Sub-100 nm hollow carbon nanospheres with thin shells are highly desirable anode materials for energy storage applications. However, their synthesis remains a great challenge with conventional strategies. In this work...Sub-100 nm hollow carbon nanospheres with thin shells are highly desirable anode materials for energy storage applications. However, their synthesis remains a great challenge with conventional strategies. In this work, we demonstrate that hollow carbon nanospheres of unprecedentedly small sizes （down to - 32.5 nm and with thickness of - 3.9 nm） can be produced on a large scale by a templating process in a unique reverse micelle system. Reverse micelles enable a spatially confined Stober process that produces uniform silica nanospheres with significantly reduced sizes compared with those from a conventional Stober process, and a subsequent well-controlled sol-gel coating process with a resorcinol-formaldehyde resin on these silica nanospheres as a precursor of the hollow carbon nanospheres. Owing to the short diffusion length resulting from their hollow structure, as well as their small size and microporosity, these hollow carbon nanospheres show excellent capacity and cycling stability when used as anode materials for lithium/sodium-ion batteries.展开更多
Long-lasting SrAl2O4∶Eu, Dy phosphor was successfully prepared from a mesoporous precursor. The precursor was synthesized by templating method using nonionic Polyethylene Oxide (PEO) as surfactants, which was proved ...Long-lasting SrAl2O4∶Eu, Dy phosphor was successfully prepared from a mesoporous precursor. The precursor was synthesized by templating method using nonionic Polyethylene Oxide (PEO) as surfactants, which was proved by TG-DTG, X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) analysis. The analysis results indicated that regular cylindrical-to-hexagonal shaped pores with several nanometers were obtained. The structure and morphology of the SrAl2O4∶Eu, Dy phosphor by templating method was characterized by XRD and Scanning Electron Microscopy (SEM). The XRD results showed that a pure SrAl2O4 phase formed at 900 ℃ by templating method. The SEM morphologies of the obtained phosphors prepared by templating synthesis were uniform and porous multicrystalline with average diameter size of 5 μm. The broad-band UV-excited SrAl2O4∶Eu, Dy phosphor derived from a mosoporous precursor was observed at λmax=515 nm due to the transitions from the 4f65d1 to the 4f7 configurations of Eu2+ ion. The main excitation and emission intensity of the phosphor with this method were stronger than that obtained by solid state reaction method. And the obtained long-lasting phosphor with this method revealed a better afterglow compared to the phosphor prepared through solid state reaction method.展开更多
The shape-controlled silver nanostructures have been widely used for template synthesis of metal nanostructures with desired morphologies and compositions for specific applications by galvanic replacement reaction,whi...The shape-controlled silver nanostructures have been widely used for template synthesis of metal nanostructures with desired morphologies and compositions for specific applications by galvanic replacement reaction,while the silver is sacrificed as oxidized to silver ion and abandoned as by-products.In view of the broad application prospect of the obtained metal nanostructures,the cost and environment problems after the template reactions should be taken into account for the large scale production in the future.To solve this problem,we conceptually demonstrate that the wasted AgCl generated from the template reactions can be easily recycled for the synthesis of valuable Ag nanowires.As representative examples,the average recovery of silver can be about 69.8%-84.6% after the template synthesis of Au/Pt nanostructures.The resynthesized Ag nanowires show uniform size distribution and excellent physical and chemical properties for the fabrication of transparent electrode and template synthesis.展开更多
Nanoparticles of Ce0.6Zr0.35Y0.05O2 (CZY) solid solution have been prepared by the CTAB (hexadecyl-trimethyl ammonium bromide), CTAB-EG (ethylene glycol) templating, and CTAB-EG-NaCl (in which the pores of the precurs...Nanoparticles of Ce0.6Zr0.35Y0.05O2 (CZY) solid solution have been prepared by the CTAB (hexadecyl-trimethyl ammonium bromide), CTAB-EG (ethylene glycol) templating, and CTAB-EG-NaCl (in which the pores of the precursor synthesized by the CTAB-EG method is filled by a certain amount of NaCl) method, respectively. The physical properties of these materials were characterized by means of tech-niques such as X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and N2 adsorp-tion-desorption measurements. The CZY samples synthesized by the above three methods display wormhole-like mesoporous morphology and cubic crystal structures. The materials are narrow in pore size distribution (averaged pore diameter = 5.3―7.1 nm), high in surface areas (95―119 m2/g), and large in pore volumes (0.16―0.18 cm3/g). It has been demonstrated that the introduction of NaCl is capable of retaining the pore structures of solid nanomaterials at high-temperature calcination.展开更多
Highly ordered mesoporous silica HOM-5(cubic,Ia3d)with three-dimensional(3D)bicontinuous channels was fabricated under acidic condition via a direct-templating synthesis.Primary lyotropic liquid crystal mesophase of P...Highly ordered mesoporous silica HOM-5(cubic,Ia3d)with three-dimensional(3D)bicontinuous channels was fabricated under acidic condition via a direct-templating synthesis.Primary lyotropic liquid crystal mesophase of P123 was used as the template.The as-synthesized HOM-5 had thick walls of 15.0 nm.The mean pore diameter and specific surface area of the material were 5.7 nm and 500 m2·g-1,respectively.Results show that materials obtained from this simple synthesis are highly ordered with perfect meso-structures.The results of hydrothermal testing show that the as-synthesized silica retains Ia3d space group after refluxing in boiling water for 6 hours.展开更多
基金C. B. G. acknowledges the support from the National Natural Science Foundation of China （Nos. 21671156 and 21301138）, the Tang Scholar Program from the Cyrus Tang Foundation, and the start-up fund from Xi＇an Jiaotong University. X. G. H acknowledges the programs supported by State Key Laboratory of Electrical Insulation and Power Equipment （No. EIPE17306） and Young Talent Support Plan of Xi＇an Jiaotong University. Y. D. Y. acknowledges the support from U.S. Department of Energy （No. DE-SC0002247）.
文摘Sub-100 nm hollow carbon nanospheres with thin shells are highly desirable anode materials for energy storage applications. However, their synthesis remains a great challenge with conventional strategies. In this work, we demonstrate that hollow carbon nanospheres of unprecedentedly small sizes （down to - 32.5 nm and with thickness of - 3.9 nm） can be produced on a large scale by a templating process in a unique reverse micelle system. Reverse micelles enable a spatially confined Stober process that produces uniform silica nanospheres with significantly reduced sizes compared with those from a conventional Stober process, and a subsequent well-controlled sol-gel coating process with a resorcinol-formaldehyde resin on these silica nanospheres as a precursor of the hollow carbon nanospheres. Owing to the short diffusion length resulting from their hollow structure, as well as their small size and microporosity, these hollow carbon nanospheres show excellent capacity and cycling stability when used as anode materials for lithium/sodium-ion batteries.
基金the National Natural Science Foundation of China (20376009)
文摘Long-lasting SrAl2O4∶Eu, Dy phosphor was successfully prepared from a mesoporous precursor. The precursor was synthesized by templating method using nonionic Polyethylene Oxide (PEO) as surfactants, which was proved by TG-DTG, X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) analysis. The analysis results indicated that regular cylindrical-to-hexagonal shaped pores with several nanometers were obtained. The structure and morphology of the SrAl2O4∶Eu, Dy phosphor by templating method was characterized by XRD and Scanning Electron Microscopy (SEM). The XRD results showed that a pure SrAl2O4 phase formed at 900 ℃ by templating method. The SEM morphologies of the obtained phosphors prepared by templating synthesis were uniform and porous multicrystalline with average diameter size of 5 μm. The broad-band UV-excited SrAl2O4∶Eu, Dy phosphor derived from a mosoporous precursor was observed at λmax=515 nm due to the transitions from the 4f65d1 to the 4f7 configurations of Eu2+ ion. The main excitation and emission intensity of the phosphor with this method were stronger than that obtained by solid state reaction method. And the obtained long-lasting phosphor with this method revealed a better afterglow compared to the phosphor prepared through solid state reaction method.
基金supported by the National Natural Science Foundation of China(21431006)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(21521001)+2 种基金the National Basic Research Program of China(2014CB931800 and 2013CB931800)the Users with Excellence and Scientific Research Grant of Hefei Science Center of Chinese Academy of Sciences(CAS)(2015HSC-UE007 and 2015SRG-HSC038)the CAS(KJZD-EW-M01-1)
文摘The shape-controlled silver nanostructures have been widely used for template synthesis of metal nanostructures with desired morphologies and compositions for specific applications by galvanic replacement reaction,while the silver is sacrificed as oxidized to silver ion and abandoned as by-products.In view of the broad application prospect of the obtained metal nanostructures,the cost and environment problems after the template reactions should be taken into account for the large scale production in the future.To solve this problem,we conceptually demonstrate that the wasted AgCl generated from the template reactions can be easily recycled for the synthesis of valuable Ag nanowires.As representative examples,the average recovery of silver can be about 69.8%-84.6% after the template synthesis of Au/Pt nanostructures.The resynthesized Ag nanowires show uniform size distribution and excellent physical and chemical properties for the fabrication of transparent electrode and template synthesis.
基金the National Natural Science Foundation of China (Grant No. 20473006) and PHR (IHLB)
文摘Nanoparticles of Ce0.6Zr0.35Y0.05O2 (CZY) solid solution have been prepared by the CTAB (hexadecyl-trimethyl ammonium bromide), CTAB-EG (ethylene glycol) templating, and CTAB-EG-NaCl (in which the pores of the precursor synthesized by the CTAB-EG method is filled by a certain amount of NaCl) method, respectively. The physical properties of these materials were characterized by means of tech-niques such as X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and N2 adsorp-tion-desorption measurements. The CZY samples synthesized by the above three methods display wormhole-like mesoporous morphology and cubic crystal structures. The materials are narrow in pore size distribution (averaged pore diameter = 5.3―7.1 nm), high in surface areas (95―119 m2/g), and large in pore volumes (0.16―0.18 cm3/g). It has been demonstrated that the introduction of NaCl is capable of retaining the pore structures of solid nanomaterials at high-temperature calcination.
文摘Highly ordered mesoporous silica HOM-5(cubic,Ia3d)with three-dimensional(3D)bicontinuous channels was fabricated under acidic condition via a direct-templating synthesis.Primary lyotropic liquid crystal mesophase of P123 was used as the template.The as-synthesized HOM-5 had thick walls of 15.0 nm.The mean pore diameter and specific surface area of the material were 5.7 nm and 500 m2·g-1,respectively.Results show that materials obtained from this simple synthesis are highly ordered with perfect meso-structures.The results of hydrothermal testing show that the as-synthesized silica retains Ia3d space group after refluxing in boiling water for 6 hours.
