Titania-based composite catalysts were prepared through a sol-gel route employing multi-walled carbon nanotubes with different diameters. The materials were characterized using thermogravimetric analysis, nitrogen ads...Titania-based composite catalysts were prepared through a sol-gel route employing multi-walled carbon nanotubes with different diameters. The materials were characterized using thermogravimetric analysis, nitrogen adsorption-desorption isotherm, powder X-ray diffraction, scanning electron microscopy, and diffuse reflectance UV-Vis absorption spectra. The application of the catalysts to photocatalytic degradation of phenol was tested under UV-Vis irradiation. A synergetic effect on phenol removal was observed in case of composite catalysts, which was evaluated in terms of apparent rate constant, total organic carbon removal and photonic efficiency.展开更多
Recently,MnO2 has gained attention as an electrode material because of its very high theoretical capacity and abundant availability.However,the very high volumetric change caused by its conversion-type reaction result...Recently,MnO2 has gained attention as an electrode material because of its very high theoretical capacity and abundant availability.However,the very high volumetric change caused by its conversion-type reaction results in bad reversibility of charge-discharge.In this study,δ-MnO2 of thickness 8 nm anchored on the surface of carbon nanotubes(CNT)by Mn-O-C chemical bonding is synthesized via a facile hydrothermal method.Numerous ex-situ characterizations of the lithium storage process were performed.Furthermore,density functional theory(DFT)calculations indicated thatδ-MnO2(012)thermodynamically prefers bonding with CNTs.Moreover,the interfacial interaction reinforces the connection of Mn-O and reduces the bond strength of Li-O in lithiated MnO2,which could facilitate an intercalation-type lithium storage reaction.Consequently,the as-synthesizedδ-MnO2 retains an excellent reversible capacity of 577.5 mAh g-1 in 1000 cycles at a high rate of 2 A g-1 between 0.1 V and 3.0 V.The results of this study demonstrate the possibility of employing the cost-effective transition metal oxides as intercalation lithium storage dominant electrodes for advanced rechargeable batteries.展开更多
Single-walled carbon nanotubes （SWNTs） possess high conductivity, mechanical strength, transparency, and flexibility, and are thus suitable for use in flexible electronics, transparent electrodes, and energy-storage...Single-walled carbon nanotubes （SWNTs） possess high conductivity, mechanical strength, transparency, and flexibility, and are thus suitable for use in flexible electronics, transparent electrodes, and energy-storage and energy-harvesting applications. However, to exploit these properties, SWNTs must be de-bundled in a surfactant solution to permit processing and use. We report a new method to prepare a SWNT-based transparent conducting film （TCF） using the diazo dye 3,3＇-（[1,1＇-biphenyl]-4,4＇-diyl）bis（4-amino naphthalene-1-sulfonic acid）, commonly known as Congo red （CR）, as a dispersant. Uniform 20-nm-thick TCFs were prepared on rigid glass and flexible polyethylene terephthalate （PET） substrates. The CR-SWNT dispersion and the CR-SWNT TCFs were characterized via UV-Vis-NIR, Raman spectroscopy, FT-IR spectroscopy, transmission electron microscopy （TEM）, field-emission scanning electron microscopy （FE-SEM） and dynamic light scattering （DLS） measurements. The sheet resistivity of the CRSWNT TCF was -34 ±6.6 Ω/□ with a transmittance of 81% at 550 nm, comparable to that of indium tin oxide-based films. Unlike SWNT dispersions prepared in common surfactants, such as sodium dodecyl sulfate （SDS）, sodium cholate （SC）, and Triton X-100, the CR-SWNT dispersion was amenable to forming TCF by drop coating. The CR-SWNT TCF was also very stable, maintaining a very low sheet resistivity even after 1,000 consecutive bending cycles of 8 mm bending radius. Further, manganese dioxide （MnO2） was electrochemically deposited on the CR-SWNT-PET film （MnO2-CR-SWNT-PET）. The as-prepared MnO2- CR-SWNT-PET electrode exhibited high specific capacitance and bendability, demonstrating promise as a candidate electrode material for flexible supercapacitors.展开更多
Multi-walled carbon nanotubes （MWNTs） were covalently and non-covalently functionalized with tetra- （4-hydroxylphenyl） porphyrin （THPPH2） and its complexes （ZnTHPP） forming dispersible nanohybrids in organic s...Multi-walled carbon nanotubes （MWNTs） were covalently and non-covalently functionalized with tetra- （4-hydroxylphenyl） porphyrin （THPPH2） and its complexes （ZnTHPP） forming dispersible nanohybrids in organic solution. The morphology of the nanohybrids was observed with transmission electron microscopy. The structure of the product was characterized by FT-IR, UV-Vis spectrophotometer, fluorescence spectroscopy and thermogravim- etric analysis. The photo-induced electron-transfer process of the nanohybrids in organic solution was also revealed.展开更多
基金ACKNOWLEDGMENT This work was supported Science Foundation of China by the National Natural （No.20703042）.
文摘Titania-based composite catalysts were prepared through a sol-gel route employing multi-walled carbon nanotubes with different diameters. The materials were characterized using thermogravimetric analysis, nitrogen adsorption-desorption isotherm, powder X-ray diffraction, scanning electron microscopy, and diffuse reflectance UV-Vis absorption spectra. The application of the catalysts to photocatalytic degradation of phenol was tested under UV-Vis irradiation. A synergetic effect on phenol removal was observed in case of composite catalysts, which was evaluated in terms of apparent rate constant, total organic carbon removal and photonic efficiency.
基金financially supported by the National Key Research and Development Program of China(Grant No.2018YFB0104302)the National Natural Science Foundation of China(Grant No.51872026)。
文摘Recently,MnO2 has gained attention as an electrode material because of its very high theoretical capacity and abundant availability.However,the very high volumetric change caused by its conversion-type reaction results in bad reversibility of charge-discharge.In this study,δ-MnO2 of thickness 8 nm anchored on the surface of carbon nanotubes(CNT)by Mn-O-C chemical bonding is synthesized via a facile hydrothermal method.Numerous ex-situ characterizations of the lithium storage process were performed.Furthermore,density functional theory(DFT)calculations indicated thatδ-MnO2(012)thermodynamically prefers bonding with CNTs.Moreover,the interfacial interaction reinforces the connection of Mn-O and reduces the bond strength of Li-O in lithiated MnO2,which could facilitate an intercalation-type lithium storage reaction.Consequently,the as-synthesizedδ-MnO2 retains an excellent reversible capacity of 577.5 mAh g-1 in 1000 cycles at a high rate of 2 A g-1 between 0.1 V and 3.0 V.The results of this study demonstrate the possibility of employing the cost-effective transition metal oxides as intercalation lithium storage dominant electrodes for advanced rechargeable batteries.
文摘Single-walled carbon nanotubes （SWNTs） possess high conductivity, mechanical strength, transparency, and flexibility, and are thus suitable for use in flexible electronics, transparent electrodes, and energy-storage and energy-harvesting applications. However, to exploit these properties, SWNTs must be de-bundled in a surfactant solution to permit processing and use. We report a new method to prepare a SWNT-based transparent conducting film （TCF） using the diazo dye 3,3＇-（[1,1＇-biphenyl]-4,4＇-diyl）bis（4-amino naphthalene-1-sulfonic acid）, commonly known as Congo red （CR）, as a dispersant. Uniform 20-nm-thick TCFs were prepared on rigid glass and flexible polyethylene terephthalate （PET） substrates. The CR-SWNT dispersion and the CR-SWNT TCFs were characterized via UV-Vis-NIR, Raman spectroscopy, FT-IR spectroscopy, transmission electron microscopy （TEM）, field-emission scanning electron microscopy （FE-SEM） and dynamic light scattering （DLS） measurements. The sheet resistivity of the CRSWNT TCF was -34 ±6.6 Ω/□ with a transmittance of 81% at 550 nm, comparable to that of indium tin oxide-based films. Unlike SWNT dispersions prepared in common surfactants, such as sodium dodecyl sulfate （SDS）, sodium cholate （SC）, and Triton X-100, the CR-SWNT dispersion was amenable to forming TCF by drop coating. The CR-SWNT TCF was also very stable, maintaining a very low sheet resistivity even after 1,000 consecutive bending cycles of 8 mm bending radius. Further, manganese dioxide （MnO2） was electrochemically deposited on the CR-SWNT-PET film （MnO2-CR-SWNT-PET）. The as-prepared MnO2- CR-SWNT-PET electrode exhibited high specific capacitance and bendability, demonstrating promise as a candidate electrode material for flexible supercapacitors.
基金Project supported by the Natural Science Foundation of Guangdong Province, China （Nos. 9151503102000006, 7007735）.
文摘Multi-walled carbon nanotubes （MWNTs） were covalently and non-covalently functionalized with tetra- （4-hydroxylphenyl） porphyrin （THPPH2） and its complexes （ZnTHPP） forming dispersible nanohybrids in organic solution. The morphology of the nanohybrids was observed with transmission electron microscopy. The structure of the product was characterized by FT-IR, UV-Vis spectrophotometer, fluorescence spectroscopy and thermogravim- etric analysis. The photo-induced electron-transfer process of the nanohybrids in organic solution was also revealed.
基金supported by the Important Directional Project of ' the Research and Exploration of Supercapacitor Storage System for Electric Vehicle' from Dalian Institute of Chemical Physics,Chinese Academy of Sciences,China~~
