Porous carbon materials were prepared by hydrothermal carbonization(HTC) and KOH activation of camphor leaves and camellia leaves. The morphology, pore structure, chemical properties and CO2 capture ability of the porous carbon prepared from the two leaves were compared. The effect of HTC temperature on the structure and CO2 adsorption properties was especially investigated. It was found that HTC temperature had a major effect on the structure of the product and the ability to capture CO2. The porous carbon materials prepared from camellia leaves at the HTC temperature of 240℃ had the highest proportion of microporous structure, the largest specific surface area(up to 1823.77m^2/g) and the maximum CO2 adsorption capacity of 8.30mmol/g at 25℃ under 0.4 MPa. For all prepared porous carbons, simulation results of isothermal adsorption model showed that Langmuir isotherm model described the adsorption equilibrium data better than Freundlich isotherm model. For porous carbons prepared from camphor leaves, pseudo-first order kinetic model was well fitted with the experimental data. However,for porous carbons prepared from camellia leaves, both pseudo-first and pseudo-second order kinetics model adsorption behaviors were present. The porous carbon materials prepared from tree leaves provided a feasible option for CO2 capture with low cost, environmental friendship and high capture capability.展开更多
A facile hydrothermal method was developed for the preparation of Fe_2O_3@C nanocomposites using FeCl_3·6H_2O as iron source and glucose as carbon source under alkaline condition. The morphology and structure of ...A facile hydrothermal method was developed for the preparation of Fe_2O_3@C nanocomposites using FeCl_3·6H_2O as iron source and glucose as carbon source under alkaline condition. The morphology and structure of the as-prepared product were identified by transmission electron microscopy(TEM), high resolution transmission electron microscopy(HRTEM), field-emission scanning electron microscopy(FESEM),X-ray diffraction(XRD), Raman spectroscopy, Fourier Transform infrared spectroscopy(FTIR), and thermogravimetric analysis(TGA). The as-prepare α-Fe_2O_3@C nanocomposites were employed for supercapacitor electrode material. The synergistic combination of carbon electrical double-layer capacitance and α-Fe_2O_3 pseudo-capacitance established such nanocomposites as versatile platform for high performance supercapacitors. The synthesis method developed here is expected to obtain other metal oxide/carbon composite.展开更多
基金supported by the National HighTech R&D Program of China (863 program, 2011AA050504)National Natural Science Foundation of China (21171117 and 61376003)+4 种基金Program for New Century Excellent Talents in University (NCET-12-0356)Shanghai Natural Science Foundation (13ZR1456600)Shanghai Science and Technology Grant (12JC1405700)Shanghai Pujiang Program (11PJD011)the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, and Medical-Engineering Crossover Fund (YG2012MS40 and YG2012MS32) of Shanghai Jiao Tong University
文摘Carbon dots(CDs), as a new member of carbon nanomaterial family, have aroused great interest since their discovery in 2004. Because of their outstanding water solubility, high sensitivity and selectivity to target analytes, low toxicity, favorable biocompatibility, and excellent photostability, researchers from diverse disciplines have come together to further develop the fundamental properties of CDs. Many methods for the production of CDs have been reported, therein, hydrothermal and solvothermal technology needs simple equipments, and microwave synthesis needs less reaction time, hence these methods become current common synthesis methods, in which many precursors have been applied to produce CDs. Due to their excellent fluorescence, CDs have made impressive strides in sensitivity and selectivity to a diverse array of salt ions,organic/biological molecules and target gases. The development of CDs as nanoprobes is still in its infancy, but continued progress may lead to their integration into environmental and biological applications. Hydrothermal,solvothermal, and microwave synthesis of fluorescent carbon dots and their detection applications as nanoprobes in salt ions, organic/biological molecules, and target gases will be reviewed.
文摘Lithium iron phosphate （LiFePO4） doped with magnesium was hydrothermally synthesized from commercial LiOH, FeSO4, H3PO4 and MgSO4 with glucose as carbon precursor in aqueous solution. The samples were characterized by X-ray powder diffraction, scanning electron microscopy and constant charge-discharge cycling. The results show that the synthesized powders have been in situ coated with carbon precursor produced from caramel reaction of glucose. At ambient temperature （28±2℃）, the electrochemical performances of LiFePO4 prepared exhibit the high discharge capacity of 135 mAh g^-1 at 5C and good capacity retention of 98% over 90 cycles. The excellent electrochemical performances should be correlated with the intimate contact between carbon and LiFePO4 primary and secondary particles, resulting from the in situ formation of carbon precursor/carbon, leading to the increase in conductivity of LiFePO4.
基金This work was supported by the Major Program of National Natural Science Foundation of China （No. 21334005）, the National Natural Science Foundation of China （Nos. 21304021 and 21432008）, and the National Basic Research Program of China （Nos. 2010CB732203 and 2012CB720603）.
文摘To solve the problem of high temperature or long reaction time in hydrothermal synthesis of carbon dots （CDs）, a novel method based on the promoting carbonization by hydrochloric acid as catalysis was developed in present work. The acid catalyzed carbon dots （ACDs） were prepared facilely from tryptophan and phenylalanine at 200 ~C for 2 h. In our findings, the acids could promote significantly the formation of the ACDs＂ carbon core, as a result of the accelerating of the carbonization due to the easy deoxidation. The ACDs showed an average size of 4.8 nm, and consisted of high carbon crystalline core and various surface groups. The ACDs exhibited good optical properties and pH-dependent photoluminescence （PL） intensities. Furthermore, the ACDs were safe and biocompatible. The experimental results demonstrated that such new ACDs were connected with DNA-aptamer by EDC/NHS reaction maintaining both the bright fluorescence and recognizing ability on the cancer cells, which so could be served as an effective PL sensing platform. The resultant DNA-aptamer with ACDs （DNA-ACDs） could stick to human breast cancer cells （MCF-7） specifically, and exhibited high sensitivity and selectivity, indicating the potential applications in the cancer cells targeted imaging fields.
基金financially supported by the National Natural Science Foundation of China (Nos. U1760119, 51472160 and U1560108)the Shanghai Nature Science Foundation (No. 16ZR1423400)the Science and Technology Commission of Shanghai Municipality (Nos. 15JC1490700 and 16JC1402200)
文摘Porous carbon materials were prepared by hydrothermal carbonization(HTC) and KOH activation of camphor leaves and camellia leaves. The morphology, pore structure, chemical properties and CO2 capture ability of the porous carbon prepared from the two leaves were compared. The effect of HTC temperature on the structure and CO2 adsorption properties was especially investigated. It was found that HTC temperature had a major effect on the structure of the product and the ability to capture CO2. The porous carbon materials prepared from camellia leaves at the HTC temperature of 240℃ had the highest proportion of microporous structure, the largest specific surface area(up to 1823.77m^2/g) and the maximum CO2 adsorption capacity of 8.30mmol/g at 25℃ under 0.4 MPa. For all prepared porous carbons, simulation results of isothermal adsorption model showed that Langmuir isotherm model described the adsorption equilibrium data better than Freundlich isotherm model. For porous carbons prepared from camphor leaves, pseudo-first order kinetic model was well fitted with the experimental data. However,for porous carbons prepared from camellia leaves, both pseudo-first and pseudo-second order kinetics model adsorption behaviors were present. The porous carbon materials prepared from tree leaves provided a feasible option for CO2 capture with low cost, environmental friendship and high capture capability.
基金the National Natural Science Foundation of China (nos. 21403091 and 51473070)the Natural Science Foundation of Jiangsu Province (no. BK20140557)+1 种基金a project funded by Jiangsu University for Senior Intellectuals (grant no. 12JDG093)the Jiangsu Province for support under the innovation/entrepreneurship program (Suzutong [2012]19)
文摘A facile hydrothermal method was developed for the preparation of Fe_2O_3@C nanocomposites using FeCl_3·6H_2O as iron source and glucose as carbon source under alkaline condition. The morphology and structure of the as-prepared product were identified by transmission electron microscopy(TEM), high resolution transmission electron microscopy(HRTEM), field-emission scanning electron microscopy(FESEM),X-ray diffraction(XRD), Raman spectroscopy, Fourier Transform infrared spectroscopy(FTIR), and thermogravimetric analysis(TGA). The as-prepare α-Fe_2O_3@C nanocomposites were employed for supercapacitor electrode material. The synergistic combination of carbon electrical double-layer capacitance and α-Fe_2O_3 pseudo-capacitance established such nanocomposites as versatile platform for high performance supercapacitors. The synthesis method developed here is expected to obtain other metal oxide/carbon composite.
