Incorporating a selenium(Se)positive electrode into aluminum(Al)-ion batteries is an effective strategy for improving the overall battery performance.However,the cycling stability of Se positive electrodes has challen...Incorporating a selenium(Se)positive electrode into aluminum(Al)-ion batteries is an effective strategy for improving the overall battery performance.However,the cycling stability of Se positive electrodes has challenges due to the dissolution of intermediate reaction products.In this work,we aim to harness the advantages of Se while reducing its limitations by preparing a core-shell mesoporous carbon hollow sphere with a titanium nitride(C@TiN)host to load 63.9wt%Se as the positive electrode material for Al-Se batteries.Using the physical and chemical confinement offered by the hollow mesoporous carbon and TiN,the obtained core-shell mesoporous carbon hollow spheres coated with Se(Se@C@TiN)display superior utilization of the active material and remarkable cycling stability.As a result,Al-Se batteries equipped with the as-prepared Se@C@TiN composite positive electrodes show an initial discharge specific capacity of 377 mAh·g^(-1)at a current density of 1000 mA·g^(-1)while maintaining a discharge specific capacity of 86.0 mAh·g^(-1)over 200 cycles.This improved cycling performance is ascribed to the high electrical conductivity of the core-shell mesoporous carbon hollow spheres and the unique three-dimensional hierarchical architecture of Se@C@TiN.展开更多
The triple-shelled hollow spheres with optical properties were prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization.After removal the core templates of the poly(styrene),the hollow silic...The triple-shelled hollow spheres with optical properties were prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization.After removal the core templates of the poly(styrene),the hollow silica spheres were obtained.The coating process of poly(methyl methacrylate)(PMMA) on the hollow silica spheres surface via surface RAFT polymerization was performed subsequently.The polymers coated on the hollow spheres surfaces were end-functionalized by trithiocarbonate,and they were used as RAFT agent to proceed the chain extension polymerization using Tb complex as monomer.The samples were characterized by FT-IR,SEM and luminescence spectroscopy respectively.The results indicated that the triple-shelled hollow spheres had been prepared successfully and the average diameter of the hollow core was about 1μm.展开更多
Abstract: We performed fluidized bed coating ofAl-based nanoeomposite powder-binder suspensions onto polymer substrates. The effects of the type and amount of the binder and nanoparticle additive on the coating proce...Abstract: We performed fluidized bed coating ofAl-based nanoeomposite powder-binder suspensions onto polymer substrates. The effects of the type and amount of the binder and nanoparticle additive on the coating process efficiency and coating characteristics were investigated. The efficiency decreased from 52% to 49% as the processing time increased from 15 to 20 min. However, the amount and thickness of the coating also increased as the processing time and amount of the binder were increased. The addition of nanoparticles to the system decreased the thickness of the coating from 222 to 207 μm when polyvinyl alcohol (PVA) was used as a binder. The suspension containing 3wt% R-4410 binder exhibited the greatest efficiency of 60%.展开更多
TiO2-coated SnO2 (TCS) hollow spheres, which are new anode materials for lithium ion (Li-ion) batteries, were prepared and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transm...TiO2-coated SnO2 (TCS) hollow spheres, which are new anode materials for lithium ion (Li-ion) batteries, were prepared and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), and galvanostatic charge/discharge tests. The results obtained from XRD, SEM, and TEM show that TiO2 can be uniforrrdy coated on the surface of SnO2 hollow spheres with the assistance of anionic surfactant. The cyclic voltammograms indicate that both TiO2 and SnO2 exhibit the activity for Li-ion storage. The charge/discharge tests show that the prepared TCS hollow spheres have a higher reversible coulomb efficiency and a better cycling stability than the uncoated SnO2 hollow spheres.展开更多
CaCO3 hollow spheres were prepared easily in anion surfactants (sodium dodecylbenzenesulfonate (SDBS)) and aspartic (Asp) acid binary-additive system by using an easy rapid agitation method. The as-prepared prod...CaCO3 hollow spheres were prepared easily in anion surfactants (sodium dodecylbenzenesulfonate (SDBS)) and aspartic (Asp) acid binary-additive system by using an easy rapid agitation method. The as-prepared products were characterized with scanning electron microscopy (SEM), FT-IR and X-ray diffraction. The results suggested that the CaCO3 hollow spheres have diameters ranging from 1 to 2 μm, and their wall is constituted of many nano-particles. Moreover, the possible formation mechanism of the hollow spherical structure was proposed.展开更多
A series of basic nitrogen doped carbon hollow spheres(p-N-C) catalysts derived from waste tires were prepared by a green, facile and environmental “leavening” strategy for the catalytic oxidation of pentanethiol. C...A series of basic nitrogen doped carbon hollow spheres(p-N-C) catalysts derived from waste tires were prepared by a green, facile and environmental “leavening” strategy for the catalytic oxidation of pentanethiol. Compared to pristine carbon, the p-N-C has a higher surface curvature conducive to the enrichment of substrates, leading to an excellent catalytic performance. This increased surface curvature of p-N-C was fabricated on the synergistic effect of two foaming agents((NH4)2 C2 O4 and NaHCO3), and the released gas also endows the spherical shell of p-N-C with a hierarchical porous structure, promoting the accessibility of active sites with pentanethiol. Pyridine-like and pyrrolic-like nitrogen atoms were investigated as reactive sites on the p-N-C to accelerate the electron transfer from sulfur to active surface oxygen and enhance the adsorption/oxidation process. As a result, the optimal p-N-C catalyst exhibits superior adsorption and oxidation performance(99.9%) of pentanethiol, outperforming the “unleavened”catalyst(20.8%). This work offers a new avenue for the fabrication of highly efficient materials for the desulfurization of fuel.展开更多
Nanocrystalline MoS2 with hollow spherical morphology has been prepared by the hydrothermal method. The products are characterized by means of X-ray powder diffraction, transmission electron microscopy and high-resol...Nanocrystalline MoS2 with hollow spherical morphology has been prepared by the hydrothermal method. The products are characterized by means of X-ray powder diffraction, transmission electron microscopy and high-resolution transmission electron microscopy. The experimental results give the evidence that the sample is consists of hollow spheres 400~600 nm in diameter, and there is much whisker on the surface of MoS2 hollow sphere.展开更多
The ternary transitional metal oxide NiCo_2O_4 is a promising anode material for sodium ion batteries due to its high theoretical capacity and superior electrical conductivity. However, its sodium storage capability i...The ternary transitional metal oxide NiCo_2O_4 is a promising anode material for sodium ion batteries due to its high theoretical capacity and superior electrical conductivity. However, its sodium storage capability is severely limited by the sluggish sodiation/desodiation reaction kinetics. Herein, NiCo_2O_4 double-shelled hollow spheres were synthesized via a microwave-assisted, fast solvothermal synthetic procedure in a mixture of isopropanol and glycerol, followed by annealing. Isopropanol played a vital role in the precipitation of nickel and cobalt,and the shrinkage of the glycerol quasi-emulsion under heat treatment was responsible for the formation of the double-shelled nanostructure. The as-synthesized productwas tested as an anode material in a sodium ion battery,was found to exhibit a high reversible specific capacity of 511 m Ahg^(-1) at 100 m Ag^(-1), and deliver high capacity retention after 100 cycles.展开更多
Catalyst support is extremely important for future fuel cell devices.In this work,we developed doubleshelled C/TiO2(DSCT)hollow spheres as an excellent catalyst support via a template-directed method.The combination o...Catalyst support is extremely important for future fuel cell devices.In this work,we developed doubleshelled C/TiO2(DSCT)hollow spheres as an excellent catalyst support via a template-directed method.The combination of hollow structure,TiO2 shell and carbon layer results in excellent electron conductivity,electrocatalytic activity,and chemical stability.These uniformed DSCT hollow spheres are used as catalyst support to synthesize Pt/DSCT hollow spheres electrocatalyst.The resulting Pt/DSCT hollow spheres exhibited high catalytic performance with a current density of 462 mA mg^-1 for methanol oxidation reaction,which is 2.52 times higher than that of the commercial Pt/C.Furthermore,the increased tolerance to carbonaceous poisoning with a higher If/Ibratio and a better long-term stability in acid media suggests that the DSCT hollow sphere is a promising C/TiO2-based catalyst support for direct methanol fuel cells applications.展开更多
Monoclinic Cu3V2O7(OH)2·2H2O(copper polyvanadate) hollow spheres were prepared with Na2V6O16·3H2O nanobelts as V-precursor by hydrothermal method. The purity and structure of the products were characteri...Monoclinic Cu3V2O7(OH)2·2H2O(copper polyvanadate) hollow spheres were prepared with Na2V6O16·3H2O nanobelts as V-precursor by hydrothermal method. The purity and structure of the products were characterized by X-ray powder diffraction(XRD), Fourier transform infrared(FTIR) spectroscopy, Raman spectroscopy, thermogravimetric analysis(TGA) and X-ray photoelecton spectroscopy(XPS). The morphology and size were observed by scanning electron microscopy(SEM). We found that the Kagomé staircase-structural copper polyvanadate hollow spheres with an average diameter of 7 μm could be easily synthesized via the reaction of Na2V6O16·3H2O nanobelts with sufficient copper sulfate. The dielectric property of the copper polyvanadate demonstrates that dielectric loss hardly changes when the frequency of applied electric field is higher than 100 kHz. The formation process of the hollow spheres is discussed in detail by the observation of a series of products prepared for different reaction time.展开更多
The unsatisfactory conductivity and large volume variation severely handicap the application of SnO_(2)in sodium-ion batteries(SIBs).Herein,we design unique three-layer structured SnO_(2)@C@TiO_(2)hollow spheres to ta...The unsatisfactory conductivity and large volume variation severely handicap the application of SnO_(2)in sodium-ion batteries(SIBs).Herein,we design unique three-layer structured SnO_(2)@C@TiO_(2)hollow spheres to tackle the above-mentioned issues.The hollow cavity affords empty space to accommodate the volume variation of SnO_(2),while the C and TiO_(2)protecting shells strengthen the structural integrity and enhances the electrical conductivity.As a result,the three-layer structured SnO_(2)@C@TiO_(2)hollow spheres demonstrate enhanced Na storage performances.The SnO_(2)@C@TiO_(2)manifests a reversible capacity two times to that of pristine SnO_(2)hollow spheres.In addition,Ex situ XRD reveals highly reversible alloying and conversion reactions in SnO_(2)@C@TiO_(2)hollow spheres.This study suggests the introduction of a hollow cavity and robust protecting shells is a promising strategy for constructing SIB anode materials.展开更多
Zirconia hollow sphere products are ultra-high temperature energy saving lightweight insulating refractories in zirconia system.They not only have the same refractoriness as zirconia products,but also have the advanta...Zirconia hollow sphere products are ultra-high temperature energy saving lightweight insulating refractories in zirconia system.They not only have the same refractoriness as zirconia products,but also have the advantages of low bulk density and excellent thermal insulation properties.Their thermal conductivity is 0.3-0.4 W · m-1 · K-1 only 1/2 of that of the ordinary zirconia products.They are special refractories which can be used steadily up to 2 400 ℃ in oxidation,reduction and vacuum atmospheres.Zirconia hollow sphere products are the best lining refractories for various ultra-high temperature kilns and furnaces of tungsten and molybdenum metal products processing,artificial crystals,and quartz industrial production.展开更多
β-SiAION hollow spheres were prepared by carbothermal reduction method, using coal fly ash ( 〈 15 μm, 43 - 77 μm, and 〉 100 μm) and active carbon in Some proportion (20% less than theoretical addition, theore...β-SiAION hollow spheres were prepared by carbothermal reduction method, using coal fly ash ( 〈 15 μm, 43 - 77 μm, and 〉 100 μm) and active carbon in Some proportion (20% less than theoretical addition, theoretical addition and 10% excess theoretical addition) as starting materials, putting into alumina crucible in high temperature nitriding furnace after well mixed, and holding at 1 300 ℃, 1 350 ℃, 1 400 ℃, 1 450 ℃, and 1 500 ℃ for 6 h. Effects of temperature, particle size of the microsphere . and addition of active carbon on the phase composition and microstructure of the nitridized products were studied by means of XRD and SEM. The results show that the nitridation reaction starts at 1 300 ℃ ; excess active carbon is necessary to form β-SiAION hollow spheres, and particle size is the important parameter to form the hollow spheres nitridized products β-SiAION; at 1 500 ℃, when the active carbon is 10% in excess, the β-SiAlON hollow spheres, which were prepared using coal fly ash with particle size 〉 100 μm, are featured with rough surface, high hollowness and low density.展开更多
High-performance and low-cost gas sensors are highly desirable and involved in industrial production and environmental detection.The combination of highly conductive MXene and metal oxide materials is a promising stra...High-performance and low-cost gas sensors are highly desirable and involved in industrial production and environmental detection.The combination of highly conductive MXene and metal oxide materials is a promising strategy to further improve the sensing performances.In this study,the hollow SnO_(2)nanospheres and few-layer MXene are assembled rationally via facile electrostatic synthesis processes,then the SnO_(2)/Ti_(3)C_(2)T_(x)nanocomposites were obtained.Compared with that based on either pure SnO_(2)nanoparticles or hollow nanospheres of SnO_(2),the SnO_(2)/Ti_(3)C_(2)T_(x)composite-based sensor exhibits much better sensing performances such as higher response(36.979),faster response time(5 s),and much improved selectivity as well as stability(15 days)to 100ppm C2H5OH at low working temperature(200°C).The improved sensing performances are mainly attributed to the large specific surface area and significantly increased oxygen vacancy concentration,which provides a large number of active sites for gas adsorption and surface catalytic reaction.In addition,the heterostructure interfaces between SnO_(2)hollow spheres and MXene layers are beneficial to gas sensing behaviors due to the synergistic effect.展开更多
Mesoporous silica hollow spheres with a homogenous and high content distribution of Fe and Co were synthesized by a facile one-pot hydrothermal process. The sub-nanometer bimetallic components inside the silica framew...Mesoporous silica hollow spheres with a homogenous and high content distribution of Fe and Co were synthesized by a facile one-pot hydrothermal process. The sub-nanometer bimetallic components inside the silica framework facilitate the stable fixation and the open accessibility to active sites. The co-doped Fe/Co in the spheres showed excellent peroxidase-like activity and much higher catalytic performance than their monometallic-supported spheres. The synergistic effect between Fe and Co promotes the continuous formation of functional radicals during the oxidation process and thus accelerates the reaction rate. When used for colorimetric detection of hydrogen peroxide(H_(2)O_(2)), the Fe/Co incorporated silica hollow spheres show the capability of detection of H_(2)O_(2) in a wide range(10-250 μmol/L) and with the low detection limit of 0.012 ppm.展开更多
The strong metal-support interaction inducing combined effect plays a crucial role in the catalysis reaction. Herein, we revealed that the combined advantages of MoSe_(2), Ru, and hollow carbon spheres in the form of ...The strong metal-support interaction inducing combined effect plays a crucial role in the catalysis reaction. Herein, we revealed that the combined advantages of MoSe_(2), Ru, and hollow carbon spheres in the form of Ru nanoparticles(NPs) anchored on a two-dimensionally ordered MoSe_(2) nanosheet-embedded mesoporous hollow carbon spheres surface(Ru/MoSe_(2)@MHCS) for the largely boosted hydrogen evolution reaction(HER) performance. The combined advantages from the conductive support, oxyphilic MoSe_(2), and Ru active sites imparted a strong synergistic effect and charge redistribution in the Ru periphery which induced high catalytic activity, stability, and kinetics for HER. Specifically, the obtained Ru/MoSe_(2)@MHCS required a small overpotential of 25.5 and 38.4 mV to drive the kinetic current density of 10 mA cm^(-2)both in acid and alkaline media, respectively, which was comparable to that of the Pt/C catalyst. Experimental and theoretical results demonstrated that the charge transfer from MoSe_(2) to Ru NPs enriched the electronic density of Ru sites and thus facilitated hydrogen adsorption and water dissociation. The current work showed the significant interfacial engineering in Ru-based catalysts development and catalysis promotion effect understanding via the metal-support interaction.展开更多
CeO_2 hollow spheres were synthesized by polystryrene sphere(PS) templates and CeO_2 nanoparticles were prepared by a facile method. The as-obtained products were characterized by scanning electron microscopy(SEM)...CeO_2 hollow spheres were synthesized by polystryrene sphere(PS) templates and CeO_2 nanoparticles were prepared by a facile method. The as-obtained products were characterized by scanning electron microscopy(SEM), N_2 adsorption-desorption, X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR) and UV-vis diffuse reflectance spectra. The results showed that the structure of the obtained CeO_2 hollow spheres was hollow microsphere with a diameter of 380 nm and the average particle size of CeO_2 nanoparticles was about 1700 nm. The two samples' Brunauer-Emmett-Teller(BET) surface area was 67.1 and 37.2 m^2/g. The CeO_2 hollow spheres had a better performance than nanoparticles at UV-shielding because of higher surface area and the structure of hollow sphere.展开更多
A strategy of intensifying the visible light harvesting ability of anatase Ti02 hollow spheres(HSs)was developed,in which both sides of Ti02 HSs were utilised for stabilising Au nanoparticles(NPs)through the sacrifici...A strategy of intensifying the visible light harvesting ability of anatase Ti02 hollow spheres(HSs)was developed,in which both sides of Ti02 HSs were utilised for stabilising Au nanoparticles(NPs)through the sacrificial templating method and convex surface-induced confinement.The composite structure of single Au NP yolk-Ti02 shell-Au NPs,denoted as Au@Au(Ti02,was rendered and confirmed by the transmission electron microscopy analysis.Au@Au(Ti02 showed enhanced photocatalytic activity in the degradation of methylene blue and phenol in aqueous phase under visible light surpassing that of other reference materials such as Au(Ti02 by 77%and Au@P25 by 52%,respectively,in phenol degradation.展开更多
Recently, researchers have focused on designing and fabricating highly efficient catalysts for photocatalytic organic pollutant removal. Herein, CeO_(2) hollow spheres were prepared through a simple template method fo...Recently, researchers have focused on designing and fabricating highly efficient catalysts for photocatalytic organic pollutant removal. Herein, CeO_(2) hollow spheres were prepared through a simple template method followed by calcination at different temperatures for the tetracycline(TC) degradation under simulated solar light illumination. With a calcination temperature ranging from400 to 800 ℃, the as-prepared CeO_(2) hollow structure annealed at 600 ℃(C_(600)) exhibited the best degradation performance with a degradation rate constant of0.066 min-1, which was about six and five times higher than those of the uncalcined sample(C_(0)) and the sample calcined at 800 ℃(C_(800)), respectively. Moreover, sample C_(600)was also superior to the CeO_(2) solid particle photocatalyst. The characterisation results showed that the improved photocatalytic performance was mainly ascribed to the synergistic effect of large specific surface areas, high crystallisation and excellent light scattering ability. Furthermore, the results of active species trapping experiments demonstrated that the superoxide anion(·O_(2)^(-)) radical and hole(h^(+)) played dominant roles in TC degradation. Subsequently, the possible TC degradation pathways and photocatalytic mechanism of CeO_(2) hollow spheres were proposed on the basis of high-performance liquid chromatography–mass spectrometry analysis, main active species and band edge positions of CeO_(2). The results of this study provide a basis for designing and exploring hollow structure catalysts for energy conversion and environmental remediation.展开更多
MoS_2 has attracted attention as a promising hydrogen evolution reaction(HER) catalyst and a supercapacitor electrode material. However, its catalytic activity and capacitive performance are still hindered by its aggr...MoS_2 has attracted attention as a promising hydrogen evolution reaction(HER) catalyst and a supercapacitor electrode material. However, its catalytic activity and capacitive performance are still hindered by its aggregation and poor intrinsic conductivity. Here, hollow rGO sphere-supported ultrathin MoS_2 nanosheet arrays(hrGO@MoS_2) are constructed via a dual-template approach and employed as bifunctional HER catalyst and supercapacitor electrode material. Because of the expanded interlayer spacing in MoS_2 nanosheets and more exposed electroactive S–Mo–S edges, the constructed h-rGO@MoS_2 architectures exhibit enhanced HER performance. Furthermore, benefiting from the synergistic effect of the improved conductivity and boosted specific surface areas(144.9 m^2 g^(-1), ca. 4.6-times that of pristine MoS_2), the h-rGO@MoS_2 architecture shows a high specific capacitance(238 F g^(-1) at a current density of 0.5 A g^(-1)), excellent rate capacitance, and remarkable cycle stability. Our synthesis method may be extended to construct other vertically aligned hollow architectures,which may serve both as efficient HER catalysts and supercapacitor electrodes.展开更多
基金supported by the National Natural Science Foundation of China(No.52374350)China Postdoctoral Science Foundation(Nos.2020M680347 and 2021T140051)the Fundamental Research Funds for the Central Universities(No.FRF-TP-20-045A1)。
文摘Incorporating a selenium(Se)positive electrode into aluminum(Al)-ion batteries is an effective strategy for improving the overall battery performance.However,the cycling stability of Se positive electrodes has challenges due to the dissolution of intermediate reaction products.In this work,we aim to harness the advantages of Se while reducing its limitations by preparing a core-shell mesoporous carbon hollow sphere with a titanium nitride(C@TiN)host to load 63.9wt%Se as the positive electrode material for Al-Se batteries.Using the physical and chemical confinement offered by the hollow mesoporous carbon and TiN,the obtained core-shell mesoporous carbon hollow spheres coated with Se(Se@C@TiN)display superior utilization of the active material and remarkable cycling stability.As a result,Al-Se batteries equipped with the as-prepared Se@C@TiN composite positive electrodes show an initial discharge specific capacity of 377 mAh·g^(-1)at a current density of 1000 mA·g^(-1)while maintaining a discharge specific capacity of 86.0 mAh·g^(-1)over 200 cycles.This improved cycling performance is ascribed to the high electrical conductivity of the core-shell mesoporous carbon hollow spheres and the unique three-dimensional hierarchical architecture of Se@C@TiN.
基金a project of Shandong Province Higher Education Science and Technology Program(No.J09LD56)the Scientific Research Start up Fund for Doctor of Liaocheng University.
文摘The triple-shelled hollow spheres with optical properties were prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization.After removal the core templates of the poly(styrene),the hollow silica spheres were obtained.The coating process of poly(methyl methacrylate)(PMMA) on the hollow silica spheres surface via surface RAFT polymerization was performed subsequently.The polymers coated on the hollow spheres surfaces were end-functionalized by trithiocarbonate,and they were used as RAFT agent to proceed the chain extension polymerization using Tb complex as monomer.The samples were characterized by FT-IR,SEM and luminescence spectroscopy respectively.The results indicated that the triple-shelled hollow spheres had been prepared successfully and the average diameter of the hollow core was about 1μm.
文摘Abstract: We performed fluidized bed coating ofAl-based nanoeomposite powder-binder suspensions onto polymer substrates. The effects of the type and amount of the binder and nanoparticle additive on the coating process efficiency and coating characteristics were investigated. The efficiency decreased from 52% to 49% as the processing time increased from 15 to 20 min. However, the amount and thickness of the coating also increased as the processing time and amount of the binder were increased. The addition of nanoparticles to the system decreased the thickness of the coating from 222 to 207 μm when polyvinyl alcohol (PVA) was used as a binder. The suspension containing 3wt% R-4410 binder exhibited the greatest efficiency of 60%.
基金financially supported by the National Natural Science Foundation of China (No.20873046)the Specialized Research Fund for the Doctoral Program of HigherEducation (No.200805740004)Natural Science Foundation of Guangdong Province (No.10351063101000001)
文摘TiO2-coated SnO2 (TCS) hollow spheres, which are new anode materials for lithium ion (Li-ion) batteries, were prepared and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), and galvanostatic charge/discharge tests. The results obtained from XRD, SEM, and TEM show that TiO2 can be uniforrrdy coated on the surface of SnO2 hollow spheres with the assistance of anionic surfactant. The cyclic voltammograms indicate that both TiO2 and SnO2 exhibit the activity for Li-ion storage. The charge/discharge tests show that the prepared TCS hollow spheres have a higher reversible coulomb efficiency and a better cycling stability than the uncoated SnO2 hollow spheres.
基金sponsored by the National Natural Science Foundation of China (No. 20171001)Natural Science Foundation of Anhui Provincial Department of Education (No. 2005KJ369ZC)
文摘CaCO3 hollow spheres were prepared easily in anion surfactants (sodium dodecylbenzenesulfonate (SDBS)) and aspartic (Asp) acid binary-additive system by using an easy rapid agitation method. The as-prepared products were characterized with scanning electron microscopy (SEM), FT-IR and X-ray diffraction. The results suggested that the CaCO3 hollow spheres have diameters ranging from 1 to 2 μm, and their wall is constituted of many nano-particles. Moreover, the possible formation mechanism of the hollow spherical structure was proposed.
基金financially supported by the National Natural Science Foundation of China (Nos. 21722604, 21878133, and22002050)China Postdoctoral Science Foundation (No.2020M671365)Postgraduate Research&Practice Innovation Program of Jiangsu Province (No. KYCX20_3039)。
文摘A series of basic nitrogen doped carbon hollow spheres(p-N-C) catalysts derived from waste tires were prepared by a green, facile and environmental “leavening” strategy for the catalytic oxidation of pentanethiol. Compared to pristine carbon, the p-N-C has a higher surface curvature conducive to the enrichment of substrates, leading to an excellent catalytic performance. This increased surface curvature of p-N-C was fabricated on the synergistic effect of two foaming agents((NH4)2 C2 O4 and NaHCO3), and the released gas also endows the spherical shell of p-N-C with a hierarchical porous structure, promoting the accessibility of active sites with pentanethiol. Pyridine-like and pyrrolic-like nitrogen atoms were investigated as reactive sites on the p-N-C to accelerate the electron transfer from sulfur to active surface oxygen and enhance the adsorption/oxidation process. As a result, the optimal p-N-C catalyst exhibits superior adsorption and oxidation performance(99.9%) of pentanethiol, outperforming the “unleavened”catalyst(20.8%). This work offers a new avenue for the fabrication of highly efficient materials for the desulfurization of fuel.
基金This work was supported by the National Natural Science Foundation of China.
文摘Nanocrystalline MoS2 with hollow spherical morphology has been prepared by the hydrothermal method. The products are characterized by means of X-ray powder diffraction, transmission electron microscopy and high-resolution transmission electron microscopy. The experimental results give the evidence that the sample is consists of hollow spheres 400~600 nm in diameter, and there is much whisker on the surface of MoS2 hollow sphere.
基金financially supported by the Science Foundation of Sichuan Province(Grant No.2016FZ0070)the Natural Science Foundation of China(NSFC,201476145)the technical support for Materials Characterization from The Analytical and Testing Center of Sichuan University
文摘The ternary transitional metal oxide NiCo_2O_4 is a promising anode material for sodium ion batteries due to its high theoretical capacity and superior electrical conductivity. However, its sodium storage capability is severely limited by the sluggish sodiation/desodiation reaction kinetics. Herein, NiCo_2O_4 double-shelled hollow spheres were synthesized via a microwave-assisted, fast solvothermal synthetic procedure in a mixture of isopropanol and glycerol, followed by annealing. Isopropanol played a vital role in the precipitation of nickel and cobalt,and the shrinkage of the glycerol quasi-emulsion under heat treatment was responsible for the formation of the double-shelled nanostructure. The as-synthesized productwas tested as an anode material in a sodium ion battery,was found to exhibit a high reversible specific capacity of 511 m Ahg^(-1) at 100 m Ag^(-1), and deliver high capacity retention after 100 cycles.
基金supported by the Scholarship from China Scholarship Council(CSC)(Grant no.201604910621)。
文摘Catalyst support is extremely important for future fuel cell devices.In this work,we developed doubleshelled C/TiO2(DSCT)hollow spheres as an excellent catalyst support via a template-directed method.The combination of hollow structure,TiO2 shell and carbon layer results in excellent electron conductivity,electrocatalytic activity,and chemical stability.These uniformed DSCT hollow spheres are used as catalyst support to synthesize Pt/DSCT hollow spheres electrocatalyst.The resulting Pt/DSCT hollow spheres exhibited high catalytic performance with a current density of 462 mA mg^-1 for methanol oxidation reaction,which is 2.52 times higher than that of the commercial Pt/C.Furthermore,the increased tolerance to carbonaceous poisoning with a higher If/Ibratio and a better long-term stability in acid media suggests that the DSCT hollow sphere is a promising C/TiO2-based catalyst support for direct methanol fuel cells applications.
基金Supported by the "973" Basic Research Foundation of China(No.2006CB932605)the National Natural Science Founda-tion of China(No.20876002).
文摘Monoclinic Cu3V2O7(OH)2·2H2O(copper polyvanadate) hollow spheres were prepared with Na2V6O16·3H2O nanobelts as V-precursor by hydrothermal method. The purity and structure of the products were characterized by X-ray powder diffraction(XRD), Fourier transform infrared(FTIR) spectroscopy, Raman spectroscopy, thermogravimetric analysis(TGA) and X-ray photoelecton spectroscopy(XPS). The morphology and size were observed by scanning electron microscopy(SEM). We found that the Kagomé staircase-structural copper polyvanadate hollow spheres with an average diameter of 7 μm could be easily synthesized via the reaction of Na2V6O16·3H2O nanobelts with sufficient copper sulfate. The dielectric property of the copper polyvanadate demonstrates that dielectric loss hardly changes when the frequency of applied electric field is higher than 100 kHz. The formation process of the hollow spheres is discussed in detail by the observation of a series of products prepared for different reaction time.
基金financially supported by Shenzhen Fundamental Research Program(JCYJ20190809114409397)
文摘The unsatisfactory conductivity and large volume variation severely handicap the application of SnO_(2)in sodium-ion batteries(SIBs).Herein,we design unique three-layer structured SnO_(2)@C@TiO_(2)hollow spheres to tackle the above-mentioned issues.The hollow cavity affords empty space to accommodate the volume variation of SnO_(2),while the C and TiO_(2)protecting shells strengthen the structural integrity and enhances the electrical conductivity.As a result,the three-layer structured SnO_(2)@C@TiO_(2)hollow spheres demonstrate enhanced Na storage performances.The SnO_(2)@C@TiO_(2)manifests a reversible capacity two times to that of pristine SnO_(2)hollow spheres.In addition,Ex situ XRD reveals highly reversible alloying and conversion reactions in SnO_(2)@C@TiO_(2)hollow spheres.This study suggests the introduction of a hollow cavity and robust protecting shells is a promising strategy for constructing SIB anode materials.
文摘Zirconia hollow sphere products are ultra-high temperature energy saving lightweight insulating refractories in zirconia system.They not only have the same refractoriness as zirconia products,but also have the advantages of low bulk density and excellent thermal insulation properties.Their thermal conductivity is 0.3-0.4 W · m-1 · K-1 only 1/2 of that of the ordinary zirconia products.They are special refractories which can be used steadily up to 2 400 ℃ in oxidation,reduction and vacuum atmospheres.Zirconia hollow sphere products are the best lining refractories for various ultra-high temperature kilns and furnaces of tungsten and molybdenum metal products processing,artificial crystals,and quartz industrial production.
文摘β-SiAION hollow spheres were prepared by carbothermal reduction method, using coal fly ash ( 〈 15 μm, 43 - 77 μm, and 〉 100 μm) and active carbon in Some proportion (20% less than theoretical addition, theoretical addition and 10% excess theoretical addition) as starting materials, putting into alumina crucible in high temperature nitriding furnace after well mixed, and holding at 1 300 ℃, 1 350 ℃, 1 400 ℃, 1 450 ℃, and 1 500 ℃ for 6 h. Effects of temperature, particle size of the microsphere . and addition of active carbon on the phase composition and microstructure of the nitridized products were studied by means of XRD and SEM. The results show that the nitridation reaction starts at 1 300 ℃ ; excess active carbon is necessary to form β-SiAION hollow spheres, and particle size is the important parameter to form the hollow spheres nitridized products β-SiAION; at 1 500 ℃, when the active carbon is 10% in excess, the β-SiAlON hollow spheres, which were prepared using coal fly ash with particle size 〉 100 μm, are featured with rough surface, high hollowness and low density.
基金This work is supported partially by the project of the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(Nos.LAPS21004,LAPS202114)National Natural Science Foundation of China(Nos.52272200,51972110,52102245 and 52072121)+6 种基金Beijing Science and Technology Project(No.Z211100004621010)Beijing Natural Science Foundation(Nos.2222076,2222077)Hebei Natural Science Foundation(No.E2022502022)Huaneng Group Headquarters Science and Technology Project(No.HNKJ20-H88)2022 Strategic Research Key Project of Science and Technology Commission of the Ministry of Education,China Postdoctoral Science Foundation(No.2022M721129)the Fundamental Research Funds for the Central Universities(Nos.2022MS030,2021MS028,2020MS023,2020MS028)the NCEPU“Double First-Class”Program.This research was also supported by Brain Pool program funded by the Ministry of Science and ICT through the National Research Foundation of Korea(No.2021H1D3A2A01100019).
文摘High-performance and low-cost gas sensors are highly desirable and involved in industrial production and environmental detection.The combination of highly conductive MXene and metal oxide materials is a promising strategy to further improve the sensing performances.In this study,the hollow SnO_(2)nanospheres and few-layer MXene are assembled rationally via facile electrostatic synthesis processes,then the SnO_(2)/Ti_(3)C_(2)T_(x)nanocomposites were obtained.Compared with that based on either pure SnO_(2)nanoparticles or hollow nanospheres of SnO_(2),the SnO_(2)/Ti_(3)C_(2)T_(x)composite-based sensor exhibits much better sensing performances such as higher response(36.979),faster response time(5 s),and much improved selectivity as well as stability(15 days)to 100ppm C2H5OH at low working temperature(200°C).The improved sensing performances are mainly attributed to the large specific surface area and significantly increased oxygen vacancy concentration,which provides a large number of active sites for gas adsorption and surface catalytic reaction.In addition,the heterostructure interfaces between SnO_(2)hollow spheres and MXene layers are beneficial to gas sensing behaviors due to the synergistic effect.
基金financial supports from the Instrument & Equipment Open Funding of Nanjing University of Science and TechnologyNational Natural Science Foundation of China (No. 21875108)the Fundamental Research Funds for the Central Universities (No. 30921013106)。
文摘Mesoporous silica hollow spheres with a homogenous and high content distribution of Fe and Co were synthesized by a facile one-pot hydrothermal process. The sub-nanometer bimetallic components inside the silica framework facilitate the stable fixation and the open accessibility to active sites. The co-doped Fe/Co in the spheres showed excellent peroxidase-like activity and much higher catalytic performance than their monometallic-supported spheres. The synergistic effect between Fe and Co promotes the continuous formation of functional radicals during the oxidation process and thus accelerates the reaction rate. When used for colorimetric detection of hydrogen peroxide(H_(2)O_(2)), the Fe/Co incorporated silica hollow spheres show the capability of detection of H_(2)O_(2) in a wide range(10-250 μmol/L) and with the low detection limit of 0.012 ppm.
基金supported by the National Natural Science Foundation of China (21972124, 22272148)the Priority Academic Program Development of Jiangsu Higher Education Institution。
文摘The strong metal-support interaction inducing combined effect plays a crucial role in the catalysis reaction. Herein, we revealed that the combined advantages of MoSe_(2), Ru, and hollow carbon spheres in the form of Ru nanoparticles(NPs) anchored on a two-dimensionally ordered MoSe_(2) nanosheet-embedded mesoporous hollow carbon spheres surface(Ru/MoSe_(2)@MHCS) for the largely boosted hydrogen evolution reaction(HER) performance. The combined advantages from the conductive support, oxyphilic MoSe_(2), and Ru active sites imparted a strong synergistic effect and charge redistribution in the Ru periphery which induced high catalytic activity, stability, and kinetics for HER. Specifically, the obtained Ru/MoSe_(2)@MHCS required a small overpotential of 25.5 and 38.4 mV to drive the kinetic current density of 10 mA cm^(-2)both in acid and alkaline media, respectively, which was comparable to that of the Pt/C catalyst. Experimental and theoretical results demonstrated that the charge transfer from MoSe_(2) to Ru NPs enriched the electronic density of Ru sites and thus facilitated hydrogen adsorption and water dissociation. The current work showed the significant interfacial engineering in Ru-based catalysts development and catalysis promotion effect understanding via the metal-support interaction.
基金supported by the Capacity Building Program of Shanghai Local Universities(12160503600)
文摘CeO_2 hollow spheres were synthesized by polystryrene sphere(PS) templates and CeO_2 nanoparticles were prepared by a facile method. The as-obtained products were characterized by scanning electron microscopy(SEM), N_2 adsorption-desorption, X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR) and UV-vis diffuse reflectance spectra. The results showed that the structure of the obtained CeO_2 hollow spheres was hollow microsphere with a diameter of 380 nm and the average particle size of CeO_2 nanoparticles was about 1700 nm. The two samples' Brunauer-Emmett-Teller(BET) surface area was 67.1 and 37.2 m^2/g. The CeO_2 hollow spheres had a better performance than nanoparticles at UV-shielding because of higher surface area and the structure of hollow sphere.
文摘A strategy of intensifying the visible light harvesting ability of anatase Ti02 hollow spheres(HSs)was developed,in which both sides of Ti02 HSs were utilised for stabilising Au nanoparticles(NPs)through the sacrificial templating method and convex surface-induced confinement.The composite structure of single Au NP yolk-Ti02 shell-Au NPs,denoted as Au@Au(Ti02,was rendered and confirmed by the transmission electron microscopy analysis.Au@Au(Ti02 showed enhanced photocatalytic activity in the degradation of methylene blue and phenol in aqueous phase under visible light surpassing that of other reference materials such as Au(Ti02 by 77%and Au@P25 by 52%,respectively,in phenol degradation.
基金financially supported by the National Natural Science Foundation of China(Nos.51961135303,51932007,21871217,U1905215 and U1705251)the Innovative Research Funds of Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory(No.XHD2020-001)+2 种基金the National Postdoctoral Program for Innovative Talents(No.BX20200261)China Postdoctoral Science Foundation(No.2020M682501)Dean Research Fund(Nos.04530 and 04554)。
文摘Recently, researchers have focused on designing and fabricating highly efficient catalysts for photocatalytic organic pollutant removal. Herein, CeO_(2) hollow spheres were prepared through a simple template method followed by calcination at different temperatures for the tetracycline(TC) degradation under simulated solar light illumination. With a calcination temperature ranging from400 to 800 ℃, the as-prepared CeO_(2) hollow structure annealed at 600 ℃(C_(600)) exhibited the best degradation performance with a degradation rate constant of0.066 min-1, which was about six and five times higher than those of the uncalcined sample(C_(0)) and the sample calcined at 800 ℃(C_(800)), respectively. Moreover, sample C_(600)was also superior to the CeO_(2) solid particle photocatalyst. The characterisation results showed that the improved photocatalytic performance was mainly ascribed to the synergistic effect of large specific surface areas, high crystallisation and excellent light scattering ability. Furthermore, the results of active species trapping experiments demonstrated that the superoxide anion(·O_(2)^(-)) radical and hole(h^(+)) played dominant roles in TC degradation. Subsequently, the possible TC degradation pathways and photocatalytic mechanism of CeO_(2) hollow spheres were proposed on the basis of high-performance liquid chromatography–mass spectrometry analysis, main active species and band edge positions of CeO_(2). The results of this study provide a basis for designing and exploring hollow structure catalysts for energy conversion and environmental remediation.
基金financially supported by the Natural Science Foundation of China (Grant No.21473093)Fundamental Research Funds for the Central Universities and Tianjin Research Program of Application Foundation and Advanced Technology (Grant No.14JCYBJC41300)Ph.D. Candidate Research Innovation Fund of Nankai University
文摘MoS_2 has attracted attention as a promising hydrogen evolution reaction(HER) catalyst and a supercapacitor electrode material. However, its catalytic activity and capacitive performance are still hindered by its aggregation and poor intrinsic conductivity. Here, hollow rGO sphere-supported ultrathin MoS_2 nanosheet arrays(hrGO@MoS_2) are constructed via a dual-template approach and employed as bifunctional HER catalyst and supercapacitor electrode material. Because of the expanded interlayer spacing in MoS_2 nanosheets and more exposed electroactive S–Mo–S edges, the constructed h-rGO@MoS_2 architectures exhibit enhanced HER performance. Furthermore, benefiting from the synergistic effect of the improved conductivity and boosted specific surface areas(144.9 m^2 g^(-1), ca. 4.6-times that of pristine MoS_2), the h-rGO@MoS_2 architecture shows a high specific capacitance(238 F g^(-1) at a current density of 0.5 A g^(-1)), excellent rate capacitance, and remarkable cycle stability. Our synthesis method may be extended to construct other vertically aligned hollow architectures,which may serve both as efficient HER catalysts and supercapacitor electrodes.