In this work,a novel vacuum-assisted strategy is proposed to homogenously form Metal-organic frameworks within hollow mesoporous carbon nanospheres(HMCSs)via a solid-state reaction.The method is applied to synthesize ...In this work,a novel vacuum-assisted strategy is proposed to homogenously form Metal-organic frameworks within hollow mesoporous carbon nanospheres(HMCSs)via a solid-state reaction.The method is applied to synthesize an ultrafine CoSe2 nanocrystal@N-doped carbon matrix confined within HMCSs(denoted as CoSe2@NC/HMCS)for use as advanced anodes in highperformance potassium-ion batteries(KIBs).The approach involves a solvent-free thermal treatment to form a Co-based zeolitic imidazolate framework(ZIF-67)within the HMCS templates under vacuum conditions and the subsequent selenization.Thermal treatment under vacuum facilitates the infiltration of the cobalt precursor and organic linker into the HMCS and simultaneously transforms them into stable ZIF-67 particles without any solvents.During the subsequent selenization process,the“dual confinement system”,composed of both the N-doped carbon matrix derived from the organic linker and the small-sized pores of HMCS,can effectively suppress the overgrowth of CoSe2 nanocrystals.Thus,the resulting uniquely structured composite exhibits a stable cycling performance(442 mAh g^−1 at 0.1 A g^−1 after 120 cycles)and excellent rate capability(263 mAh g^−1 at 2.0 A g^−1)as the anode material for KIBs.展开更多
Micron-sized hollow silica spheres whose shells are made up of mesocellular silica foams （MCFs） have been synthesized by one-pot sol-gel method in benzene/water/P123 emulsion. The material is characterized with SEM,...Micron-sized hollow silica spheres whose shells are made up of mesocellular silica foams （MCFs） have been synthesized by one-pot sol-gel method in benzene/water/P123 emulsion. The material is characterized with SEM, TEM, BET and ^29Si MAS NMR. The results show that the MCFs of the unique shell of hollow silica spheres were connected by large windows with a narrow distribution of - 10 nm in diameter, the inner space of the hollow sphere is accessible. And the formation mechanism of the hollow silica spheres is proposed. C 2009 Xin Wen Guo. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
The selective hydrogenolysis of glycerol exhibits great prospects,while the catalysts with high selectivity and activity are still missing and need to be created urgently.Herein,we report the synthesis of hollow mesop...The selective hydrogenolysis of glycerol exhibits great prospects,while the catalysts with high selectivity and activity are still missing and need to be created urgently.Herein,we report the synthesis of hollow mesoporous Pt/WO_(x)/SiO_(2)-TiO_(2)nanosphere catalysts with bi-functional interfaces synergistically for high efficiency conversion of glycerol to 1,3-propanediol.The hollow mesoporous Pt/WO_(x)/SiO_(2)-TiO_(2)catalysts show a typical brick-concrete liked framework with a high surface area(179.3 m^(2)·g^(-1)),large mesopore size(10.6 nm),uniform particle size(~400 nm),and ultrathin shell thickness(~75 nm).The brick anatase nanocrystals and concrete amorphous SiO_(2)networks can selectively rivet Pt nanoparticles and WO_(x)nanocluster species,respectively,thus constructing two interfaces for effective adsorption,rapidly catalytic dehydration and hydrogenation processes.The hollow mesoporous Pt/WO_(x)/SiO_(2)-TiO_(2)catalysts deliver a high selectivity of 53.8%for 1,3-propanediol(1,3-PDO)at a very high glycerol conversion of 85.0%.As a result,a favorable 1,3-PDO yield of 45.7%can be obtained with excellent stability,which is among the best performances of previously reported catalysts.This work paves a new way to synthesize catalysts with high selectivity,high activity and high stability.展开更多
Nowadays,multi-shelled mesoporous hollow metal oxide nanospheres have drawn a lot of attention due to their large internal space,nanometer scaled shell thickness,high specific surface area and well-defined mesopores,o...Nowadays,multi-shelled mesoporous hollow metal oxide nanospheres have drawn a lot of attention due to their large internal space,nanometer scaled shell thickness,high specific surface area and well-defined mesopores,of which unique nanostructure endows metallic oxides with enhanced properties.In this thesis,we have studied and proposed a versatile ligand-assisted cooperative template method to synthesize multi-shelled mesoporous hollow metal hydroxides and oxides nanospheres,in which silica nanospheres act as sacrificial templates and the coordination interaction between metal ions and surfactant can be cooperatively amplified by using chelating ligand(ascorbic acid)as a co-template.The synthesized metal hydroxides and oxides nanospheres possess stable hollow structure,uniform spherical morphology and tunable diameter from 270 to 690 nm.All the multi-shelled mesoporous hollow metal hydroxide and metal oxide nanospheres exhibit high surface areas(up to 640 m^(2)/g).The obtained Au nanoparticles loaded composited nanospheres exhibit excellent reactivity for solvent-free aerobic oxidation of ethylbenzene with high activity(28.2%)and selectivity(87%).展开更多
Hollow mesoporous metals have unique potential for catalysis,but their precise synthesis and further elaboration of their structure–performance relationships are still huge challenges.Herein,wereport a new synthetic ...Hollow mesoporous metals have unique potential for catalysis,but their precise synthesis and further elaboration of their structure–performance relationships are still huge challenges.Herein,wereport a new synthetic strategy,named the Kirkendall effect in synergistic template(KEST),for the desired preparation of hollow mesoporous palladium–sulfur(h-mesoPdS)alloy nanoparticles.展开更多
Cu-incorporated ordered hexagonal mesoporous silicates （Cu-MCM-41） with spheres-within-a-sphere hollow structure have been synthesized using thermoreversible polymer hydrogel methylcellulose （MC） and cationic surf...Cu-incorporated ordered hexagonal mesoporous silicates （Cu-MCM-41） with spheres-within-a-sphere hollow structure have been synthesized using thermoreversible polymer hydrogel methylcellulose （MC） and cationic surfactant as co-templates, which have been characterized by scanning electron micrograph （SEM）, X-ray diffraction （XRD）, transmission electron micrograph （TEM）, and N2 adsorption-desorption isotherms. The obtained results indicate that the morphology of Cu-incorporated MCM-41 materials is ＂spheres-within-a-sphere＂ hollow structure, which is very similar to that of the alveolus. In benzene hydroxylation with H2O2, the hollow spheres show much higher catalytic activity than particles of Cu-MCM-41.展开更多
Heteroatom-doped porous carbon materials are very attractive for lithium ion batteries(LIBs) owing to their high specific surface areas, open pore structures, and abundant active sites. However, heteroatomdoped porous...Heteroatom-doped porous carbon materials are very attractive for lithium ion batteries(LIBs) owing to their high specific surface areas, open pore structures, and abundant active sites. However, heteroatomdoped porous carbon with very high surface area and large pore volume are highly desirable but still remain a big challenge. Herein, we reported a sulfur-doped mesoporous carbon(CMK-5-S) with nanotubes array structure, ultrahigh specific surface area(1390 m^(2)/g), large pore volume(1.8 cm^(3)/g), bimodal pore size distribution(2.9 and 4.6 nm), and high sulfur content(2.5 at%). The CMK-5-S used as an anode material for LIBs displays high specific capacity, excellent rate capability and highly cycling stability. The initial reversible specific capacity at 0.1 A/g is as high as 1580 mAh/g and simultaneously up to 701 mAh/g at 1A/g even after 500 cycles. Further analysis reveals that the excellent electrochemical storage performances is attributed to its unique structures as well as the expanded lattice by sulfur-doping.展开更多
基金Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2019R1A2C2088047 and NRF-2020R1C1C1003375).
文摘In this work,a novel vacuum-assisted strategy is proposed to homogenously form Metal-organic frameworks within hollow mesoporous carbon nanospheres(HMCSs)via a solid-state reaction.The method is applied to synthesize an ultrafine CoSe2 nanocrystal@N-doped carbon matrix confined within HMCSs(denoted as CoSe2@NC/HMCS)for use as advanced anodes in highperformance potassium-ion batteries(KIBs).The approach involves a solvent-free thermal treatment to form a Co-based zeolitic imidazolate framework(ZIF-67)within the HMCS templates under vacuum conditions and the subsequent selenization.Thermal treatment under vacuum facilitates the infiltration of the cobalt precursor and organic linker into the HMCS and simultaneously transforms them into stable ZIF-67 particles without any solvents.During the subsequent selenization process,the“dual confinement system”,composed of both the N-doped carbon matrix derived from the organic linker and the small-sized pores of HMCS,can effectively suppress the overgrowth of CoSe2 nanocrystals.Thus,the resulting uniquely structured composite exhibits a stable cycling performance(442 mAh g^−1 at 0.1 A g^−1 after 120 cycles)and excellent rate capability(263 mAh g^−1 at 2.0 A g^−1)as the anode material for KIBs.
基金sponsored by the Program for New Century Excellent Talents in the University(No.NCET-04-0268)by the 111 Project.
文摘Micron-sized hollow silica spheres whose shells are made up of mesocellular silica foams （MCFs） have been synthesized by one-pot sol-gel method in benzene/water/P123 emulsion. The material is characterized with SEM, TEM, BET and ^29Si MAS NMR. The results show that the MCFs of the unique shell of hollow silica spheres were connected by large windows with a narrow distribution of - 10 nm in diameter, the inner space of the hollow sphere is accessible. And the formation mechanism of the hollow silica spheres is proposed. C 2009 Xin Wen Guo. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金This work was supported by the National Key R&D Program of China(Nos.2022YFA1503501 and 2018YFA0209401)the National Natural Science Foundation of China(Nos.22088101,21975050 and U21A20329)+2 种基金the Program of Shanghai Academic Research Leader(No.21XD1420800)the Shanghai Pilot Program for Basic Research-Fudan University 21TQ1400100(No.21TQ008)the Fundamental Research Funds for the Central Universities(No.20720220010).
文摘The selective hydrogenolysis of glycerol exhibits great prospects,while the catalysts with high selectivity and activity are still missing and need to be created urgently.Herein,we report the synthesis of hollow mesoporous Pt/WO_(x)/SiO_(2)-TiO_(2)nanosphere catalysts with bi-functional interfaces synergistically for high efficiency conversion of glycerol to 1,3-propanediol.The hollow mesoporous Pt/WO_(x)/SiO_(2)-TiO_(2)catalysts show a typical brick-concrete liked framework with a high surface area(179.3 m^(2)·g^(-1)),large mesopore size(10.6 nm),uniform particle size(~400 nm),and ultrathin shell thickness(~75 nm).The brick anatase nanocrystals and concrete amorphous SiO_(2)networks can selectively rivet Pt nanoparticles and WO_(x)nanocluster species,respectively,thus constructing two interfaces for effective adsorption,rapidly catalytic dehydration and hydrogenation processes.The hollow mesoporous Pt/WO_(x)/SiO_(2)-TiO_(2)catalysts deliver a high selectivity of 53.8%for 1,3-propanediol(1,3-PDO)at a very high glycerol conversion of 85.0%.As a result,a favorable 1,3-PDO yield of 45.7%can be obtained with excellent stability,which is among the best performances of previously reported catalysts.This work paves a new way to synthesize catalysts with high selectivity,high activity and high stability.
基金supported by the National Natural Science Foundation of China(Nos.21671073 and 21621001)the“111”Project of the Ministry of Education of China(No.B17020)Program for JLU Science and Technology Innovative Research Team。
文摘Nowadays,multi-shelled mesoporous hollow metal oxide nanospheres have drawn a lot of attention due to their large internal space,nanometer scaled shell thickness,high specific surface area and well-defined mesopores,of which unique nanostructure endows metallic oxides with enhanced properties.In this thesis,we have studied and proposed a versatile ligand-assisted cooperative template method to synthesize multi-shelled mesoporous hollow metal hydroxides and oxides nanospheres,in which silica nanospheres act as sacrificial templates and the coordination interaction between metal ions and surfactant can be cooperatively amplified by using chelating ligand(ascorbic acid)as a co-template.The synthesized metal hydroxides and oxides nanospheres possess stable hollow structure,uniform spherical morphology and tunable diameter from 270 to 690 nm.All the multi-shelled mesoporous hollow metal hydroxide and metal oxide nanospheres exhibit high surface areas(up to 640 m^(2)/g).The obtained Au nanoparticles loaded composited nanospheres exhibit excellent reactivity for solvent-free aerobic oxidation of ethylbenzene with high activity(28.2%)and selectivity(87%).
基金acknowledge the National Key R&D Program of China(no.2018YFE0201701)the Natural Science Foundation of China(grant nos.21975050 and 21771156)+2 种基金the Natural Science Foundation of Jiangsu Province(no.BK20191366)the Open Project of State Key Laboratory of Supramolecular Structure and Materials(no.sklssm2021011)the Fundamental Research Funds for the Central Universities for financial support.
文摘Hollow mesoporous metals have unique potential for catalysis,but their precise synthesis and further elaboration of their structure–performance relationships are still huge challenges.Herein,wereport a new synthetic strategy,named the Kirkendall effect in synergistic template(KEST),for the desired preparation of hollow mesoporous palladium–sulfur(h-mesoPdS)alloy nanoparticles.
基金Project supported by the National Natural Science Foundation of China, the Major State Basic Research Development Program of China （Nos. 2004CB217804 and 2003CB615802）, and Ministry of Education, China.
文摘Cu-incorporated ordered hexagonal mesoporous silicates （Cu-MCM-41） with spheres-within-a-sphere hollow structure have been synthesized using thermoreversible polymer hydrogel methylcellulose （MC） and cationic surfactant as co-templates, which have been characterized by scanning electron micrograph （SEM）, X-ray diffraction （XRD）, transmission electron micrograph （TEM）, and N2 adsorption-desorption isotherms. The obtained results indicate that the morphology of Cu-incorporated MCM-41 materials is ＂spheres-within-a-sphere＂ hollow structure, which is very similar to that of the alveolus. In benzene hydroxylation with H2O2, the hollow spheres show much higher catalytic activity than particles of Cu-MCM-41.
基金funding from the National Key R&D Program of China (No. 2018YFE0201703)the National Natural Science Foundation of China (Nos. 22272120, U2202251)the “1000-Youth Talents Plan”。
文摘Heteroatom-doped porous carbon materials are very attractive for lithium ion batteries(LIBs) owing to their high specific surface areas, open pore structures, and abundant active sites. However, heteroatomdoped porous carbon with very high surface area and large pore volume are highly desirable but still remain a big challenge. Herein, we reported a sulfur-doped mesoporous carbon(CMK-5-S) with nanotubes array structure, ultrahigh specific surface area(1390 m^(2)/g), large pore volume(1.8 cm^(3)/g), bimodal pore size distribution(2.9 and 4.6 nm), and high sulfur content(2.5 at%). The CMK-5-S used as an anode material for LIBs displays high specific capacity, excellent rate capability and highly cycling stability. The initial reversible specific capacity at 0.1 A/g is as high as 1580 mAh/g and simultaneously up to 701 mAh/g at 1A/g even after 500 cycles. Further analysis reveals that the excellent electrochemical storage performances is attributed to its unique structures as well as the expanded lattice by sulfur-doping.
