This paper reports that Cr2O3 hollow nanospheres (HNs) were synthesized via a hydrothermal approach and characterized by scanning electron microscopy, x-ray powder diffraction, transmission electron microscopy (TEM...This paper reports that Cr2O3 hollow nanospheres (HNs) were synthesized via a hydrothermal approach and characterized by scanning electron microscopy, x-ray powder diffraction, transmission electron microscopy (TEM), selective area electron diffraction and high resolution TEM, respectively. In addition, the room-temperature (RT) gas sensing properties of Cr2O3 HNs and conventional powders (CPs) were investigated by means of the surface photovoltage technique. The experimental data demonstrate that the RT gas sensor of the as-fabricated HNs reaches below 5 ppm whereas that of the CPs is about 40 ppm, which results from there being much more adsorbed and desorbed oxygen in HNs than in CPs at RT. The as-prepared Cr2O3 HNs could have potential applications as RT nanosensors.展开更多
A novel method to prepare crosslinked polyethyleneimine (CPEI) hollow nanospheres was reported. Uniform silica nanospheres were used as templates, 3-aminopropyl trimethoxysilane (APS) was immobilized on the surfac...A novel method to prepare crosslinked polyethyleneimine (CPEI) hollow nanospheres was reported. Uniform silica nanospheres were used as templates, 3-aminopropyl trimethoxysilane (APS) was immobilized on the surface of silica nanospheres as couple agent. Aziridine was initiated ring-opening polymerization with the amino groups in APS to form polyethyleneimine (PEI) shell layer. 1,4-Butanediol diacrylate was utilized to crosslink PEI polymeric shell. The silica nanospheres in core were etched by hydrofluoric acid to obtain hollow CPEI nanospheres. The hollow nanospheres were characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA).展开更多
The PdCo bimetallic hollow nanospheres with 80 nm average diameter and around 9.0 nm thickness of the shell were prepared with a special reduction method and characterized with transmission electron microscopy (TEM)...The PdCo bimetallic hollow nanospheres with 80 nm average diameter and around 9.0 nm thickness of the shell were prepared with a special reduction method and characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). The electrochemical measurements illustrated that the electrocatalytic activity of the PdCo bimetallic hollow nanospheres for the oxidation of formic acid is much higher than that of the Pd solid nanospheres.展开更多
We report a facile template-free fabrication of heterostructured Co_(3)O_(4)/CuO hollow nanospheres using pre-synthesized Co/Cu-glycerate as conformal precursor.The introduction of copper nitrate in the solvothermal r...We report a facile template-free fabrication of heterostructured Co_(3)O_(4)/CuO hollow nanospheres using pre-synthesized Co/Cu-glycerate as conformal precursor.The introduction of copper nitrate in the solvothermal reaction system of glycerol/isopropanol/cobalt nitrate readily induces the conversion from solid Co-glycerate to hollow Co/Cu-glycerate nanospheres,and the effect of the Co/Cu atomic ratio on the structure evolution of the metal glycerates as well as their corresponding oxides were investigated.When examined as anode materials for lithium-ion batteries,the well-defined Co_(3)O_(4)/CuO hollow nanospheres with Co/Cu molar ratio of 2.0 demonstrate excellent lithium storage performance,delivering a high reversible capacity of 930 mAh/g after 300 cycles at a current density of 0.5 A/g and a stable capacity of 650 mAh/g after 500 cycles even at a higher current density of 2.0 A/g,which are much better than their counterparts of bare CuO and Co_(3)O_(4).The enhanced lithium storage performance can be attributed to the synergistic effect of the CuO and Co_(3)O_(4)heterostructure with hollow spherical morphology,which greatly enhances the charge/electrolyte transfer and effectively buffers the volume changes upon lithiation/delithiation cycling.展开更多
Hollow nanostructures with structural advantages have been widely exploited as catalysts in electrochemical reactions.However,there are only limited strategies for constructing hollow Pd-based nanostructures.In this w...Hollow nanostructures with structural advantages have been widely exploited as catalysts in electrochemical reactions.However,there are only limited strategies for constructing hollow Pd-based nanostructures.In this work,Pd4S hollow nanospheres(Pd4S HNSs)are synthesized with a facile wet-chemical method via a self-templating process.Intermediate Pd-L-cysteine solid nanospheres(SNSs)were firstly obtained by the coordination of L-cysteine with Pd^(2+),and then in situ converted to hollow nanospheres in the following reduction process.The formation mechanism of the Pd4S HNSs was studied,and the size of the Pd4S HNSs can be readily adjusted by tuning the size of the SNSs.The hollow morphology would help the exposure of active sites and the prevention of aggregation during the catalytic reactions.As a result,the Pd4S HNSs exhibit improved catalytic performances in the oxygen reduction reactions,with a half-wave potential of 0.913 V vs.reversible hydrogen electrode(RHE)and impressive stability in the accelerated durability test.展开更多
Covalent organic frameworks(COFs), as highly tunable porous crystalline materials, have promising applications in potassium-ion batteries(PIBs) due to their abundant charge carrier transport channels and excellent str...Covalent organic frameworks(COFs), as highly tunable porous crystalline materials, have promising applications in potassium-ion batteries(PIBs) due to their abundant charge carrier transport channels and excellent structural stability. However, the excessive stacking of interlayer electron clouds makes it difficult to expose internal active sites. Strategies to design functional COFs with controllable morphology and copious active sites are promising but still challenging. Herein, by utilizing the condensation between1,3,5-triformylbenzene(TFB) and p-phenylenediamine(PPD) and using amino-modified SiO_(2) nanospheres as templates, we synthesize core-shell NH_(2)-SiO_(2)@TP-COF. Through NaOH etching of NH_(2)-SiO_(2)@TP-COF, we obtain imine-based TP-COF hollow nanospheres, which shows excellent potassium storage performance when applied to the anode for PIBs. Ex-situ analysis and density functional theory calculations reveal that C=N groups and benzenes are active sites for K^(+) storage.展开更多
Herein,an intense electrochemiluminescence(ECL)was achieved based on Pt hollow nanospheres/rubrene nanoleaves(Pt HNSs/Rub NLs)without the addition of any coreactant,which was employed for ultrasensitive detection of c...Herein,an intense electrochemiluminescence(ECL)was achieved based on Pt hollow nanospheres/rubrene nanoleaves(Pt HNSs/Rub NLs)without the addition of any coreactant,which was employed for ultrasensitive detection of carcinoembryonic antigen(CEA)coupled with an M-shaped DNA walker(M-DNA walker)as signal switch.Specifically,in comparison with platinum nanoparticles(Pt NPs),Pt HNSs revealed excellent catalytic performance and pore confinement-enhanced ECL,which could significantly amplify ECL intensity of Rub NLs/dissolved O_(2)(DO)binary system.Then,the tracks and M-DNA walker were confined on the Pt HNSs simultaneously to promote the reaction efficiency,whose M-structure boosted the interaction sites between walking strands and tracks and reduced the rigidity of their recognition.Once the CEA approached the sensing interface,the M-DNA walker was activated based on highly specific aptamer recognition to recover ECL intensity with the assistance of exonucleaseⅢ(ExoⅢ).As proof of concept,the“on-off-on”switch aptasensor was constructed for CEA detection with a low detection limit of 0.20 fg/m L.The principle of the constructed ECL aptasensor also enables a universal platform for sensitive detection of other tumor markers.展开更多
Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in seconda...Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in secondary batteries.In this work,hollow carbon(HC) nanospheres embedded with S,P co-doped NiSe_(2)nanoparticles are fabricated by "drop and dry" and "dissolving and precipitation" processes to form Ni(OH)2nanocrystals followed by annealing with S and P dopants to form nanoparticles.The resultant S,P-NiSe_(2)/HC composite exhibits excellent cyclic performance with 131.6 mA h g^(-1)at1000 mA g^(-1)after 3000 cycles for K^(+)storage and a capacity of 417.1 mA h g^(-1)at 1000 mA g^(-1)after1000 cycles for Li^(+)storage.K-ion full cells are assembled and deliver superior cycling stability with a ca pacity of 72.5 mA h g^(-1)at 200 mA g^(-1)after 500 cycles.The hollow carbon shell with excellent electrical conductivity effectively promotes the transporta tion and tolerates large volume variation for both K^(+)and Li^(+).Density functional theory calculations confirm that the S and P co-doping NiSe_(2) enables stronger adsorption of K^(+)ions and higher electrical conductivity that contributes to the improved electrochemical performance.展开更多
Ion conductive membranes(ICMs)with highly conductive proton selectivity are of significant importance and greatly desired for energy storage devices.However,it is extremely challenging to construct fast proton-selecti...Ion conductive membranes(ICMs)with highly conductive proton selectivity are of significant importance and greatly desired for energy storage devices.However,it is extremely challenging to construct fast proton-selective transport channels in ICMs.Herein,a membrane with highly conductive proton selectivity was fabricated by incorporating porous carbon sieving nanospheres with a hollow structure(HCSNs)in a polymer matrix.Due to the precise ion sieving ability of the microporous carbon shells and the fast proton transport through their accessible internal cavities,this advanced membrane presented a proton conductivity(0.084 S·cm^(-1))superior to those of a commercial Nation 212(N212)membrane(0.033S·cm^(-1))and a pure polymer membrane(0.049 S·cm^(-1)).The corresponding proton selectivity of the membrane(6.68×10^(5) S·min·cm^(-3))was found to be enhanced by about 5.9-fold and 4.3-fold,respectively,compared with those of the N212 membrane(1.13×10^(5) S·min·cm^(-3))and the pure membrane(1.56×10^(5) S·min·cm^(-3)).Low-field nuclear magnetic resonance(LF-NMR)clearly revealed the fast protonselective transport channels enabled by the HCSNs in the polymeric membrane.The proposed membrane exhibited an outstanding energy efficiency(EE)of 84%and long-term stability over 1400 cycles with a0.065%capacity decay per cycle at 120 mA·cm^(-2) in a typical vanadium flow battery(VFB)system.展开更多
Achieving high-efficiency sodium storage in metal selenides is still severely constrained in consideration of their inferior electronic conductivity and inadequate Na^(+)insertion pathways and active sites.Heteroatom ...Achieving high-efficiency sodium storage in metal selenides is still severely constrained in consideration of their inferior electronic conductivity and inadequate Na^(+)insertion pathways and active sites.Heteroatom doping accompanied by spontaneously developed lattice defects can effectively tune electronic structure of metal selenides,which give a strong effect to motivate fast charge transfer and Na^(+)accessibility.Herein,we finely designed and successfully constructed a fascinating phosphorus-doped Cu_(2)Se@C hollow nanosphere with abundant vacancy defects(Cu_(2)P_(x)Se_(1-x)@C)through a combination strategy of selenization of Cu_(2)O nanosphere template,self-polymerization of dopamine,and subsequent phosphorization treatment.Such exquisite composite possesses enriched active sites,superior conductivity,and sufficient Na^(+)insertion channel,which enable much faster Na^(+)diffusion rates and more remarkable pseudocapacitive features,Satisfyingly,the Cu_(2)P_(x)Se_(1-x)@C composites manifest the supernormal sodium-storage capabilities,that is,a reversible capacity of 403.7 mA h g^(-1) at 1.0 A g^(-1) over 100 cycles,and an ultrastable cyclic lifespan over 1000 cycles at 20.0 A g^(-1) with a high capacity-retention of about249.7 mA h g^(-1).The phase transformation of the Cu_(2)P_(x)Se_(1-x)@C involving the intercalation of Na^(+)into Cu_(2)Se and the following conversion of NaCuSe to Cu and Na2Se were further demonstrated through a series of ex-situ characterization methods.DFT results demonstrate that the coexistence of phosphorusdoping and vacancy defects within Cu_(2)Se results in the reduction of Na^(+)adsorption energy from-1.47to-1.56 eV improving the conductivity of Cu_(2)Se to further accelerate fast Na^(+)mobility.展开更多
Recently, Prussian blue and its analogues (PBAs) have attracted tremendous attention as cathode materials for sodium-ion batteries because of their good cycling performance, low cost, and environmental friendliness....Recently, Prussian blue and its analogues (PBAs) have attracted tremendous attention as cathode materials for sodium-ion batteries because of their good cycling performance, low cost, and environmental friendliness. However, they still suffer from kinetic problems associated with the solid-state diffusion of sodium ions during charge and discharge processes, which leads to low specific capacity and poor rate performances. In this work, novel sodium iron hexacyanoferrate nanospheres with a hierarchical hollow architecture have been fabricated as cathode material for sodium-ion batteries by a facile template method. Due to the unique hollow sphere morpholog~ sodium iron hexacyanoferrate nanospheres can provide large numbers of active sites and high diffusion dynamics for sodium ions, thus delivering a high specific capacity (142 mAh/g), a superior rate capabili, and an excellent cycling stability. Furthermore, the sodium insertion/extraction mechanism has been studied by in situ X-ray diffraction, which provides further insight into the crystal structure change of the sodium iron hexacyanoferrate nanosphere cathode material during charge and discharge processes.展开更多
SnO2 hollow nanospheres were successfully synthesized via a facile one-step solvothermal method.Characterizations show that the as-prepared SnO2 spheres are of hollow structure with a diameter at around 50 nm,and espe...SnO2 hollow nanospheres were successfully synthesized via a facile one-step solvothermal method.Characterizations show that the as-prepared SnO2 spheres are of hollow structure with a diameter at around 50 nm,and especially,the shell of the spheres is assembled by single layer SnO2 nanocrystals.The surface area of the material reaches up to 202.5 m^2/g.As an anode material for Li ion batteries,the sample exhibited improved electrochemical performance compared with commercial SnO2 particles.After cycled at high current rate of 0.5 C,1 C and 0.5 C for 20 cycles,respectively,the electrode can maintain a capacity of 509 mAh/g.The suitable shell thickness/diameter ratio endows the good structural stability of the material during cycling,which promises the excellent cycling performance of the electrode.The large surface area and the ultra thin shell ensure the high rate performance of the material.展开更多
Although lithium-sulfur batteries are one of promising rechargeable energy storage devices,their wide applications are impeded by the lithium polysulfides shutle effect,low electronic conductivity of the cathode,and s...Although lithium-sulfur batteries are one of promising rechargeable energy storage devices,their wide applications are impeded by the lithium polysulfides shutle effect,low electronic conductivity of the cathode,and sluggish redox reaction kinetics of lithium polysulfides.In this work,reduced graphene oxide was decorated with CoSe2 hollow nanospheres to form an RGO-CoSe2 composite that was used as a host material to support S in the cathode.The RGO-CoSe2 composite has the following superiorities:(1)enhanced electronic conductity,(2)accommodation of the volumetric change of cathode materials,(3)effective confinement of numerous lithium polysulfides species due to chemisorption,(4)expedition of the redox kinetics of lithium polysulfides.As expected,the RGO-CoSez-based cathode exhibited the reversible specific capacity of 1,044.7 mAh/g at 0.2C and 695.7 mAh/g at 2C,together with ecellent cycling stability of 0.071% average capacity decay per cycle over 400 cycles at 1C.展开更多
Size tunable cobalt hollow nanospheres with high catalytic activity for the ammonia borane(AB) hydrolysis have been synthesized by using the solvothermal method. The complexation between Co2+and ethylenediamine is obs...Size tunable cobalt hollow nanospheres with high catalytic activity for the ammonia borane(AB) hydrolysis have been synthesized by using the solvothermal method. The complexation between Co2+and ethylenediamine is observed to be critical for the formation of the cobalt hollow nanospherical structure.The morphology of the cobalt hollow nanospheres can be regulated by adjusting the original ethylenediamine/ethanol volume ratio, reaction time and temperature. Impressively, the magnetic property study reveals that the coercivity of the as-synthesized cobalt hollow nanospheres is much enhanced compared with that of bulk cobalt materials. Meanwhile, Co/Pt bimetal hollow nanospheres(Co Pt HS) and graphene-cobalt hollow composite nanospheres(Co HS-r GO) have also been explored. In comparison with the cobalt hollow nanospheres, both the Co Pt HS and Co HS-r GO show higher catalytic activities and better repeatability for the catalytic hydrogen generation from AB hydrolysis. Moreover, it is noted that these catalysts could be recycled by using the magnetic separation method.展开更多
Hollow micro-/nanostructures have achieved great success in the field of renewable battery materials by reducing the volume change and promoting the ion transport.Double-shelled Co_(3)V_(2)O__(8)hollow nanospheres(CVO...Hollow micro-/nanostructures have achieved great success in the field of renewable battery materials by reducing the volume change and promoting the ion transport.Double-shelled Co_(3)V_(2)O__(8)hollow nanospheres(CVODSS)were synthesized using a facile solvothermal method followed by a thermal treatment in the absence of any surfactant.Meanwhile,two other architectures of hollow nanospheres and nanoparticles were obtained by changing the annealing temperature.Benefiting from the desired hollow structure,the CVO-DSS electrode exhibits excellent lithium storage properties as an anode.It exhibits a reversible discharge capacity of 1210 m Ah·g^(-1)at200 m A·g^(-1)after 100 cycles and a satisfactorily high rate capacity of 628 m Ah·g^(-1)after 800 cycles at 5000 m A·g^(-1).These hollow nanostructures can efficiently enhance the contact area of the electrolyte/electrode interface,promote the diffusion of lithium ions and electrons and slow down the capacity loss during long cycles.展开更多
The widespread commercial application of direct formate fuel cell(DFFC)is limited by the lack of efficient electrocatalysts for the formate oxidation reaction(FOR).AgPdCo hollow nanospheres(H-NSs)with jagged surfaces ...The widespread commercial application of direct formate fuel cell(DFFC)is limited by the lack of efficient electrocatalysts for the formate oxidation reaction(FOR).AgPdCo hollow nanospheres(H-NSs)with jagged surfaces are successfully synthesized via a facile method involving the wet-chemical synthesis of AgPdCo nanospheres(NSs)and galvanic replacement reaction between Pd salt and AgPdCo NSs.Surpassing Ag_(30)Pd_(69)Co_(1) NSs and most of previously reported electrocatalysts,Ag_(9)Pd_(90)Co_(1) H-NSs exhibit extremely high FOR activity with a peak current density of 3.08 A·mg_(Pd)^(−1).Apart from the competitive activity,Ag_(9)Pd_(90)Co_(1) H-NSs show greatly improved chronoamperometric and cycling stability,whereby the current density retains about 0.24 A·mg_(Pd)^(−1) after 3,600 s electrocatalysis and the mass activity maintains 54.06%of the initial value after 500 cycles.The unique hollow nanosphere and synergistic effect are responsible for the enhanced activity and stability.This study will provide new clues for the development of outstanding electrocatalysts.展开更多
As a newly discovered member of the ttmgstate famil3~ InWO4 hollow nanospheres with a monoclinic wolframite structure were synthesized successfully. The crystal phase of InWO4 was investigated via a combination of CAS...As a newly discovered member of the ttmgstate famil3~ InWO4 hollow nanospheres with a monoclinic wolframite structure were synthesized successfully. The crystal phase of InWO4 was investigated via a combination of CASTEP geometric optimization and experimental simulation. InWO, has a space group of P2/c with two InWO, formula units per unit cell. The optimized cell dimensions are a = 5.16 A, b = 5.97 A, and c = 5.23 A, with a = 90°, β= 92.11°, 7 = 90°, giving a unit cell volume of 161.10 A^3, which is consistent with the experimental measurements. More importantly, InWO4 was a promising host material for different Ln^3+ (Ln = Eu and Yb/Er) ions. For InWO4:Yb^3+/Er^3+ excited at 980 nm, transitions from the ^4G11/2 (384 nm), ^2H9/2 (411 nm), and ^4F7/2 (487 nm) levels to the ground state (^4I15/2) of Er^3+ were observed. In addition to the aforementioned properties, the InWO4 hollow nanospheres can be used to improve the performance of dye-sensitized solar cells, which is chiefly attributed to their light scattering.展开更多
The large overpotential for conventional Li-O_(2) batteries is an enormous challenge,which impedes their practical application.Here,we prepare a defective TiO_(2)(Ov-TiO_(2)) hollow nanosphere as photoelectrocatalyst ...The large overpotential for conventional Li-O_(2) batteries is an enormous challenge,which impedes their practical application.Here,we prepare a defective TiO_(2)(Ov-TiO_(2)) hollow nanosphere as photoelectrocatalyst for photo-assisted Li-O_(2) batteries to reduce the overpotential.Under illumination,the oxygen vacancies as a charge separation center contribute to the separation of electrons and holes.The generated electrons could promote reducing O_(2) to Li_(2)O_(2) during oxygen reduction reaction(ORR)process,while the generated holes are beneficial to Li_(2)O_(2) decomposition during oxygen evolution reaction(OER)process.Additionally,the proper concentration of oxygen vacancies will decrease the recombination rate between electrons and holes.The photo-assisted Li-O_(2) batteries with Ov-TiO_(2)-650 exhibit advanced performances,such as the low overpotential(0.70 V),the fine rate capability,and the considerable reversibility accompanied with the formation/decomposition of Li_(2)O_(2).We expect that these results could open a new mind to design of highly efficient photo-electrocatalysts for photo-assisted Li-O_(2) battery.展开更多
The construction of built-in electric field is generally considered as an effective strategy to enhance photocatalytic performance due to its significant role in charge separation.Herein,a built-in electric field with...The construction of built-in electric field is generally considered as an effective strategy to enhance photocatalytic performance due to its significant role in charge separation.Herein,a built-in electric field within g-C_(3)N_4 hollow nanospheres co-doped with sulfur and oxygen and modified in-situ Ni_(2)P is proposed.Ni_(2)P/SO-HC_(3)N_4 exhibits significantly enhanced board spectrum photocatalytic properties for hydrogen precipitation(5.21 mmol h^(-1)g^(-1))and photocatalytic Cr(VI)reduction without the use of noble metal.It also achieves high photocatalytic sterilization activity and remarkable stability when used to completely inactivate E.coli(10~7)in 60 min under Vis-NIR light irradiation.The enhanced performance is attributed to the formation of a curved hollow sphere structure,which promotes the electron transfer between the inner and outer layers.In addition,co-doping inhibits the recombination of photogenerated carriers,and the built-in electric field recombined with Ni_(2)facilitates the electron transfer between the composite interfaces.This design strategy demonstrates an original method of devising multifunctional photocatalysts with enhanced activity and stability.展开更多
The TiO2 hollow nanospheres with diameters of about 230 nm were prepared by a simple and controllable route based on hydrolysis of Ti(OBu)4 on the surfaces of the Cu20 solid nanospheres followed by inward etching of...The TiO2 hollow nanospheres with diameters of about 230 nm were prepared by a simple and controllable route based on hydrolysis of Ti(OBu)4 on the surfaces of the Cu20 solid nanospheres followed by inward etching of the Cu20 nanospheres. The as-prepared samples were characterized by X-ray diffraction, transmis- sion electron microscopy and scanning electron micro- scopy. The further post-heat treatment led to the high crystallization of the TiO2 hollow nanospheres. The photocatalytic performances of these samples were evaluated for the photodegradation of rhodamine B (RhB) under UV-light irradiation. The as-prepared TiO2 hollow nanospheres showed higher photocatalytic activity than the CuO and the CuO/TiO2 hollow nanospheres. Effects of temperature and time for post-heat treatment of TiO2 as well as initial RhB concentrations on the RhB photodegradation have also been studied. The results show that the TiO2 hollow nanospheres have the good reusability as photocatalysts and are promising in waste water treatment.展开更多
基金sponsored by the Program for Science & Technology Innovation Talents in Universities of Henan Province (Grant No 2008 HASTIT002)the Innovation Scientists and Technicians Troop Construction Projects of Henan Province of Chinathe National Natural Science Foundation of China (Grant No 20941002)
文摘This paper reports that Cr2O3 hollow nanospheres (HNs) were synthesized via a hydrothermal approach and characterized by scanning electron microscopy, x-ray powder diffraction, transmission electron microscopy (TEM), selective area electron diffraction and high resolution TEM, respectively. In addition, the room-temperature (RT) gas sensing properties of Cr2O3 HNs and conventional powders (CPs) were investigated by means of the surface photovoltage technique. The experimental data demonstrate that the RT gas sensor of the as-fabricated HNs reaches below 5 ppm whereas that of the CPs is about 40 ppm, which results from there being much more adsorbed and desorbed oxygen in HNs than in CPs at RT. The as-prepared Cr2O3 HNs could have potential applications as RT nanosensors.
基金This work was financially supported by the National Basic Research Program of China(National 973 program,No.2005 CB623903).
文摘A novel method to prepare crosslinked polyethyleneimine (CPEI) hollow nanospheres was reported. Uniform silica nanospheres were used as templates, 3-aminopropyl trimethoxysilane (APS) was immobilized on the surface of silica nanospheres as couple agent. Aziridine was initiated ring-opening polymerization with the amino groups in APS to form polyethyleneimine (PEI) shell layer. 1,4-Butanediol diacrylate was utilized to crosslink PEI polymeric shell. The silica nanospheres in core were etched by hydrofluoric acid to obtain hollow CPEI nanospheres. The hollow nanospheres were characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA).
基金the National Natural Science Foundation of China(Nos.20473038,20573057)the Natural Science Foundation of Jiangsu Province(No.BK2005139,BG2003022,BK2006224)the Natural Science Foundation of the Education Committee of Jiangsu Province(No.05KJB 150061,04KJA 150066).
文摘The PdCo bimetallic hollow nanospheres with 80 nm average diameter and around 9.0 nm thickness of the shell were prepared with a special reduction method and characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). The electrochemical measurements illustrated that the electrocatalytic activity of the PdCo bimetallic hollow nanospheres for the oxidation of formic acid is much higher than that of the Pd solid nanospheres.
基金supported by the National Natural Science Foundation of China(No.52077175).
文摘We report a facile template-free fabrication of heterostructured Co_(3)O_(4)/CuO hollow nanospheres using pre-synthesized Co/Cu-glycerate as conformal precursor.The introduction of copper nitrate in the solvothermal reaction system of glycerol/isopropanol/cobalt nitrate readily induces the conversion from solid Co-glycerate to hollow Co/Cu-glycerate nanospheres,and the effect of the Co/Cu atomic ratio on the structure evolution of the metal glycerates as well as their corresponding oxides were investigated.When examined as anode materials for lithium-ion batteries,the well-defined Co_(3)O_(4)/CuO hollow nanospheres with Co/Cu molar ratio of 2.0 demonstrate excellent lithium storage performance,delivering a high reversible capacity of 930 mAh/g after 300 cycles at a current density of 0.5 A/g and a stable capacity of 650 mAh/g after 500 cycles even at a higher current density of 2.0 A/g,which are much better than their counterparts of bare CuO and Co_(3)O_(4).The enhanced lithium storage performance can be attributed to the synergistic effect of the CuO and Co_(3)O_(4)heterostructure with hollow spherical morphology,which greatly enhances the charge/electrolyte transfer and effectively buffers the volume changes upon lithiation/delithiation cycling.
基金the National Natural Science Foundation of China(Nos.21703104,21673117,and 91956109)Nanjing Tech University(No.39837131).
文摘Hollow nanostructures with structural advantages have been widely exploited as catalysts in electrochemical reactions.However,there are only limited strategies for constructing hollow Pd-based nanostructures.In this work,Pd4S hollow nanospheres(Pd4S HNSs)are synthesized with a facile wet-chemical method via a self-templating process.Intermediate Pd-L-cysteine solid nanospheres(SNSs)were firstly obtained by the coordination of L-cysteine with Pd^(2+),and then in situ converted to hollow nanospheres in the following reduction process.The formation mechanism of the Pd4S HNSs was studied,and the size of the Pd4S HNSs can be readily adjusted by tuning the size of the SNSs.The hollow morphology would help the exposure of active sites and the prevention of aggregation during the catalytic reactions.As a result,the Pd4S HNSs exhibit improved catalytic performances in the oxygen reduction reactions,with a half-wave potential of 0.913 V vs.reversible hydrogen electrode(RHE)and impressive stability in the accelerated durability test.
基金supported by the National Natural Science Foundation of China (No. 22179063)。
文摘Covalent organic frameworks(COFs), as highly tunable porous crystalline materials, have promising applications in potassium-ion batteries(PIBs) due to their abundant charge carrier transport channels and excellent structural stability. However, the excessive stacking of interlayer electron clouds makes it difficult to expose internal active sites. Strategies to design functional COFs with controllable morphology and copious active sites are promising but still challenging. Herein, by utilizing the condensation between1,3,5-triformylbenzene(TFB) and p-phenylenediamine(PPD) and using amino-modified SiO_(2) nanospheres as templates, we synthesize core-shell NH_(2)-SiO_(2)@TP-COF. Through NaOH etching of NH_(2)-SiO_(2)@TP-COF, we obtain imine-based TP-COF hollow nanospheres, which shows excellent potassium storage performance when applied to the anode for PIBs. Ex-situ analysis and density functional theory calculations reveal that C=N groups and benzenes are active sites for K^(+) storage.
基金financially supported by the National Natural Science Foundation(NNSF)of China(No.22022408)the Chongqing Talents Personnel Support Program(No.NCQYC201905067)the Fundamental Research Funds for the Central Universities(No.XDJK2019TJ002)。
文摘Herein,an intense electrochemiluminescence(ECL)was achieved based on Pt hollow nanospheres/rubrene nanoleaves(Pt HNSs/Rub NLs)without the addition of any coreactant,which was employed for ultrasensitive detection of carcinoembryonic antigen(CEA)coupled with an M-shaped DNA walker(M-DNA walker)as signal switch.Specifically,in comparison with platinum nanoparticles(Pt NPs),Pt HNSs revealed excellent catalytic performance and pore confinement-enhanced ECL,which could significantly amplify ECL intensity of Rub NLs/dissolved O_(2)(DO)binary system.Then,the tracks and M-DNA walker were confined on the Pt HNSs simultaneously to promote the reaction efficiency,whose M-structure boosted the interaction sites between walking strands and tracks and reduced the rigidity of their recognition.Once the CEA approached the sensing interface,the M-DNA walker was activated based on highly specific aptamer recognition to recover ECL intensity with the assistance of exonucleaseⅢ(ExoⅢ).As proof of concept,the“on-off-on”switch aptasensor was constructed for CEA detection with a low detection limit of 0.20 fg/m L.The principle of the constructed ECL aptasensor also enables a universal platform for sensitive detection of other tumor markers.
基金financially supported by the Shenzhen Science and Technology Program(JCYJ20220530141012028),ChinaThe National Natural Science Foundation of China(22005178),China+2 种基金The Key Research and Development Program of Shandong Province(2021ZLGX01),ChianThe fellowship of China Postdoctoral Science Foundation(2022M722333),Chianthe Jiangsu Funding Program for Excellent Postdoctoral Talent,Chian。
文摘Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in secondary batteries.In this work,hollow carbon(HC) nanospheres embedded with S,P co-doped NiSe_(2)nanoparticles are fabricated by "drop and dry" and "dissolving and precipitation" processes to form Ni(OH)2nanocrystals followed by annealing with S and P dopants to form nanoparticles.The resultant S,P-NiSe_(2)/HC composite exhibits excellent cyclic performance with 131.6 mA h g^(-1)at1000 mA g^(-1)after 3000 cycles for K^(+)storage and a capacity of 417.1 mA h g^(-1)at 1000 mA g^(-1)after1000 cycles for Li^(+)storage.K-ion full cells are assembled and deliver superior cycling stability with a ca pacity of 72.5 mA h g^(-1)at 200 mA g^(-1)after 500 cycles.The hollow carbon shell with excellent electrical conductivity effectively promotes the transporta tion and tolerates large volume variation for both K^(+)and Li^(+).Density functional theory calculations confirm that the S and P co-doping NiSe_(2) enables stronger adsorption of K^(+)ions and higher electrical conductivity that contributes to the improved electrochemical performance.
基金the support from the National Key Research and Development Program of China(2021YFB3801301)the National Natural Science Foundation of China(22075076,21908098,and 21908054)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Ion conductive membranes(ICMs)with highly conductive proton selectivity are of significant importance and greatly desired for energy storage devices.However,it is extremely challenging to construct fast proton-selective transport channels in ICMs.Herein,a membrane with highly conductive proton selectivity was fabricated by incorporating porous carbon sieving nanospheres with a hollow structure(HCSNs)in a polymer matrix.Due to the precise ion sieving ability of the microporous carbon shells and the fast proton transport through their accessible internal cavities,this advanced membrane presented a proton conductivity(0.084 S·cm^(-1))superior to those of a commercial Nation 212(N212)membrane(0.033S·cm^(-1))and a pure polymer membrane(0.049 S·cm^(-1)).The corresponding proton selectivity of the membrane(6.68×10^(5) S·min·cm^(-3))was found to be enhanced by about 5.9-fold and 4.3-fold,respectively,compared with those of the N212 membrane(1.13×10^(5) S·min·cm^(-3))and the pure membrane(1.56×10^(5) S·min·cm^(-3)).Low-field nuclear magnetic resonance(LF-NMR)clearly revealed the fast protonselective transport channels enabled by the HCSNs in the polymeric membrane.The proposed membrane exhibited an outstanding energy efficiency(EE)of 84%and long-term stability over 1400 cycles with a0.065%capacity decay per cycle at 120 mA·cm^(-2) in a typical vanadium flow battery(VFB)system.
基金supported by the China Postdoctoral Science Foundation(Nos.2021M690534 and 2020M673650)the Science and Technology Research Program of Chongqing Municipal Education Commission(Nos.KJQN202101439 and KJQN202101441)+1 种基金the Innovation Research Team at Institutions of Higher Education in Chongqing(No.CXQT20027)the Program for Vanadium and Titanium Resource Comprehensive Utilization Key Laboratory of Sichuan Province(No.2022FTSZ02)。
文摘Achieving high-efficiency sodium storage in metal selenides is still severely constrained in consideration of their inferior electronic conductivity and inadequate Na^(+)insertion pathways and active sites.Heteroatom doping accompanied by spontaneously developed lattice defects can effectively tune electronic structure of metal selenides,which give a strong effect to motivate fast charge transfer and Na^(+)accessibility.Herein,we finely designed and successfully constructed a fascinating phosphorus-doped Cu_(2)Se@C hollow nanosphere with abundant vacancy defects(Cu_(2)P_(x)Se_(1-x)@C)through a combination strategy of selenization of Cu_(2)O nanosphere template,self-polymerization of dopamine,and subsequent phosphorization treatment.Such exquisite composite possesses enriched active sites,superior conductivity,and sufficient Na^(+)insertion channel,which enable much faster Na^(+)diffusion rates and more remarkable pseudocapacitive features,Satisfyingly,the Cu_(2)P_(x)Se_(1-x)@C composites manifest the supernormal sodium-storage capabilities,that is,a reversible capacity of 403.7 mA h g^(-1) at 1.0 A g^(-1) over 100 cycles,and an ultrastable cyclic lifespan over 1000 cycles at 20.0 A g^(-1) with a high capacity-retention of about249.7 mA h g^(-1).The phase transformation of the Cu_(2)P_(x)Se_(1-x)@C involving the intercalation of Na^(+)into Cu_(2)Se and the following conversion of NaCuSe to Cu and Na2Se were further demonstrated through a series of ex-situ characterization methods.DFT results demonstrate that the coexistence of phosphorusdoping and vacancy defects within Cu_(2)Se results in the reduction of Na^(+)adsorption energy from-1.47to-1.56 eV improving the conductivity of Cu_(2)Se to further accelerate fast Na^(+)mobility.
文摘Recently, Prussian blue and its analogues (PBAs) have attracted tremendous attention as cathode materials for sodium-ion batteries because of their good cycling performance, low cost, and environmental friendliness. However, they still suffer from kinetic problems associated with the solid-state diffusion of sodium ions during charge and discharge processes, which leads to low specific capacity and poor rate performances. In this work, novel sodium iron hexacyanoferrate nanospheres with a hierarchical hollow architecture have been fabricated as cathode material for sodium-ion batteries by a facile template method. Due to the unique hollow sphere morpholog~ sodium iron hexacyanoferrate nanospheres can provide large numbers of active sites and high diffusion dynamics for sodium ions, thus delivering a high specific capacity (142 mAh/g), a superior rate capabili, and an excellent cycling stability. Furthermore, the sodium insertion/extraction mechanism has been studied by in situ X-ray diffraction, which provides further insight into the crystal structure change of the sodium iron hexacyanoferrate nanosphere cathode material during charge and discharge processes.
基金financially supported by the National Basic Research Program of China(Nos.2010CB934700,2013CB934004,2011CB935704)National Natural Science Foundation of China(No.11079002)
文摘SnO2 hollow nanospheres were successfully synthesized via a facile one-step solvothermal method.Characterizations show that the as-prepared SnO2 spheres are of hollow structure with a diameter at around 50 nm,and especially,the shell of the spheres is assembled by single layer SnO2 nanocrystals.The surface area of the material reaches up to 202.5 m^2/g.As an anode material for Li ion batteries,the sample exhibited improved electrochemical performance compared with commercial SnO2 particles.After cycled at high current rate of 0.5 C,1 C and 0.5 C for 20 cycles,respectively,the electrode can maintain a capacity of 509 mAh/g.The suitable shell thickness/diameter ratio endows the good structural stability of the material during cycling,which promises the excellent cycling performance of the electrode.The large surface area and the ultra thin shell ensure the high rate performance of the material.
基金the National Natural Science Foundation of China(No.51802029)Natural Science Foundation of Hunan Province,China(No.2017JJ3343)+2 种基金Scientific Research Fund of Hunan Provincial Education Department(No.17B028)Project of Changsha bureau of science and technology(No.k1705062)Scientific Research for The Introduction of Talents of Changsha University(No.SF1606).
文摘Although lithium-sulfur batteries are one of promising rechargeable energy storage devices,their wide applications are impeded by the lithium polysulfides shutle effect,low electronic conductivity of the cathode,and sluggish redox reaction kinetics of lithium polysulfides.In this work,reduced graphene oxide was decorated with CoSe2 hollow nanospheres to form an RGO-CoSe2 composite that was used as a host material to support S in the cathode.The RGO-CoSe2 composite has the following superiorities:(1)enhanced electronic conductity,(2)accommodation of the volumetric change of cathode materials,(3)effective confinement of numerous lithium polysulfides species due to chemisorption,(4)expedition of the redox kinetics of lithium polysulfides.As expected,the RGO-CoSez-based cathode exhibited the reversible specific capacity of 1,044.7 mAh/g at 0.2C and 695.7 mAh/g at 2C,together with ecellent cycling stability of 0.071% average capacity decay per cycle over 400 cycles at 1C.
基金supported by the National Natural Science Foundation of China(21271021,51472025,21671016)Beijing Nova Programme Interdisciplinary Cooperation Project
文摘Size tunable cobalt hollow nanospheres with high catalytic activity for the ammonia borane(AB) hydrolysis have been synthesized by using the solvothermal method. The complexation between Co2+and ethylenediamine is observed to be critical for the formation of the cobalt hollow nanospherical structure.The morphology of the cobalt hollow nanospheres can be regulated by adjusting the original ethylenediamine/ethanol volume ratio, reaction time and temperature. Impressively, the magnetic property study reveals that the coercivity of the as-synthesized cobalt hollow nanospheres is much enhanced compared with that of bulk cobalt materials. Meanwhile, Co/Pt bimetal hollow nanospheres(Co Pt HS) and graphene-cobalt hollow composite nanospheres(Co HS-r GO) have also been explored. In comparison with the cobalt hollow nanospheres, both the Co Pt HS and Co HS-r GO show higher catalytic activities and better repeatability for the catalytic hydrogen generation from AB hydrolysis. Moreover, it is noted that these catalysts could be recycled by using the magnetic separation method.
基金financially supported by the National Natural Science Foundation of China(No.21476063)Guizhou Provincial Education Department(No.KY[2018]031)+2 种基金the Project of Hubei Provincial Science&Technology Department(No.2018ACA147)the Open-End Fund for Hubei Key Laboratory of Pollutant Analysis&Reuse Technology(No.PA200104)the China Scholarship Council(CSC)for scholarship support。
文摘Hollow micro-/nanostructures have achieved great success in the field of renewable battery materials by reducing the volume change and promoting the ion transport.Double-shelled Co_(3)V_(2)O__(8)hollow nanospheres(CVODSS)were synthesized using a facile solvothermal method followed by a thermal treatment in the absence of any surfactant.Meanwhile,two other architectures of hollow nanospheres and nanoparticles were obtained by changing the annealing temperature.Benefiting from the desired hollow structure,the CVO-DSS electrode exhibits excellent lithium storage properties as an anode.It exhibits a reversible discharge capacity of 1210 m Ah·g^(-1)at200 m A·g^(-1)after 100 cycles and a satisfactorily high rate capacity of 628 m Ah·g^(-1)after 800 cycles at 5000 m A·g^(-1).These hollow nanostructures can efficiently enhance the contact area of the electrolyte/electrode interface,promote the diffusion of lithium ions and electrons and slow down the capacity loss during long cycles.
基金This work was supported by the National Natural Science Foundation of China(Nos.51874243,51271148,and 50971100)the Research Fund of State Key Laboratory of Solidification Processing(NPU),China(No.2020-TS-02)+1 种基金the Project of Transformation of Scientific and Technological Achievements of NWPU(No.19-2017)the Open Fund of State Key Laboratory of Advanced Technology for Material Synthesis and Processing(Wuhan University of Technology,No.2018KF-18).
文摘The widespread commercial application of direct formate fuel cell(DFFC)is limited by the lack of efficient electrocatalysts for the formate oxidation reaction(FOR).AgPdCo hollow nanospheres(H-NSs)with jagged surfaces are successfully synthesized via a facile method involving the wet-chemical synthesis of AgPdCo nanospheres(NSs)and galvanic replacement reaction between Pd salt and AgPdCo NSs.Surpassing Ag_(30)Pd_(69)Co_(1) NSs and most of previously reported electrocatalysts,Ag_(9)Pd_(90)Co_(1) H-NSs exhibit extremely high FOR activity with a peak current density of 3.08 A·mg_(Pd)^(−1).Apart from the competitive activity,Ag_(9)Pd_(90)Co_(1) H-NSs show greatly improved chronoamperometric and cycling stability,whereby the current density retains about 0.24 A·mg_(Pd)^(−1) after 3,600 s electrocatalysis and the mass activity maintains 54.06%of the initial value after 500 cycles.The unique hollow nanosphere and synergistic effect are responsible for the enhanced activity and stability.This study will provide new clues for the development of outstanding electrocatalysts.
文摘As a newly discovered member of the ttmgstate famil3~ InWO4 hollow nanospheres with a monoclinic wolframite structure were synthesized successfully. The crystal phase of InWO4 was investigated via a combination of CASTEP geometric optimization and experimental simulation. InWO, has a space group of P2/c with two InWO, formula units per unit cell. The optimized cell dimensions are a = 5.16 A, b = 5.97 A, and c = 5.23 A, with a = 90°, β= 92.11°, 7 = 90°, giving a unit cell volume of 161.10 A^3, which is consistent with the experimental measurements. More importantly, InWO4 was a promising host material for different Ln^3+ (Ln = Eu and Yb/Er) ions. For InWO4:Yb^3+/Er^3+ excited at 980 nm, transitions from the ^4G11/2 (384 nm), ^2H9/2 (411 nm), and ^4F7/2 (487 nm) levels to the ground state (^4I15/2) of Er^3+ were observed. In addition to the aforementioned properties, the InWO4 hollow nanospheres can be used to improve the performance of dye-sensitized solar cells, which is chiefly attributed to their light scattering.
基金supported by the National Natural Science Foundation of China(Nos.21978110,51772126,and 52171210)the Jilin Province Science and Technology Department Program(Nos.20200201187JC,20190201309JC,and YDZJ202101ZYTS047)+1 种基金the“13thfive-year”Science and Technology Project of Jilin Provincial Education Department(Nos.JJKH20200407KJ and JJKH20210444KJ)the Jilin Province Development and Reform Commission Program(No.2020C026-3)。
文摘The large overpotential for conventional Li-O_(2) batteries is an enormous challenge,which impedes their practical application.Here,we prepare a defective TiO_(2)(Ov-TiO_(2)) hollow nanosphere as photoelectrocatalyst for photo-assisted Li-O_(2) batteries to reduce the overpotential.Under illumination,the oxygen vacancies as a charge separation center contribute to the separation of electrons and holes.The generated electrons could promote reducing O_(2) to Li_(2)O_(2) during oxygen reduction reaction(ORR)process,while the generated holes are beneficial to Li_(2)O_(2) decomposition during oxygen evolution reaction(OER)process.Additionally,the proper concentration of oxygen vacancies will decrease the recombination rate between electrons and holes.The photo-assisted Li-O_(2) batteries with Ov-TiO_(2)-650 exhibit advanced performances,such as the low overpotential(0.70 V),the fine rate capability,and the considerable reversibility accompanied with the formation/decomposition of Li_(2)O_(2).We expect that these results could open a new mind to design of highly efficient photo-electrocatalysts for photo-assisted Li-O_(2) battery.
基金financially supported by the National Natural Science Foundation of China(Nos.21866012,61764003 and 41763015)the Basic and Applied Basic Research Program of Hainan Province(No.2019RC023)+1 种基金the Major Science and Technology Planning Project of Hainan Province(No.ZDKJ201810)the Scientific Research Foundation of Hainan University(No.kyqd1659)。
文摘The construction of built-in electric field is generally considered as an effective strategy to enhance photocatalytic performance due to its significant role in charge separation.Herein,a built-in electric field within g-C_(3)N_4 hollow nanospheres co-doped with sulfur and oxygen and modified in-situ Ni_(2)P is proposed.Ni_(2)P/SO-HC_(3)N_4 exhibits significantly enhanced board spectrum photocatalytic properties for hydrogen precipitation(5.21 mmol h^(-1)g^(-1))and photocatalytic Cr(VI)reduction without the use of noble metal.It also achieves high photocatalytic sterilization activity and remarkable stability when used to completely inactivate E.coli(10~7)in 60 min under Vis-NIR light irradiation.The enhanced performance is attributed to the formation of a curved hollow sphere structure,which promotes the electron transfer between the inner and outer layers.In addition,co-doping inhibits the recombination of photogenerated carriers,and the built-in electric field recombined with Ni_(2)facilitates the electron transfer between the composite interfaces.This design strategy demonstrates an original method of devising multifunctional photocatalysts with enhanced activity and stability.
文摘The TiO2 hollow nanospheres with diameters of about 230 nm were prepared by a simple and controllable route based on hydrolysis of Ti(OBu)4 on the surfaces of the Cu20 solid nanospheres followed by inward etching of the Cu20 nanospheres. The as-prepared samples were characterized by X-ray diffraction, transmis- sion electron microscopy and scanning electron micro- scopy. The further post-heat treatment led to the high crystallization of the TiO2 hollow nanospheres. The photocatalytic performances of these samples were evaluated for the photodegradation of rhodamine B (RhB) under UV-light irradiation. The as-prepared TiO2 hollow nanospheres showed higher photocatalytic activity than the CuO and the CuO/TiO2 hollow nanospheres. Effects of temperature and time for post-heat treatment of TiO2 as well as initial RhB concentrations on the RhB photodegradation have also been studied. The results show that the TiO2 hollow nanospheres have the good reusability as photocatalysts and are promising in waste water treatment.