Listeria monocytogenes(LM)is a dangerous foodborne pathogen for humans.One emerging and validated method of indirectly assessing LM in food is detecting 3-hydroxy-2-butanone(3H2B)gas.In this study,the synthesis of 3-(...Listeria monocytogenes(LM)is a dangerous foodborne pathogen for humans.One emerging and validated method of indirectly assessing LM in food is detecting 3-hydroxy-2-butanone(3H2B)gas.In this study,the synthesis of 3-(2-aminoethylamino)propyltrimethoxysilane(AAPTMS)functionalized hierarchical hollow TiO_(2)nanospheres was achieved via precise controlling of solvothermal reaction temperature and post-grafting route.The sensors based on as-prepared materials exhibited excellent sensitivity(480 Hz@50 ppm),low detection limit(100 ppb),and outstanding selectivity.Moreover,the evaluation of LM with high sensitivity and specificity was achieved using the sensors.Such stable three-dimensional spheres,whose distinctive hierarchical and hollow nanostructure simultaneously improved both sensitivity and response/recovery speed dramatically,were spontaneously assembled by nanosheets.Meanwhile,the moderate loadings of AAPTMS significantly improved the selectivity of sensors.Then,the gas-sensing mechanism was explored by utilizing thermodynamic investigation,Gaussian 16 software,and in situ diffuse reflectance infrared transform spectroscopy,illustrating the weak chemisorption between the-NHgroup and 3H2B molecules.These portable sensors are promising for real-time assessment of LM at room temperature,which will make a magnificent contribution to food safety.展开更多
Treatment of precious metals in electronic waste has attracted tremendous attention and is essential for both environmental protection and resource sustainable development.In this study,a novel adsorbent for precious ...Treatment of precious metals in electronic waste has attracted tremendous attention and is essential for both environmental protection and resource sustainable development.In this study,a novel adsorbent for precious metal ions,V_(2)O_(3)spiny hollow nanospheres(pV_(2)O_(3)SHN),was synthe sized through a one-step hydrothermal-as sis ted methodology for the adsorption of Au(Ⅲ),Ag(Ⅰ),Pd(Ⅱ),and Pt(Ⅳ) from the leaching solution of electronic waste.The results reveal that the p-V2O3SHN hierarchy was successfully constructed with a hollow structure and dense spiny morphology.The prepared p-V2O3SHN can effectively remove precious metal ions such as Au(Ⅲ),Ag(Ⅰ),Pd(Ⅱ),and Pt(Ⅳ),with the selective capture order being Au(Ⅲ)> Ag(Ⅰ)> Pt(Ⅳ)> Pd(Ⅱ)> other metal ions.This superior adsorption capability can be attributed to the multi-diffusible,intermingled composition,and numerous active sites decorating the p-V2O3SHN hierarchy,facilitating the uptake of Au(Ⅲ),Ag(Ⅰ),Pd(Ⅱ),and Pt(Ⅳ) ions from electronic waste.The Langmuir model provided a better fit for the uptake process,revealing maximum uptake capacities of 833.33 mg/g for Au(Ⅲ),370.37 mg/g for Ag(Ⅰ),42.01 mg/g for Pd(Ⅱ),and 77.51 mg/g for Pt(Ⅳ) on p-V_(2)O_(3)SHN.Remarkably,p-V_(2)O_(3)SHN exhibited a robust affinity for the adsorbate due to the presence of surface defects and reduction reactions.The new p-V2O3SHN also demonstrated good reusability for three sorption cycles,highlighting its potential for electronic waste treatment.Due to its facile synthesis and excellent efficiency,hierarchical p-V2O3SHN presents itself as a promising candidate for the selective uptake of Au(Ⅲ),Ag(Ⅰ),Pt(Ⅳ),and Pd(Ⅱ) from electronic waste.展开更多
The two-dimensional(2D)layered material molybdenum disulfide(MoS_(2))exhibits a special Mo-S-Mo sandwich structure with a rather large spacing,making it a promising candidate as an anode material for sodium storage ap...The two-dimensional(2D)layered material molybdenum disulfide(MoS_(2))exhibits a special Mo-S-Mo sandwich structure with a rather large spacing,making it a promising candidate as an anode material for sodium storage applications.Unfortunately,the practical applications are limited by their intrinsically low electrical conductivity,significant volume alteration and severe particle agglomeration.In this study,we designed a new two-step solvothermal strategy to synthesize ultrathin nanosheetassembled MoS_(2)hollow nanospheres strongly located onlignite-based carbon(MoS_(2)/C)without any template.The ultrathin nanosheets assembled into hollow structures mitigated the volume changes of MoS_(2)during the(dis)-charge cycles,facilitated Na+diffusion,and reduced the migration energy barrier within MoS_(2).Lignite-based C enhances the electrical conductivity of MoS_(2),prevents its aggregation,and alleviates mechanical stress during repeated(dis)charging.The resultant hollow spherical MoS_(2)/C composite exhibits outstanding cyclability and rate performance when used as an anode in sodium-ion batteries,as it delivers a high specific capacity of 515.8 mAh g^(-1)after 1000 cycles at 1.0 A g^(-1),with a 94.34%capacity retention rate.Even at a high current density of 20 Ag^(-1),a capacity of 431 mAh g^(-1)can still be obtained after 2000cycles.In particular,the initial Coulombic efficiency of the MoS_(2)anode is markedly enhanced by the incorporation of lignite-based C.展开更多
Activating both metal and lattice oxygen sites for efficient oxygen evolution reactions(OER)is a critical challenge.This study pioneers a novel approach,employing cobalt-nickel glycerate solid spheres(CoNi-G SSs)as se...Activating both metal and lattice oxygen sites for efficient oxygen evolution reactions(OER)is a critical challenge.This study pioneers a novel approach,employing cobalt-nickel glycerate solid spheres(CoNi-G SSs)as self-sacrificial templates to synthesize yolk-shell structured CoNi-G SSs@ZIF-67 nanospheres.The derived NiCo2S4@CoS2/MoS2 double-shelled hollow nanospheres integrate the adsorbate evolution mechanism(AEM)and lattice oxygen mechanism(LOM),enabling synergistic dual catalytic pathways.Nickel modulation facilitates active species reconstruction in NiCo_(2)S_(4),enhancing lattice oxygen activity and optimizing the LOM pathway.Characterization results indicate that anode activation triggered the redox processes of metal and lattice oxygen sites,involving the formation and re-filling of oxygen vacancies.Additionally,the CoS_(2)/MoS_(2) heterostructure enhances the AEM pathway,as supported by density functional theory calculations,which demonstrate optimized adsorption of intermediates for both hydrogen evolution reaction and OER.The assembled anion exchange membrane water splitting device can deliver a catalytic current of 500 mA cm^(-2) at 1.74 V under commercial catalytic operating conditions(1 mol L^(-1) KOH)for 150 h,with negligible degradation.This work provides important insights into the understanding of OER mechanisms and the design of high-performance water-splitting electrocatalysts,while also opening new avenues for developing multifunctional materials with multi-shell structures.展开更多
Constructing unique and highly stable structures with plenty of electroactive sites in sodium storage materials is a key factor for achieving improved electrochemical properties through favorable sodium ion di usion k...Constructing unique and highly stable structures with plenty of electroactive sites in sodium storage materials is a key factor for achieving improved electrochemical properties through favorable sodium ion di usion kinetics. An SnS_2@carbon hollow nanospheres(SnS_2@C) has been designed and fabricated via a facile solvothermal route, followed by an annealing treatment. The SnS_2@C hybrid possesses an ideal hollow structure, rich active sites, a large electrode/electrolyte interface, a shortened ion transport pathway, and, importantly, a bu er space for volume change, generated from the repeated insertion/extraction of sodium ions. These merits lead to the significant reinforcement of structural integrity during electrochemical reactions and the improvement in sodium storage properties, with a high specific reversible capacity of 626.8 mAh g^(-1) after 200 cycles at a current density of 0.2 A g^(-1) and superior high-rate performance(304.4 mAh g^(-1) at 5 A g^(-1)).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
Searching for highly efficient catalysts toward dehydrogenation of hydrazine for chemical hydrogen storage is highly desirable for the development of hydrogen economy. Herein, we report a simple in situ co-reduction s...Searching for highly efficient catalysts toward dehydrogenation of hydrazine for chemical hydrogen storage is highly desirable for the development of hydrogen economy. Herein, we report a simple in situ co-reduction synthesis of NiPt nanoparticles supported on CeO_2 nanospheres and their superior catalytic performance for hydrogen generation from alkaline solution of hydrazine at room temperature. Thanks to the strong electronic interaction arising from synergistic effect at atomic lever and support-metal interaction between NiPt and CeO_2.The obtained Ni_5Pt_5-CeO_2 catalyst exhibits 100% hydrogen selectivity and superior catalytic performance for hydrogen generation from alkaline solution of hydrazine at room temperature, with a TOF value of 416 h 1.展开更多
Lithium-ion hybrid capacitors(LIHCs)have drawn extensive attention in fleld of energy storage.However,the absence of appropriate electrode materials with rapid kinetics restricted the overall performance of the capaci...Lithium-ion hybrid capacitors(LIHCs)have drawn extensive attention in fleld of energy storage.However,the absence of appropriate electrode materials with rapid kinetics restricted the overall performance of the capacitors.Herein,hierarchical N,P-codoped hollow car-bon nanospheres coupling with WS_(2) nanosheets(N,P-codoped HCNS/WS_(2)NSs)were fabricated for boosting lithium storage materials.Specially,the WS_(2) nanosheets with several layers embedded in the N,P-codoped hollow carbon nanospheres could not only enhance the conduc-tivity of composites,but also provide abundant channels for the rapid transfer of ions.As a result,as-prepared N,P-codoped HCNS/WS_(2) NSs demonstrated superior rate performance and long-term cycling stability.The reversible discharge capacity of 725.2 mAh·g^(-1) could be preserved after 1000 cycles at a current density of 1.0 A·g^(-1).Fur-thermore,LIHCs devices were assembled by using N,P-codoped HCNS/WS_(2) NSs and activated carbon(AC)as the cathode and anode,which exhibited high energy density of 166.7 Wh·kg^(-1) and power density of 5312.4 W·kg^(-1).Last but not least,the capacity almost had no obvious deterioration after 6000 cycles at a high current density of 10.0 A·g^(-1).展开更多
A series of Z-schemeβ-Bi_(2)O_(3)/ZrO_(2)hetero-junction composites containing three-dimensional(3D)mesoporous silica nanospheres(MSNs)were synthesized as efficient catalysts for antibiotic remediation.The obtained M...A series of Z-schemeβ-Bi_(2)O_(3)/ZrO_(2)hetero-junction composites containing three-dimensional(3D)mesoporous silica nanospheres(MSNs)were synthesized as efficient catalysts for antibiotic remediation.The obtained MSN/β-Bi_(2)O_(3)/ZrO_(2)ternary composites possess novel lamellar cross structure,which is well constructed byβ-Bi_(2)O_(3)nanosheets,3D MSNs,and ZrO_(2)nanoparticles.The optimal sample BZS-2(Bi∶Zr∶Si=1∶0.4∶0.33)shows an adsorptive-photocatalytic removal efficiency of 92.7%towards levofloxacin(LVF)and a total organic carbon(TOC)removal efficiency of 60.0%under simu-lated solar light irradiation for 100 min.BZS-2 can also remove 90.1%and 91.2%of tetracycline hydrochloride(TC)and oxytetracycline hydrochloride(OTC),respectively,and themaximum adsorptioncapacityof TCover BZS-2is almost 10 times that of-BiO.Theimprovement ofphotocatalytic activitycan bemainly attributed to the enhanced visible-light adsorption capacity and more efficientseparationof photogenerated electron-hole pairs.A possible Z-scheme photocatalytic mechanism of p BiO/ZrOheterojunctions based on valence band offset(AEvBo)andconduction band offset(EcBo)isproposed.This study provides an efficient way to construct novel mesoporous ternary photocatalyst with increased accessible surface area and active sites for treatment of antibiotics by synergistic adsorption and photocatalysis.展开更多
Lignin is the most abundant and important macromolecule in organic matter and its yield is second only to cellulose. Lignin is abundant in source, low in price, and has a large number of active groups such as methoxy ...Lignin is the most abundant and important macromolecule in organic matter and its yield is second only to cellulose. Lignin is abundant in source, low in price, and has a large number of active groups such as methoxy group and carboxyl group, so it has great utilization value. We used lignin as a carbon source to prepare porous carbon nanosphere(PCN) materials, and in-situ synthesized the MoS_ 2 on its surface. The high specific surface area(462.8 m^2/g), large pore volume and good electron conductivity of the porous carbon scaffold facilitated the reversible electro-chemical reaction of S towards metallic Li, and thus the nano-hybrid showed a high specific energy and excellent cycle stability which still remained 520m Ah/g after 50 cycles.展开更多
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 branched core-shell nanosphere composed of an anatase TiO_(2)(a-TiO_(2)) core and a TiO_(2)nanobranch shell with gradient-doped N(a-TiO_(2)@N-TiO_(2)) is synthesized by a simple in situ doping method, in which mixed...A branched core-shell nanosphere composed of an anatase TiO_(2)(a-TiO_(2)) core and a TiO_(2)nanobranch shell with gradient-doped N(a-TiO_(2)@N-TiO_(2)) is synthesized by a simple in situ doping method, in which mixed crystal anatase-rutile TiO_(2)(ar-TiO_(2)) nanosphere is first prepared by oxidizing Ti using H_(2)O_(2), and then is etched by NH_(3)·H_(2)O to form(NH_(4))2TiO_(3)nanobranches, which is converted into a-TiO_(2)@N-TiO_(2)following an ambient annealing process. The diameter of a-TiO_(2)core is ~500 nm, and the thickness of NTiO_(2)branched shell is ~100 nm with gradually increased N concentration from the bottom to the edge.Ultra-thin amorphous coating layers on the branches are also observed. The morphology of the composites could be further tuned by the amount of NH_(3)·H_(2)O, and its effect on the photocatalytic performance is also investigated. The optimized a-TiO_(2)@N-TiO_(2)shows an outstanding hydrogen evolution rate of 308.1 μmol g^(-1)h^(-1)under air mass(AM) 1.5 illumination, and also exhibits highly active in photocatalytic degradation of various refractory organic pollutants, including organic dyes, phenols, antibiotics,and personal care products, with removal ratios higher than 96% after 2 h operation. This can be due to the gradient-doped N-TiO_(2)nanobranches, which not only provide bending band structure and defect level derived from the N impurities and O vacancies, resulting the formation of n-n+heterojunctions to improve the charge separation, but also enhance the charge transfer at the liquid-solid interface due to the numerous nanobranches and amorphous coating layers.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
Cerium oxide(CeO_(2)) has attracted much attention in recent years owing to its reversible switch ability in Ce^(3+)/Ce^(4+)redox to produce improved antioxidation properties for biomedical applications.Here,we report...Cerium oxide(CeO_(2)) has attracted much attention in recent years owing to its reversible switch ability in Ce^(3+)/Ce^(4+)redox to produce improved antioxidation properties for biomedical applications.Here,we report to embed the CeO_(2)nanospheres into the organic polymer network using electrostatic spinning technology to prepare polyvinyl alcohol(PVA)-encapsulated CeO_(2)nanospheres composite nanofibrous membranes(PVA-CeO_(2)) for the first time,which is beneficial to improving the dispersion and biocompatibility of CeO_(2)nanosphere without altering the original antioxidant properties of CeO_(2).Detailed characterization of the as-prepared composite nanofibrous membranes reveals that CeO_(2)was successfully introduced into the PVA fibers with strong interactions,thus enhancing the thermal stability and fracture toughness of the nanoifbers.As a result,PVA-CeO_(2)exhibits superior UV shielding performance,antioxidant performance and bacteriostatic performance.Meaningfully,PVA-CeO_(2)has strong absorbance in both UVA and UVB bands when the CeO_(2)concentration in the nanoifber membrane reaches 1.5 wt%,and shows an excellent scavenging effect on the 2,2-diphenyl-1-picrylhydrazyl(DPPH)radicals with a scavenging rate of 86.52%.Moreover,the Kirby-Bauer(K-B) method of agar diffusion test further confirms that PVA-CeO_(2)has antimicrobial ability against three types of representative strains,including Gram-positive bacteria(Staphylococcus aureus),Gram-negative bacteria(Escherichia coli) and fungi(Candida albicans).Importantly,no obvious cytotoxicity is observed for PVA-CeO_(2)even though the amount of embedded CeO_(2)nanosphere reaches as high as 1.5 wt%.This study reveals new avenues for improving the future smart design of CeO_(2)-based nanoifber membrane composite materials for biological antioxidants.展开更多
Constructing electrode materials with large capacity and good conductivity is an effective approach to improve the capacitor performance of asymmetric supercapacitors(ASCs).In this paper,ZnCo_(2)S_(4)core-shell nanosp...Constructing electrode materials with large capacity and good conductivity is an effective approach to improve the capacitor performance of asymmetric supercapacitors(ASCs).In this paper,ZnCo_(2)S_(4)core-shell nanospheres are constructed by two-step hydrothermal method.In order to improve the chemical activity of ZnCo_(2)S_(4),ZnCo_(2)S_(4)is activated using cetyltrimethylammonium bromide(CTAB).Then,MXene nanosheets are fixed on the surface of ZnCo_(2)S_(4)by electrostatic selfassembly method to improve the specific surface area of ZnCo_(2)S_(4)and MXene-wrapped ZnCo_(2)S_(4)composite is prepared in this work.Owing to the synergy effect between MXene nanosheets and ZnCo_(2)S_(4)core-shell nanospheres,the as-prepared composite displays fast ion transfer rate and charge/discharge process.The capacity of the MXenewrapped ZnCo_(2)S_(4)composite can reach 1072 F·g^(-1),which is far larger than that of ZnCo_(2)S_(4)(407 F·g^(-1))at 1 A·g^(-1).An ASC device is assembled,which delivers 1.7 V potential window and superior cyclic stability(95.41%capacitance retention).Furthermore,energy density of this device is up to 30.46 Wh·kg^(-1)at a power density of850 W·kg^(-1).The above results demonstrate that MXenewrapped ZnCo_(2)S_(4)composite has great application prospects in electrochemical energy storage field.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
Through uncomplicated carbonation process,a carbon-embedded CoNiSe_(2)/C nanosphere was synthesized from Ni-Co-MOF (metal-organic framework) precursor whose controllable structure and synergistic effect of bimetallic ...Through uncomplicated carbonation process,a carbon-embedded CoNiSe_(2)/C nanosphere was synthesized from Ni-Co-MOF (metal-organic framework) precursor whose controllable structure and synergistic effect of bimetallic Ni/Co brought CoNiSe_(2)/C anodes with high specific surface area (172.79 m^(2)/g) and outstanding electrochemical performance.CoNiSe_(2)/C anodes obtained reversible discharge capacities of850.9 mAh/g at 0.1 A/g after cycling for 100 cycles.In addition,CoNiSe_(2)/C exhibits excellent cycle stability and reversibility in the rate test at a current density of 0.1–2.0 A/g.When the current density returns to 0.5 A/g for 150 cycles,its discharge ratio the capacity is 330.8 m Ah/g.Electrochemical impedance spectroscopy (EIS) tests suggested that CoNiSe_(2)/C anodes had a lower charge transfer impedance of 130.02Ωafter 30 cycles.In-situ X-ray diffraction (XRD) tests confirmed the alloying mechanism of CoNiSe_(2)/C which realized higher lithium storage capacity.This work affords substantial evidence for the extension of bimetallic selenides in secondary batteries,promoting the development of bimetallic selenides in anode materials for LIBs.展开更多
We demonstrate a simple and highly efficient strategy to synthesize MnO2/nitrogen-doped ultramicroporous carbon nanospheres（MnO2/N-UCNs） for supercapacitor application.MnO2/N-UCNs were fabricated via a template-free...We demonstrate a simple and highly efficient strategy to synthesize MnO2/nitrogen-doped ultramicroporous carbon nanospheres（MnO2/N-UCNs） for supercapacitor application.MnO2/N-UCNs were fabricated via a template-free polymerization of resorcinol/formaldehyde on the surface of phloroglucinol/terephthalaldehyde colloids in the presence of hexamethylenetetramine,followed by carbonization and then a redox reaction between carbons and KMnO4.As-prepared MnO2/N-UCNs exhibits regular ultramicropores,high surface area,nitrogen heteroatom,and high content of MnO2.A typical MnO2/N-UCNs with 57 wt.%MnO2 doping content（denoted as MnO2（57%）/N-UCNs） makes the most use of the synergistic effect between carbons and metal oxides.MnO2（57%）/N-UCNs as a supercapacitor electrode exhibits excellent electrochemical performance such as a high specific capacitance（401 F/g at 1.0 A/g） and excellent charge/discharge stability（86.3%of the initial capacitance after 10,000 cycles at 2.0 A/g） in 1.0 mol/L Na2SO4 electrolyte.The well-designed and high-performance MnO2/N-UCNs highlight the great potential for advanced supercapacitor applications.展开更多
Potassium ion batteries(PIBs) have been regarded as promising alternatives to lithium ion batteries(LIBs)on account of their abundant resource and low cost in large scale energy storage applications. However,it still ...Potassium ion batteries(PIBs) have been regarded as promising alternatives to lithium ion batteries(LIBs)on account of their abundant resource and low cost in large scale energy storage applications. However,it still remains great challenges to explore suitable electrode materials that can reversibly accommodate large size of potassium ions. Here, we construct oxygen-deficient V_(2)O_(3)nanoparticles encapsulated in amorphous carbon shell(Od-V_(2)O_(3)@C) as anode materials for PIBs by subtly combining the strategies of morphology and deficiency engineering. The MOF derived nanostructure along with uniform carbon coating layer can not only enables fast K+migration and charge transfer kinetics, but also accommodate volume change and maintain structural stability. Besides, the introduction of oxygen deficiency intrinsically tunes the electronic structure of materials according to DFT calculation, and thus lead to improved electrochemical performance. When utilized as anode for PIBs, Od-V_(2)O_(3)@C electrode exhibits superior rate capability(reversible capacities of 262.8, 227.8, 201.5, 179.8, 156.9 mAh/g at 100, 200, 500, 1000 and2000 mA/g, respectively), and ultralong cycle life(127.4 mAh/g after 1000 cycles at 2 A/g). This study demonstrates a feasible way to realize high performance PIBs through morphology and deficiency engineering.展开更多
Paper-based sensing platform is a point of need analytical toolkit for safety testing.However,the sensitivity,specificity,and simplicity are still challenging.Herein,we report a novel strategy(Au/δ-MnO_(2) hollow nan...Paper-based sensing platform is a point of need analytical toolkit for safety testing.However,the sensitivity,specificity,and simplicity are still challenging.Herein,we report a novel strategy(Au/δ-MnO_(2) hollow nanosphere and 3,3′,5,5′-tetramethylbenzidine(TMB)induced test strips for signal-on detection)that can be utilized for hexavalent chromium(Cr^(6+))detection.Interestingly,Cr^(6+)(CrO_(4)^(2−)) as a smart switch can remarkably enhance the oxidase-like activity of Au/δ-MnO_(2) hollow nanosphere.The presence of Cr^(6+) can regulate the surface electronic redistribution of Au/δ-MnO_(2) and adjust the geometric configuration,which leads to the improvement in oxidase-like activity of Au/δ-MnO_(2).As a proof-of-concept application,a visual paper-based sensing platform of Cr^(6+) along with quantitative analysis by the test strips was successfully constructed.This paper-based sensing platform exhibits a linear range with excellent selectivity for other interfering substances and lower limit of detection of 0.09μmol·L^(−1),providing a promising toolkit at-home Cr^(6+) measurement and environmental monitoring.展开更多
基金supported by the National Natural Science Foundation of China(No.32272399)the Shanghai Natural Science Foundation(No.21ZR1427500).
文摘Listeria monocytogenes(LM)is a dangerous foodborne pathogen for humans.One emerging and validated method of indirectly assessing LM in food is detecting 3-hydroxy-2-butanone(3H2B)gas.In this study,the synthesis of 3-(2-aminoethylamino)propyltrimethoxysilane(AAPTMS)functionalized hierarchical hollow TiO_(2)nanospheres was achieved via precise controlling of solvothermal reaction temperature and post-grafting route.The sensors based on as-prepared materials exhibited excellent sensitivity(480 Hz@50 ppm),low detection limit(100 ppb),and outstanding selectivity.Moreover,the evaluation of LM with high sensitivity and specificity was achieved using the sensors.Such stable three-dimensional spheres,whose distinctive hierarchical and hollow nanostructure simultaneously improved both sensitivity and response/recovery speed dramatically,were spontaneously assembled by nanosheets.Meanwhile,the moderate loadings of AAPTMS significantly improved the selectivity of sensors.Then,the gas-sensing mechanism was explored by utilizing thermodynamic investigation,Gaussian 16 software,and in situ diffuse reflectance infrared transform spectroscopy,illustrating the weak chemisorption between the-NHgroup and 3H2B molecules.These portable sensors are promising for real-time assessment of LM at room temperature,which will make a magnificent contribution to food safety.
基金supported by the Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.ES202306).
文摘Treatment of precious metals in electronic waste has attracted tremendous attention and is essential for both environmental protection and resource sustainable development.In this study,a novel adsorbent for precious metal ions,V_(2)O_(3)spiny hollow nanospheres(pV_(2)O_(3)SHN),was synthe sized through a one-step hydrothermal-as sis ted methodology for the adsorption of Au(Ⅲ),Ag(Ⅰ),Pd(Ⅱ),and Pt(Ⅳ) from the leaching solution of electronic waste.The results reveal that the p-V2O3SHN hierarchy was successfully constructed with a hollow structure and dense spiny morphology.The prepared p-V2O3SHN can effectively remove precious metal ions such as Au(Ⅲ),Ag(Ⅰ),Pd(Ⅱ),and Pt(Ⅳ),with the selective capture order being Au(Ⅲ)> Ag(Ⅰ)> Pt(Ⅳ)> Pd(Ⅱ)> other metal ions.This superior adsorption capability can be attributed to the multi-diffusible,intermingled composition,and numerous active sites decorating the p-V2O3SHN hierarchy,facilitating the uptake of Au(Ⅲ),Ag(Ⅰ),Pd(Ⅱ),and Pt(Ⅳ) ions from electronic waste.The Langmuir model provided a better fit for the uptake process,revealing maximum uptake capacities of 833.33 mg/g for Au(Ⅲ),370.37 mg/g for Ag(Ⅰ),42.01 mg/g for Pd(Ⅱ),and 77.51 mg/g for Pt(Ⅳ) on p-V_(2)O_(3)SHN.Remarkably,p-V_(2)O_(3)SHN exhibited a robust affinity for the adsorbate due to the presence of surface defects and reduction reactions.The new p-V2O3SHN also demonstrated good reusability for three sorption cycles,highlighting its potential for electronic waste treatment.Due to its facile synthesis and excellent efficiency,hierarchical p-V2O3SHN presents itself as a promising candidate for the selective uptake of Au(Ⅲ),Ag(Ⅰ),Pt(Ⅳ),and Pd(Ⅱ) from electronic waste.
基金financially supported by the National Natural Science Foundation of China(Nos.51962027 and 21968022)the Major Science and Technology Project of Inner Mongolia Autonomous Region(No.2021ZD0016)+5 种基金the National Key R&D Program of China(No.2020YFC1909105)the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(No.NJYT24002)the Central Guidance Fund for Local Scientific and Technological Development(No.2024ZY0012)the Key Project of Tianjin Natural Science Foundation(No.23JCZDJC00570)the Special Funding of China Postdoctoral Science Foundation(No.2023T160268)the China Postdoctoral Science Foundation(No.2023M741362)
文摘The two-dimensional(2D)layered material molybdenum disulfide(MoS_(2))exhibits a special Mo-S-Mo sandwich structure with a rather large spacing,making it a promising candidate as an anode material for sodium storage applications.Unfortunately,the practical applications are limited by their intrinsically low electrical conductivity,significant volume alteration and severe particle agglomeration.In this study,we designed a new two-step solvothermal strategy to synthesize ultrathin nanosheetassembled MoS_(2)hollow nanospheres strongly located onlignite-based carbon(MoS_(2)/C)without any template.The ultrathin nanosheets assembled into hollow structures mitigated the volume changes of MoS_(2)during the(dis)-charge cycles,facilitated Na+diffusion,and reduced the migration energy barrier within MoS_(2).Lignite-based C enhances the electrical conductivity of MoS_(2),prevents its aggregation,and alleviates mechanical stress during repeated(dis)charging.The resultant hollow spherical MoS_(2)/C composite exhibits outstanding cyclability and rate performance when used as an anode in sodium-ion batteries,as it delivers a high specific capacity of 515.8 mAh g^(-1)after 1000 cycles at 1.0 A g^(-1),with a 94.34%capacity retention rate.Even at a high current density of 20 Ag^(-1),a capacity of 431 mAh g^(-1)can still be obtained after 2000cycles.In particular,the initial Coulombic efficiency of the MoS_(2)anode is markedly enhanced by the incorporation of lignite-based C.
文摘Activating both metal and lattice oxygen sites for efficient oxygen evolution reactions(OER)is a critical challenge.This study pioneers a novel approach,employing cobalt-nickel glycerate solid spheres(CoNi-G SSs)as self-sacrificial templates to synthesize yolk-shell structured CoNi-G SSs@ZIF-67 nanospheres.The derived NiCo2S4@CoS2/MoS2 double-shelled hollow nanospheres integrate the adsorbate evolution mechanism(AEM)and lattice oxygen mechanism(LOM),enabling synergistic dual catalytic pathways.Nickel modulation facilitates active species reconstruction in NiCo_(2)S_(4),enhancing lattice oxygen activity and optimizing the LOM pathway.Characterization results indicate that anode activation triggered the redox processes of metal and lattice oxygen sites,involving the formation and re-filling of oxygen vacancies.Additionally,the CoS_(2)/MoS_(2) heterostructure enhances the AEM pathway,as supported by density functional theory calculations,which demonstrate optimized adsorption of intermediates for both hydrogen evolution reaction and OER.The assembled anion exchange membrane water splitting device can deliver a catalytic current of 500 mA cm^(-2) at 1.74 V under commercial catalytic operating conditions(1 mol L^(-1) KOH)for 150 h,with negligible degradation.This work provides important insights into the understanding of OER mechanisms and the design of high-performance water-splitting electrocatalysts,while also opening new avenues for developing multifunctional materials with multi-shell structures.
基金the National Natural Science Foundation of China (Grant No. 21701144)the China Postdoctoral Science Foundation (Grant Nos. 2016M592303 and 2017T100536)
文摘Constructing unique and highly stable structures with plenty of electroactive sites in sodium storage materials is a key factor for achieving improved electrochemical properties through favorable sodium ion di usion kinetics. An SnS_2@carbon hollow nanospheres(SnS_2@C) has been designed and fabricated via a facile solvothermal route, followed by an annealing treatment. The SnS_2@C hybrid possesses an ideal hollow structure, rich active sites, a large electrode/electrolyte interface, a shortened ion transport pathway, and, importantly, a bu er space for volume change, generated from the repeated insertion/extraction of sodium ions. These merits lead to the significant reinforcement of structural integrity during electrochemical reactions and the improvement in sodium storage properties, with a high specific reversible capacity of 626.8 mAh g^(-1) after 200 cycles at a current density of 0.2 A g^(-1) and superior high-rate performance(304.4 mAh g^(-1) at 5 A g^(-1)).
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financially supported by the National Natural Science Foundation of China (No. 21571145)Large-scale Instrument and Equipment Sharing Foundation of Wuhan University
文摘Searching for highly efficient catalysts toward dehydrogenation of hydrazine for chemical hydrogen storage is highly desirable for the development of hydrogen economy. Herein, we report a simple in situ co-reduction synthesis of NiPt nanoparticles supported on CeO_2 nanospheres and their superior catalytic performance for hydrogen generation from alkaline solution of hydrazine at room temperature. Thanks to the strong electronic interaction arising from synergistic effect at atomic lever and support-metal interaction between NiPt and CeO_2.The obtained Ni_5Pt_5-CeO_2 catalyst exhibits 100% hydrogen selectivity and superior catalytic performance for hydrogen generation from alkaline solution of hydrazine at room temperature, with a TOF value of 416 h 1.
基金the National Natural Science Foundation of China(Nos.51902266 and 22002003)the Innovation Foundation for Doctor Dissertation of Northwestern Poly technical University(No.CX2021009)+1 种基金the Key Research and Development Projects of Shaanxi Province(No.2020GXLH-Z-032)the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(No.G8QT0461G),and the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(No.SKLSP202004)。
文摘Lithium-ion hybrid capacitors(LIHCs)have drawn extensive attention in fleld of energy storage.However,the absence of appropriate electrode materials with rapid kinetics restricted the overall performance of the capacitors.Herein,hierarchical N,P-codoped hollow car-bon nanospheres coupling with WS_(2) nanosheets(N,P-codoped HCNS/WS_(2)NSs)were fabricated for boosting lithium storage materials.Specially,the WS_(2) nanosheets with several layers embedded in the N,P-codoped hollow carbon nanospheres could not only enhance the conduc-tivity of composites,but also provide abundant channels for the rapid transfer of ions.As a result,as-prepared N,P-codoped HCNS/WS_(2) NSs demonstrated superior rate performance and long-term cycling stability.The reversible discharge capacity of 725.2 mAh·g^(-1) could be preserved after 1000 cycles at a current density of 1.0 A·g^(-1).Fur-thermore,LIHCs devices were assembled by using N,P-codoped HCNS/WS_(2) NSs and activated carbon(AC)as the cathode and anode,which exhibited high energy density of 166.7 Wh·kg^(-1) and power density of 5312.4 W·kg^(-1).Last but not least,the capacity almost had no obvious deterioration after 6000 cycles at a high current density of 10.0 A·g^(-1).
基金financially supported by National Natural Science Foundation of China (Nos.21962006, 21607064 and 21707055)the Youth Key Project of Natural Science Foundation of Jiangxi Province (Nos.20192ACBL20014 and 20192ACBL21011)+1 种基金the Natural Science Foundation of Jiangxi Province (Nos.20181BAB203018 and 20181BAB213010)Qingjiang Excellent Young Talents of Jiangxi University of Science and Technology
文摘A series of Z-schemeβ-Bi_(2)O_(3)/ZrO_(2)hetero-junction composites containing three-dimensional(3D)mesoporous silica nanospheres(MSNs)were synthesized as efficient catalysts for antibiotic remediation.The obtained MSN/β-Bi_(2)O_(3)/ZrO_(2)ternary composites possess novel lamellar cross structure,which is well constructed byβ-Bi_(2)O_(3)nanosheets,3D MSNs,and ZrO_(2)nanoparticles.The optimal sample BZS-2(Bi∶Zr∶Si=1∶0.4∶0.33)shows an adsorptive-photocatalytic removal efficiency of 92.7%towards levofloxacin(LVF)and a total organic carbon(TOC)removal efficiency of 60.0%under simu-lated solar light irradiation for 100 min.BZS-2 can also remove 90.1%and 91.2%of tetracycline hydrochloride(TC)and oxytetracycline hydrochloride(OTC),respectively,and themaximum adsorptioncapacityof TCover BZS-2is almost 10 times that of-BiO.Theimprovement ofphotocatalytic activitycan bemainly attributed to the enhanced visible-light adsorption capacity and more efficientseparationof photogenerated electron-hole pairs.A possible Z-scheme photocatalytic mechanism of p BiO/ZrOheterojunctions based on valence band offset(AEvBo)andconduction band offset(EcBo)isproposed.This study provides an efficient way to construct novel mesoporous ternary photocatalyst with increased accessible surface area and active sites for treatment of antibiotics by synergistic adsorption and photocatalysis.
基金the financial support of National Natural Science Foundation of China (No. 51803062)National Natural Science Foundation of Guangdong Province (No. 2018A030310379)+4 种基金National Postdoctoral Program for Innovation Talents (No. BX201700079)China Postdoctoral Science Foundation Funded Project (No. 2017M620371)and Foundation for Distinguished Young Talents in Higher Education of Guangdong Province (No. 2017KQNCX001)F. Chen thanks the financialsupport of Natural Science Foundation of China (No. 51673175)Natural Science Foundation of Zhejiang Province (Nos. LY16E030012, LY17E030006 and LY18E030009)
文摘Lignin is the most abundant and important macromolecule in organic matter and its yield is second only to cellulose. Lignin is abundant in source, low in price, and has a large number of active groups such as methoxy group and carboxyl group, so it has great utilization value. We used lignin as a carbon source to prepare porous carbon nanosphere(PCN) materials, and in-situ synthesized the MoS_ 2 on its surface. The high specific surface area(462.8 m^2/g), large pore volume and good electron conductivity of the porous carbon scaffold facilitated the reversible electro-chemical reaction of S towards metallic Li, and thus the nano-hybrid showed a high specific energy and excellent cycle stability which still remained 520m Ah/g after 50 cycles.
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supported by the National Natural Science Foundation of China (No. 52170083)the Excellent Youth Fund Project of Natural Science Foundation of Hunan Province (No.2021JJ20007)the Research Foundation of Education Bureau of Hunan Province,China (No. 21B0441)。
文摘A branched core-shell nanosphere composed of an anatase TiO_(2)(a-TiO_(2)) core and a TiO_(2)nanobranch shell with gradient-doped N(a-TiO_(2)@N-TiO_(2)) is synthesized by a simple in situ doping method, in which mixed crystal anatase-rutile TiO_(2)(ar-TiO_(2)) nanosphere is first prepared by oxidizing Ti using H_(2)O_(2), and then is etched by NH_(3)·H_(2)O to form(NH_(4))2TiO_(3)nanobranches, which is converted into a-TiO_(2)@N-TiO_(2)following an ambient annealing process. The diameter of a-TiO_(2)core is ~500 nm, and the thickness of NTiO_(2)branched shell is ~100 nm with gradually increased N concentration from the bottom to the edge.Ultra-thin amorphous coating layers on the branches are also observed. The morphology of the composites could be further tuned by the amount of NH_(3)·H_(2)O, and its effect on the photocatalytic performance is also investigated. The optimized a-TiO_(2)@N-TiO_(2)shows an outstanding hydrogen evolution rate of 308.1 μmol g^(-1)h^(-1)under air mass(AM) 1.5 illumination, and also exhibits highly active in photocatalytic degradation of various refractory organic pollutants, including organic dyes, phenols, antibiotics,and personal care products, with removal ratios higher than 96% after 2 h operation. This can be due to the gradient-doped N-TiO_(2)nanobranches, which not only provide bending band structure and defect level derived from the N impurities and O vacancies, resulting the formation of n-n+heterojunctions to improve the charge separation, but also enhance the charge transfer at the liquid-solid interface due to the numerous nanobranches and amorphous coating layers.
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Project supported by the National Natural Science Foundation of China (22301012)the R&D Program of Beijing Municipal Education Commission (KM202310011005)。
文摘Cerium oxide(CeO_(2)) has attracted much attention in recent years owing to its reversible switch ability in Ce^(3+)/Ce^(4+)redox to produce improved antioxidation properties for biomedical applications.Here,we report to embed the CeO_(2)nanospheres into the organic polymer network using electrostatic spinning technology to prepare polyvinyl alcohol(PVA)-encapsulated CeO_(2)nanospheres composite nanofibrous membranes(PVA-CeO_(2)) for the first time,which is beneficial to improving the dispersion and biocompatibility of CeO_(2)nanosphere without altering the original antioxidant properties of CeO_(2).Detailed characterization of the as-prepared composite nanofibrous membranes reveals that CeO_(2)was successfully introduced into the PVA fibers with strong interactions,thus enhancing the thermal stability and fracture toughness of the nanoifbers.As a result,PVA-CeO_(2)exhibits superior UV shielding performance,antioxidant performance and bacteriostatic performance.Meaningfully,PVA-CeO_(2)has strong absorbance in both UVA and UVB bands when the CeO_(2)concentration in the nanoifber membrane reaches 1.5 wt%,and shows an excellent scavenging effect on the 2,2-diphenyl-1-picrylhydrazyl(DPPH)radicals with a scavenging rate of 86.52%.Moreover,the Kirby-Bauer(K-B) method of agar diffusion test further confirms that PVA-CeO_(2)has antimicrobial ability against three types of representative strains,including Gram-positive bacteria(Staphylococcus aureus),Gram-negative bacteria(Escherichia coli) and fungi(Candida albicans).Importantly,no obvious cytotoxicity is observed for PVA-CeO_(2)even though the amount of embedded CeO_(2)nanosphere reaches as high as 1.5 wt%.This study reveals new avenues for improving the future smart design of CeO_(2)-based nanoifber membrane composite materials for biological antioxidants.
基金financially supported by the Fundamental Research Funds for the Central Universities (No. 2019XKQYMS16)
文摘Constructing electrode materials with large capacity and good conductivity is an effective approach to improve the capacitor performance of asymmetric supercapacitors(ASCs).In this paper,ZnCo_(2)S_(4)core-shell nanospheres are constructed by two-step hydrothermal method.In order to improve the chemical activity of ZnCo_(2)S_(4),ZnCo_(2)S_(4)is activated using cetyltrimethylammonium bromide(CTAB).Then,MXene nanosheets are fixed on the surface of ZnCo_(2)S_(4)by electrostatic selfassembly method to improve the specific surface area of ZnCo_(2)S_(4)and MXene-wrapped ZnCo_(2)S_(4)composite is prepared in this work.Owing to the synergy effect between MXene nanosheets and ZnCo_(2)S_(4)core-shell nanospheres,the as-prepared composite displays fast ion transfer rate and charge/discharge process.The capacity of the MXenewrapped ZnCo_(2)S_(4)composite can reach 1072 F·g^(-1),which is far larger than that of ZnCo_(2)S_(4)(407 F·g^(-1))at 1 A·g^(-1).An ASC device is assembled,which delivers 1.7 V potential window and superior cyclic stability(95.41%capacitance retention).Furthermore,energy density of this device is up to 30.46 Wh·kg^(-1)at a power density of850 W·kg^(-1).The above results demonstrate that MXenewrapped ZnCo_(2)S_(4)composite has great application prospects in electrochemical energy storage field.
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supported by National Natural Science Foundation, China (Nos. 52071132, 21773057 and U1904216)Zhongyuan Thousand People Plan-The Zhongyuan Youth Talent Support Program (in Science and Technology), China (No. ZYQR201810139)+1 种基金Innovative Funds Plan of Henan University of Technology, China (No. 2020ZKCJ04)Fundamental Research Funds for the Henan Provincial Colleges and Universities in Henan University of Technology, China (No. 2018RCJH01)。
文摘Through uncomplicated carbonation process,a carbon-embedded CoNiSe_(2)/C nanosphere was synthesized from Ni-Co-MOF (metal-organic framework) precursor whose controllable structure and synergistic effect of bimetallic Ni/Co brought CoNiSe_(2)/C anodes with high specific surface area (172.79 m^(2)/g) and outstanding electrochemical performance.CoNiSe_(2)/C anodes obtained reversible discharge capacities of850.9 mAh/g at 0.1 A/g after cycling for 100 cycles.In addition,CoNiSe_(2)/C exhibits excellent cycle stability and reversibility in the rate test at a current density of 0.1–2.0 A/g.When the current density returns to 0.5 A/g for 150 cycles,its discharge ratio the capacity is 330.8 m Ah/g.Electrochemical impedance spectroscopy (EIS) tests suggested that CoNiSe_(2)/C anodes had a lower charge transfer impedance of 130.02Ωafter 30 cycles.In-situ X-ray diffraction (XRD) tests confirmed the alloying mechanism of CoNiSe_(2)/C which realized higher lithium storage capacity.This work affords substantial evidence for the extension of bimetallic selenides in secondary batteries,promoting the development of bimetallic selenides in anode materials for LIBs.
基金financially supported by the National Natural Science Foundation of China(Nos.21273162,21473122,21501135)the Science and Technology of Shanghai Municipality,China(No.14DZ2261100)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Large Equipment Test Foundation of Tongji University
文摘We demonstrate a simple and highly efficient strategy to synthesize MnO2/nitrogen-doped ultramicroporous carbon nanospheres（MnO2/N-UCNs） for supercapacitor application.MnO2/N-UCNs were fabricated via a template-free polymerization of resorcinol/formaldehyde on the surface of phloroglucinol/terephthalaldehyde colloids in the presence of hexamethylenetetramine,followed by carbonization and then a redox reaction between carbons and KMnO4.As-prepared MnO2/N-UCNs exhibits regular ultramicropores,high surface area,nitrogen heteroatom,and high content of MnO2.A typical MnO2/N-UCNs with 57 wt.%MnO2 doping content（denoted as MnO2（57%）/N-UCNs） makes the most use of the synergistic effect between carbons and metal oxides.MnO2（57%）/N-UCNs as a supercapacitor electrode exhibits excellent electrochemical performance such as a high specific capacitance（401 F/g at 1.0 A/g） and excellent charge/discharge stability（86.3%of the initial capacitance after 10,000 cycles at 2.0 A/g） in 1.0 mol/L Na2SO4 electrolyte.The well-designed and high-performance MnO2/N-UCNs highlight the great potential for advanced supercapacitor applications.
基金financial support from the National Natural Science Foundation of China(Nos.51922042 and 51872098)Fundamental Research Funds for Central Universities,China(No.2020ZYGXZR074)the Scientific and Technological Plan of Qingyuan City,China(2019DZX008)。
文摘Potassium ion batteries(PIBs) have been regarded as promising alternatives to lithium ion batteries(LIBs)on account of their abundant resource and low cost in large scale energy storage applications. However,it still remains great challenges to explore suitable electrode materials that can reversibly accommodate large size of potassium ions. Here, we construct oxygen-deficient V_(2)O_(3)nanoparticles encapsulated in amorphous carbon shell(Od-V_(2)O_(3)@C) as anode materials for PIBs by subtly combining the strategies of morphology and deficiency engineering. The MOF derived nanostructure along with uniform carbon coating layer can not only enables fast K+migration and charge transfer kinetics, but also accommodate volume change and maintain structural stability. Besides, the introduction of oxygen deficiency intrinsically tunes the electronic structure of materials according to DFT calculation, and thus lead to improved electrochemical performance. When utilized as anode for PIBs, Od-V_(2)O_(3)@C electrode exhibits superior rate capability(reversible capacities of 262.8, 227.8, 201.5, 179.8, 156.9 mAh/g at 100, 200, 500, 1000 and2000 mA/g, respectively), and ultralong cycle life(127.4 mAh/g after 1000 cycles at 2 A/g). This study demonstrates a feasible way to realize high performance PIBs through morphology and deficiency engineering.
基金This work was financially supported by Xuzhou science and technology plan project of China(No.KC21294).
文摘Paper-based sensing platform is a point of need analytical toolkit for safety testing.However,the sensitivity,specificity,and simplicity are still challenging.Herein,we report a novel strategy(Au/δ-MnO_(2) hollow nanosphere and 3,3′,5,5′-tetramethylbenzidine(TMB)induced test strips for signal-on detection)that can be utilized for hexavalent chromium(Cr^(6+))detection.Interestingly,Cr^(6+)(CrO_(4)^(2−)) as a smart switch can remarkably enhance the oxidase-like activity of Au/δ-MnO_(2) hollow nanosphere.The presence of Cr^(6+) can regulate the surface electronic redistribution of Au/δ-MnO_(2) and adjust the geometric configuration,which leads to the improvement in oxidase-like activity of Au/δ-MnO_(2).As a proof-of-concept application,a visual paper-based sensing platform of Cr^(6+) along with quantitative analysis by the test strips was successfully constructed.This paper-based sensing platform exhibits a linear range with excellent selectivity for other interfering substances and lower limit of detection of 0.09μmol·L^(−1),providing a promising toolkit at-home Cr^(6+) measurement and environmental monitoring.
