Volatile Organic Compounds(VOCs)are highly harmful to human beings and other organisms,and thus the elimination of VOCs is extremely urgent.Here,La-Si co-doped TiO_(2)microsphere photocatalysts,which were prepared by ...Volatile Organic Compounds(VOCs)are highly harmful to human beings and other organisms,and thus the elimination of VOCs is extremely urgent.Here,La-Si co-doped TiO_(2)microsphere photocatalysts,which were prepared by a hydrothermal method,exhibited high photocatalytic activity in the decomposition of formaldehyde compared with TiO_(2).The improved activity can be attributed to the promoted separation efficiency and density of the charge carriers,as verified by the electrochemical results in combination with density functional theory calculations.In addition,the Si dopant changed the microstructure and surface acidity,while the addition of La promoted the separation efficiency of charge carriers.More interestingly,it was found that singlet oxygen was the key species in the activation of molecular dioxygen,and it played a pivotal role in the photocatalytic decomposition of formaldehyde.This work provides a novel strategy for the selective activation of dioxygen for use in the decomposition of formaldehyde.展开更多
Real-time detection of acetic acid vapor is of concern for ensuring environmental and personal safety.However,acetic acid gas sensors,particularly those based on Bi_(2)O_(3),often fail to meet practical performance re...Real-time detection of acetic acid vapor is of concern for ensuring environmental and personal safety.However,acetic acid gas sensors,particularly those based on Bi_(2)O_(3),often fail to meet practical performance requirements owing to their slow response characteristics and high operating temperature.To enhance sensing performance,highly permeable Bi_(2)O_(3)microspheres decorated by Pt-nanoparticles are rationally synthesized by a facile template method.Among the fabricated sensors,the one based on 3 wt%Pt-decorated Bi_(2)O_(3)demonstrated excellent sensing performance.Specifically,the sensor displayed high selectivity for acetic acid,rapid response and recovery times(22.5 and 9 s,respectively),strong resistance to interference,and good long-term stability at a low operating temperature(150℃).Notably,the sensor exhibited an exceptionally high response of 126 to 100 ppm acetic acid—the highest reported value for Bi_(2)O_(3)-based sensors tested at a relatively low operating temperature in recent years.These results demonstrate that Pt-decorated Bi_(2)O_(3)holds strong potential for use in high-performance acetic acid sensors.展开更多
Hollow Bi2WO6 microspheres are successfully synthesized by a facile ultrasonic spray pyrolysis（USP） method using NaCl as a salt template.The as-prepared hollow microspheres assembled as nanoplates with dimensions of...Hollow Bi2WO6 microspheres are successfully synthesized by a facile ultrasonic spray pyrolysis（USP） method using NaCl as a salt template.The as-prepared hollow microspheres assembled as nanoplates with dimensions of approximately 41-148 nm and are dispersed with non-uniform pores on the template surface.By swapping the salt template with KC1 or Na2SO4,different morphologies of Bi2WO6 are obtained.The experimental results demonstrate that NaCl plays a key role on the formation of Bi2WO6 with hollow structures.The specific growth mechanism of hollow microspheres was studied in detail.The Bi2WO6 hollow microspheres exhibit an excellent photocatalytic efficiency for NO removal under solar light irradiation,which is 1.73 times higher than for the Bi2WO6 obtained in the absence of any salt template.This enhancement can be ascribed to the simultaneous improvement on the surface area and visible light-harvesting ability from the hollow structures.Electron spin resonance（ESR） results suggest that both radicals of ·OH and ·O2^- are involved in the photocatalytic process over the BWO-NaCl sample.The production of ·O2^- radicals offers better durability for NO removal.展开更多
A molten salt method was developed to prepare porous La1‐xSrxMn0.8Fe0.2O3 （0≤ x ≤ 0.6） micro‐spheres using hierarchical porous δ‐MnO2 microspheres as a template in eutectic NaNO3‐KNO3. X‐ray diffraction patt...A molten salt method was developed to prepare porous La1‐xSrxMn0.8Fe0.2O3 （0≤ x ≤ 0.6） micro‐spheres using hierarchical porous δ‐MnO2 microspheres as a template in eutectic NaNO3‐KNO3. X‐ray diffraction patterns showed that single phase LaMn0.8Fe0.2O3 with good crystallinity was syn‐thesized at 450℃ after 4 h. Transmission electron microscope images exhibited that the LaMn0.8Fe0.2O3 sample obtained at 450？？ after 4 h possessed a porous spherical morphology com‐posed of aggregated nanocrystallites. Field emission scanning electron microscope images indicated that the growth of the porous LaMn0.8Fe0.2O3 microspheres has two stages. SEM pictures showed that a higher calcination temperature than 450？？ had an adverse effect on the formation of a po‐rous spherical structure. The LaMn0.8Fe0.2O3 sample obtained at 450？？ after 4 h displayed a high BET surface area of 55.73 m2/g with a pore size of 9.38 nm. Fourier transform infrared spectra suggested that Sr2＋ions entered the A sites and induced a decrease of the binding energy between Mn and O. The CO conversion with the La1‐xSrxMn0.8Fe0.2O3 （0≤x≤0.6） samples indicated that the La0.4Sr0.6Mn0.8Fe0.2O3 sample had the best catalytic activity and stability. Further analysis by X‐ray photoelectron spectroscopy demonstrated that Sr2＋doping altered the content of Mn4＋ions, oxygen vacancies and adsorbed oxygen species on the surface, which affected the catalytic performance for CO oxidation.展开更多
Spinel LiMn2O4 microspheres with durable high rate capability were synthesized by a facile route using spherical MnCO3 precursors as the self-supported templates, combined with the calcinations of LiNO3 at 700 °C...Spinel LiMn2O4 microspheres with durable high rate capability were synthesized by a facile route using spherical MnCO3 precursors as the self-supported templates, combined with the calcinations of LiNO3 at 700 °C for 8 h. The spherical MnCO3 precursors were obtained from the control of the crystallizing process of Mn2＋ ions and NH4HCO3 in aqueous solution. The effects of the mole ratio of the raw materials, reaction time, and reaction temperature on the morphology and yield of the MnCO3 were investigated. The as-synthesized MnCO3 and LiMn2O4 microspheres were characterized by powder X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. Galvanostatic charge/discharge tests indicate that the spinel LiMn2O4 microspheres deliver a discharge capacity of 90 mA-h/g at 10C rate show good capacity retention capability （75% of their initial capacity after 800 cycles at 10C rate）. The durable high rate capability suggests that the as-synthesized LiMn2O4 microspheres are promising cathode materials for high power lithium ion batteries.展开更多
Converting solar energy into chemical energy by artificial photosynthesis is promising in addressing the issues of the greenhouse effect and fossil fuel crisis.Herein,a novel photocatalyst,i.e.CdS/TiO_(2) hollow micro...Converting solar energy into chemical energy by artificial photosynthesis is promising in addressing the issues of the greenhouse effect and fossil fuel crisis.Herein,a novel photocatalyst,i.e.CdS/TiO_(2) hollow microspheres(HS),were dedicatedly designed to boost overall photocatalytic efficiency.TiO_(2) nanoparticles were in-situ decorated on the inside and outside the shell of Cd S HS,ensuring close contact between TiO_(2) and CdS.The CdS/TiO2 HS with abundant mesopores inside of the shell boost the light absorption via multiscattering effect as well as accessible to reactions in all directions.The heterojunction was scrutinized and the charge transfer across it was revealed by in-situ irradiated X-ray photoelectron spectroscopy(ISI-XPS).Ultimately,the charge transfer in this composite was determined to follow stepscheme mechanism,which not only facilitates the separation of charge carriers but also preserves strong redox ability.Benefited from the intimate linkage between Cd S and TiO_(2) and the favorable step-scheme heterojunction,enhanced photocatalytic CO_(2) reduction activity was accomplished.The CH4 yield rate of CdS/TiO_(2) reaches 27.85μmol g^(–1) h^(–1),which is 145.6 and 3.8 times higher than those of pristine CdS and TiO_(2),respectively.This work presents a novel insight into constructing step-scheme photocatalytic system with desirable performance.展开更多
As promising energy storage systems,lithium-sulfur(Li-S)batteries have attracted significant attention because of their ultra-high energy densities.However,Li-S battery suffers problems related to the complex phase co...As promising energy storage systems,lithium-sulfur(Li-S)batteries have attracted significant attention because of their ultra-high energy densities.However,Li-S battery suffers problems related to the complex phase conversion that occurs during the charge-discharge process,particularly the deposition of solid Li2S from the liquid-phase polysulfides,which greatly limits its practical application.In this paper,edge-rich MoS2/C hollow microspheres(Edg-MoS2/C HMs)were designed and used to functionalize separator for Li-S battery,resulting in the uniform deposition of Li2S.The microspheres were fabricated through the facile hydrothermal treatment of MoO3-aniline nanowires and a subsequent carbonization process.The obtained Edg-MoS2/C HMs have a strong chemical absorption capability and high density of Li2S binding sites,and exhibit excellent electrocatalytic performance and can effectively hinder the polysulfide shuttle effect and guide the uniform nucleation and growth of Li2S.Furthermore,we demonstrate that the Edg-MoS2/C HMs can effectively regulate the deposition of Li2S and significantly improve the reversibility of the phase conversion of the active sulfur species,especially at high sulfur loadings and high C-rates.As a result,a cell containing a separator functionalized with Edg-MoS2/C HMs exhibited an initial discharge capacity of 935 mAh g-1 at 1.0 C and maintained a capacity of 494 mAh g-1 after 1000 cycles with a sulfur loading of 1.7 mg cm-2.Impressively,at a high sulfur loading of 6.1 mg cm-2 and high rate of 0.5 C,the cell still delivered a high reversible discharge capacity of 478 mAh g-1 after 300 cycles.This work provides fresh insights into energy storage systems related to complex phase conversions.展开更多
In this work,MoS2@montmorillonite nanosheets hollow microspheres(MoS2@MMTNS-HMS)with a novel morphology structure was successfully synthesized through loading MoS2 to the surface of MMTNS-HMS via hydrothermal method.T...In this work,MoS2@montmorillonite nanosheets hollow microspheres(MoS2@MMTNS-HMS)with a novel morphology structure was successfully synthesized through loading MoS2 to the surface of MMTNS-HMS via hydrothermal method.The novel material has been characterized through the measurements of SEM,TEM,Raman spectra and UV–vis absorption spectra.The results have shown that MoS2@MMTNS-HMS emerges higher light-utilization efficiency,density of edge active sites and separation of photoelectrons,owing to its unique hollow structure,vertically-aligned MoS2 nanosheets,which greatly enhances its photocatalytic activity.Furthermore,the cycle stability of MoS2@MMTNS-HMS is much higher than that of pristine MoS2,which is attributed to that MMTNS-HMS greatly inhibits the oxidation of MoS2 during photocatalytic.MoS2@MMTNS-HMS could be a promising photocatalyst for the applications in the elimination of organic pollutants.展开更多
Constructing a step-scheme heterojunction at the interface between two semiconductors is an efficient way to optimize the redox ability and accelerate the charge carrier separation of a photocatalytic system for achie...Constructing a step-scheme heterojunction at the interface between two semiconductors is an efficient way to optimize the redox ability and accelerate the charge carrier separation of a photocatalytic system for achieving high photocatalytic performance.In this study,we prepared a hierarchical ZnO@ZnS step-scheme photocatalyst by incorporating ZnS into the outer shell of hollow ZnO microspheres via a simple in situ sulfidation strategy.The ZnO@ZnS step-scheme photocatalysts had a large surface area,high light utilization capacity,and superior separation efficiency for photogenerated charge carriers.In addition,the material simulation revealed that the formation of the step-scheme heterojunction between ZnO and ZnS was due to the presence of the built-in electric field.Our study paves the way for design of high-performance photocatalysts for H_(2) production.展开更多
High-performance microwave-absorbing materials(MAMs)should meet both impedance matching and attenuation performance.Commonly,it is hard to maintain excellent microwave absorption(MA)per-formance at an elevated tempera...High-performance microwave-absorbing materials(MAMs)should meet both impedance matching and attenuation performance.Commonly,it is hard to maintain excellent microwave absorption(MA)per-formance at an elevated temperature because the reliance on impedance matching and dielectric loss about temperature mutually restricts.In this work,the pomegranate-like antimony-doped tin dioxide(ATO)/silica dioxide(SiO_(2))spheres were fabricated via a simple spray drying process.When the spheres were used as functional units and dispersed in the matrix,the corresponding composites exhibit an out-standing anti-reflection effect on microwaves.Moreover,the unique pomegranate-like structure of the ATO/SiO_(2)spheres provides both the effective local eddy current and abundant heterogeneous interface,which therefore contribute harvest enhanced dielectric relaxation and improved absorption performance when compared with that of the corresponding ATO/SiO_(2)composition.As a result,the maximum re-flection loss of the ATO/SiO_(2)spheres composites can reach-47.8 dB at 9.7 GHz with a thickness of 1.8 mm,while the reflection loss could reach-47.3 dB at 573 K and the effective absorption bandwidth is 2.4 GHz.This work reveals the importance of local eddy current loss in optimizing the electromagnetic wave(EMW)absorption performance and impedance matching,providing novel guidance on designing advanced high-temperature MAMs.展开更多
Hierarchical Sb_2S_3 hollow microspheres assembled by nanowires have been successfully synthesized by a simple and practical hydrothermal reaction. The possible formation process of this architecture was investigated ...Hierarchical Sb_2S_3 hollow microspheres assembled by nanowires have been successfully synthesized by a simple and practical hydrothermal reaction. The possible formation process of this architecture was investigated by X-ray diffraction, focused-ion beam-scanning electron microscopy dual-beam system, and transmission electron microscopy. When used as the anode material for lithium-ion batteries, Sb_2S_3 hollow microspheres manifest excellent rate property and enhanced lithium-storage capability and can deliver a discharge capacity of 674 m Ah g^(-1) at a current density of 200 m A g^(-1) after 50 cycles. Even at a high currentdensity of 5000 m A g^(-1), a discharge capacity of541 m Ah g^(-1) is achieved. Sb_2S_3 hollow microspheres also display a prominent sodium-storage capacity and maintain a reversible discharge capacity of 384 m Ah g^(-1) at a current density of 200 m A g^(-1) after 50 cycles. The remarkable lithium/sodium-storage property may be attributed to the synergetic effect of its nanometer size and three-dimensional hierarchical architecture, and the outstanding stability property is attributed to the sufficient interior void space,which can buffer the volume expansion.展开更多
Development of efficient heterostructured photocatalysts that respond to visible light remains a considerable challenge.We herein show the synthesis of ZnIn2S4/carbon quantum dot hybrid photocatalysts with flowerlike ...Development of efficient heterostructured photocatalysts that respond to visible light remains a considerable challenge.We herein show the synthesis of ZnIn2S4/carbon quantum dot hybrid photocatalysts with flowerlike microspheres via a facile solvothermal method.The ZnIn2S4/carbon quantum dot flowerlike microspheres display enhanced photocatalytic and photoelectrochemical activity compared with that of pure ZnIn2S4.With a content of only 0.5 wt%carbon quantum dots,93%of Cr(VI)is reduced under visible‐light irradiation at 40 min.As a co‐catalyst,the carbon quantum dots improve the light absorption and lengthen the lifetime of charge carriers,consequently enhancing the photocatalytic and photoelectrochemical activity.展开更多
Porous CeO2 hollow microspheres were successfully prepared through a facile process by using the rape pollen as the biotemplate. Scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, the N2 a...Porous CeO2 hollow microspheres were successfully prepared through a facile process by using the rape pollen as the biotemplate. Scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, the N2 adsorption and desorption, X-ray diffraction （XRD）, UV-vis diffuse reflectance spectra, and hydrogen temperature-programmed reduction （H2-TPR） were used for their characterization. The results showed that the obtained materials exhibited the same morphology as that of the pollen template, with a diameter of ca. 10 μm, and the surface was evenly covered with a special network-like structutre with mesh size of about 0.3 μm, and the Brunauer-Emmett-Teller （BET） surface area was measured to be 156 m2/g. The detailed property investigation inferred that the product exhibited better photocatalytic activity in acid fuchsine decolorization under daylight because of higher surface area, smaller crystallite size and higher oxygen capacity.展开更多
TiO2@Ni(OH)2 core-shell microspheres were synthesized by a facile strategy to obtain a perfect 3D flower-like nanostructure with well-arranged Ni(OH)2 nanoflakes on the surfaces of TiO2 microspheres;this arrangement l...TiO2@Ni(OH)2 core-shell microspheres were synthesized by a facile strategy to obtain a perfect 3D flower-like nanostructure with well-arranged Ni(OH)2 nanoflakes on the surfaces of TiO2 microspheres;this arrangement led to a six-fold enhancement in photocatalytic hydrogen evolution. The unique p-n type heterostructure not only promotes the separation and transfer of photogenerated charge carriers significantly, but also offers more active sites for photocatalytic hydrogen production. A photocatalytic mechanism is proposed based on the results of electrochemical measurements and X-ray photoelectron spectroscopy.展开更多
Hierarchically porous anatase Ti02 microspheres composited with carbonaceous species （TCS） have been successfully fabricated by a one-step template-free solvothermal method, combined with subsequent low temperature ...Hierarchically porous anatase Ti02 microspheres composited with carbonaceous species （TCS） have been successfully fabricated by a one-step template-free solvothermal method, combined with subsequent low temperature dried process. In this configuration, the TCS microspheres are constructed by the intercon- nected porous nanosheets, which are further assembled with abundant nanoparticles and carbonaceous species. Such composite microspheres possess a large specific surface area of 337 m2 g-l, uniform mesopores of 3.37 nm and high total pore volumes of 0.275 cm3 g-1. The materials exhibit the enhanced photocatalytic properties and stability for degradation of rhodamine B （RhB） under visible-light irradiation. The enhanced photocatalytic degradation performance may be ascribed to their abundant porous structure, large specific surface area and the unique assist-function of the carbonaceous species.展开更多
It is rather essential to design glorious system with high CO_(2) adsorption capacity and electron migration efficiency for improving selective and effective CO_(2) reduction into solar fuels.Here,as-synthesized pheno...It is rather essential to design glorious system with high CO_(2) adsorption capacity and electron migration efficiency for improving selective and effective CO_(2) reduction into solar fuels.Here,as-synthesized phenolic resin spheres via suspension polymerization were carbonized and activated by water vapor to obtain activated carbon spheres(ACSs).Subsequently,Bi_(2)MoO_(6)/ACSs were prepared via hydrothermal-impregnated method.The systematical characterizations of samples,including XRD,XPS,SEM,EDX,DRS,BET,PL,CO_(2) adsorption isotherm,EIS and transient photocurrent,were analyzed.The results clearly demonstrated that Bi_(2)MoO_(6) with suitable oxidation reduction potentials and bandgap and ACSs with admirable CO_(2) adsorption and electrical conductivity not only enhanced separation efficiency of photoindued electron-hole pair,but also displayed as 1.8 times CO_(2) reduction activity to CO as single Bi_(2)MoO_(6) sample under Xe-lamp irradiation.Finally,a concerned photocatalytic CO_(2) reduction mechanism was proposed and investigated.Our findings should provide innovative guidance for designing a series of photocatalytic CO_(2) reduction materials with highly efficient and selective ability.展开更多
TS-2 microspheres,consisting of intergrown primary nanocrystals,was prepared by controlling the synthetic parameters.The effects of the amount of quaternary ammonium cations as structure-directing agent,H2O/Si ratio,t...TS-2 microspheres,consisting of intergrown primary nanocrystals,was prepared by controlling the synthetic parameters.The effects of the amount of quaternary ammonium cations as structure-directing agent,H2O/Si ratio,the presence of alcohol and the temperature were carefully investigated on the crystallization process.The high alkalinity was proved to be highly important for the preservation of the microsphere morphology initially formed,due to the unique intergrown stacking style.An alkali treatment with the aqueous solution of structure-directing agent,organic amine and ammonium salt and subsequent Na+ion-exchange were performed to enhance the catalytic activity of TS-2 microsphere in the cyclohexanone ammoximation reactions,with both the conversion and selectivity higher than 99%.In the continuous reaction,the TS-2 microspheres exhibited to be durable catalyst with potential application in industrial ammoximation processes.展开更多
A novel Bi2S3 microsphere was fabricated through one-pot urea-assisted solvothermal method.The synthesized Bi2S3 microsphere was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transf...A novel Bi2S3 microsphere was fabricated through one-pot urea-assisted solvothermal method.The synthesized Bi2S3 microsphere was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transformed infrared spectroscopy(FT-IR)and thermal gravimetric analysis and differential thermal analysis(DTA-TG).Subsequently,the photocatalytic performances of Bi2S3 microsphere were evaluated by photocatalytic degradation of methyl orange(MO)simulation solution under visible-light irradiation.The results show that,Bi2S3 microsphere could be used as a potential cost-efficient catalysis for eliminating of methyl orange from aqueous solutions,whose degradation rate could reach 91.07%within 180 min.Besides,a tentative photocatalytic reaction mechanism was discussed according to the energy band position.Therefore,this work indicated a simplistic approach for the fabrication of visible-light responsive Bi2S3 microsphere photocatalyst,which can be used as a valuable candidate in solar energy conversion and environment pollution treatment.展开更多
Solar‐powered semiconductor photocatalysis is considered a powerful strategy for addressing environmental pollution and energy crisis.Nevertheless,the separation and transfer abilities of photogenerated photocatalyst...Solar‐powered semiconductor photocatalysis is considered a powerful strategy for addressing environmental pollution and energy crisis.Nevertheless,the separation and transfer abilities of photogenerated photocatalysts remain unsatisfactory.Herein,dual Ti_(3)C_(2)nanosheets/Ag co‐catalysts synergistically decorated hierarchical flower‐like TiO_(2)microspheres for boosting photocatalytic H_(2)production were fabricated by electrostatic self‐assembly and subsequent photoreduction procedures.The optimal Ag/Ti_(3)C_(2)/TiO_(2)composite demonstrated an excellent photocatalytic H_(2)‐production rate of 1024.72μmol g^(−1)h^(−1)under simulated solar irradiation,achieving nearly 40,2.3,and 1.8 folds with respect to that obtained on pristine TiO2,optimized Ti_(3)C_(2)/TiO_(2)composite,and Ag/TiO_(2)composite,respectively.The considerably improved photocatalytic H_(2)‐production activity is associated with the synergistic effect of the hierarchical flower‐like structure of TiO2,excellent electrical conductivity of Ti_(3)C_(2),and surface plasmon resonance effect of Ag,which enhances the light absorption capacity and promotes the separation and transfer of photogenerated carriers.This study provides insight into the design of high‐efficiency photocatalysts with dual co‐catalysts for solar H_(2)production.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.22076063,22076098,and 21477047)the Natural Science Foundation of Shandong Province(No.ZR2020MB033)+1 种基金the Key Laboratory of Photochemical Conversion and Optoelectronic Materials,TIPC,CAS(No.PCOM202106)the program for Taishan Scholars of Shandong Province,and the Science and Technology Programof the University of Jinan(No.XKY2111).
文摘Volatile Organic Compounds(VOCs)are highly harmful to human beings and other organisms,and thus the elimination of VOCs is extremely urgent.Here,La-Si co-doped TiO_(2)microsphere photocatalysts,which were prepared by a hydrothermal method,exhibited high photocatalytic activity in the decomposition of formaldehyde compared with TiO_(2).The improved activity can be attributed to the promoted separation efficiency and density of the charge carriers,as verified by the electrochemical results in combination with density functional theory calculations.In addition,the Si dopant changed the microstructure and surface acidity,while the addition of La promoted the separation efficiency of charge carriers.More interestingly,it was found that singlet oxygen was the key species in the activation of molecular dioxygen,and it played a pivotal role in the photocatalytic decomposition of formaldehyde.This work provides a novel strategy for the selective activation of dioxygen for use in the decomposition of formaldehyde.
基金financially supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(Nos.2022K1A3A1A20014496 and RS-2023-00284318)
文摘Real-time detection of acetic acid vapor is of concern for ensuring environmental and personal safety.However,acetic acid gas sensors,particularly those based on Bi_(2)O_(3),often fail to meet practical performance requirements owing to their slow response characteristics and high operating temperature.To enhance sensing performance,highly permeable Bi_(2)O_(3)microspheres decorated by Pt-nanoparticles are rationally synthesized by a facile template method.Among the fabricated sensors,the one based on 3 wt%Pt-decorated Bi_(2)O_(3)demonstrated excellent sensing performance.Specifically,the sensor displayed high selectivity for acetic acid,rapid response and recovery times(22.5 and 9 s,respectively),strong resistance to interference,and good long-term stability at a low operating temperature(150℃).Notably,the sensor exhibited an exceptionally high response of 126 to 100 ppm acetic acid—the highest reported value for Bi_(2)O_(3)-based sensors tested at a relatively low operating temperature in recent years.These results demonstrate that Pt-decorated Bi_(2)O_(3)holds strong potential for use in high-performance acetic acid sensors.
基金supported by the National Natural Science Foundation of China (41503102, 41401567, 41573138)the China Postdoctoral Science Foundation (2015M572568)~~
文摘Hollow Bi2WO6 microspheres are successfully synthesized by a facile ultrasonic spray pyrolysis（USP） method using NaCl as a salt template.The as-prepared hollow microspheres assembled as nanoplates with dimensions of approximately 41-148 nm and are dispersed with non-uniform pores on the template surface.By swapping the salt template with KC1 or Na2SO4,different morphologies of Bi2WO6 are obtained.The experimental results demonstrate that NaCl plays a key role on the formation of Bi2WO6 with hollow structures.The specific growth mechanism of hollow microspheres was studied in detail.The Bi2WO6 hollow microspheres exhibit an excellent photocatalytic efficiency for NO removal under solar light irradiation,which is 1.73 times higher than for the Bi2WO6 obtained in the absence of any salt template.This enhancement can be ascribed to the simultaneous improvement on the surface area and visible light-harvesting ability from the hollow structures.Electron spin resonance（ESR） results suggest that both radicals of ·OH and ·O2^- are involved in the photocatalytic process over the BWO-NaCl sample.The production of ·O2^- radicals offers better durability for NO removal.
基金supported by the National Science Foundation for Young Scientists of China (51202171)~~
文摘A molten salt method was developed to prepare porous La1‐xSrxMn0.8Fe0.2O3 （0≤ x ≤ 0.6） micro‐spheres using hierarchical porous δ‐MnO2 microspheres as a template in eutectic NaNO3‐KNO3. X‐ray diffraction patterns showed that single phase LaMn0.8Fe0.2O3 with good crystallinity was syn‐thesized at 450℃ after 4 h. Transmission electron microscope images exhibited that the LaMn0.8Fe0.2O3 sample obtained at 450？？ after 4 h possessed a porous spherical morphology com‐posed of aggregated nanocrystallites. Field emission scanning electron microscope images indicated that the growth of the porous LaMn0.8Fe0.2O3 microspheres has two stages. SEM pictures showed that a higher calcination temperature than 450？？ had an adverse effect on the formation of a po‐rous spherical structure. The LaMn0.8Fe0.2O3 sample obtained at 450？？ after 4 h displayed a high BET surface area of 55.73 m2/g with a pore size of 9.38 nm. Fourier transform infrared spectra suggested that Sr2＋ions entered the A sites and induced a decrease of the binding energy between Mn and O. The CO conversion with the La1‐xSrxMn0.8Fe0.2O3 （0≤x≤0.6） samples indicated that the La0.4Sr0.6Mn0.8Fe0.2O3 sample had the best catalytic activity and stability. Further analysis by X‐ray photoelectron spectroscopy demonstrated that Sr2＋doping altered the content of Mn4＋ions, oxygen vacancies and adsorbed oxygen species on the surface, which affected the catalytic performance for CO oxidation.
基金Project(2011M501090) upported by the China Postdoctoral Science FoundationProject(SCUT2012ZZ0042) upported by the Fundamental Research Funds for the Central Universities+1 种基金Project supported by the"SPR-2011"of South China University of TechnologyProject(NRC07/08.EG01)supprted by the Fok Ying Tung Foundation
文摘Spinel LiMn2O4 microspheres with durable high rate capability were synthesized by a facile route using spherical MnCO3 precursors as the self-supported templates, combined with the calcinations of LiNO3 at 700 °C for 8 h. The spherical MnCO3 precursors were obtained from the control of the crystallizing process of Mn2＋ ions and NH4HCO3 in aqueous solution. The effects of the mole ratio of the raw materials, reaction time, and reaction temperature on the morphology and yield of the MnCO3 were investigated. The as-synthesized MnCO3 and LiMn2O4 microspheres were characterized by powder X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. Galvanostatic charge/discharge tests indicate that the spinel LiMn2O4 microspheres deliver a discharge capacity of 90 mA-h/g at 10C rate show good capacity retention capability （75% of their initial capacity after 800 cycles at 10C rate）. The durable high rate capability suggests that the as-synthesized LiMn2O4 microspheres are promising cathode materials for high power lithium ion batteries.
基金financially supported by the National Natural Science Foundation of China(NSFC)(Nos.51872220,51932007,51961135303,21871217,U1905215 and U1705251)the National Key Research and Development Program of China(No.2018YFB1502001)the Fundamental Research Funds for the Central Universities(No.WUT:2019IVB050)。
文摘Converting solar energy into chemical energy by artificial photosynthesis is promising in addressing the issues of the greenhouse effect and fossil fuel crisis.Herein,a novel photocatalyst,i.e.CdS/TiO_(2) hollow microspheres(HS),were dedicatedly designed to boost overall photocatalytic efficiency.TiO_(2) nanoparticles were in-situ decorated on the inside and outside the shell of Cd S HS,ensuring close contact between TiO_(2) and CdS.The CdS/TiO2 HS with abundant mesopores inside of the shell boost the light absorption via multiscattering effect as well as accessible to reactions in all directions.The heterojunction was scrutinized and the charge transfer across it was revealed by in-situ irradiated X-ray photoelectron spectroscopy(ISI-XPS).Ultimately,the charge transfer in this composite was determined to follow stepscheme mechanism,which not only facilitates the separation of charge carriers but also preserves strong redox ability.Benefited from the intimate linkage between Cd S and TiO_(2) and the favorable step-scheme heterojunction,enhanced photocatalytic CO_(2) reduction activity was accomplished.The CH4 yield rate of CdS/TiO_(2) reaches 27.85μmol g^(–1) h^(–1),which is 145.6 and 3.8 times higher than those of pristine CdS and TiO_(2),respectively.This work presents a novel insight into constructing step-scheme photocatalytic system with desirable performance.
基金financially supported by National Natural Science Foundation of China (No. 51672083)Program of Shanghai Academic/Technology Research Leader (18XD1401400)+3 种基金Basic Research Program of Shanghai (17JC1404702)Leading talents in Shanghai in 2018The 111 project (B14018)the Fundamental Research Funds for the Central Universities (222201718002)
文摘As promising energy storage systems,lithium-sulfur(Li-S)batteries have attracted significant attention because of their ultra-high energy densities.However,Li-S battery suffers problems related to the complex phase conversion that occurs during the charge-discharge process,particularly the deposition of solid Li2S from the liquid-phase polysulfides,which greatly limits its practical application.In this paper,edge-rich MoS2/C hollow microspheres(Edg-MoS2/C HMs)were designed and used to functionalize separator for Li-S battery,resulting in the uniform deposition of Li2S.The microspheres were fabricated through the facile hydrothermal treatment of MoO3-aniline nanowires and a subsequent carbonization process.The obtained Edg-MoS2/C HMs have a strong chemical absorption capability and high density of Li2S binding sites,and exhibit excellent electrocatalytic performance and can effectively hinder the polysulfide shuttle effect and guide the uniform nucleation and growth of Li2S.Furthermore,we demonstrate that the Edg-MoS2/C HMs can effectively regulate the deposition of Li2S and significantly improve the reversibility of the phase conversion of the active sulfur species,especially at high sulfur loadings and high C-rates.As a result,a cell containing a separator functionalized with Edg-MoS2/C HMs exhibited an initial discharge capacity of 935 mAh g-1 at 1.0 C and maintained a capacity of 494 mAh g-1 after 1000 cycles with a sulfur loading of 1.7 mg cm-2.Impressively,at a high sulfur loading of 6.1 mg cm-2 and high rate of 0.5 C,the cell still delivered a high reversible discharge capacity of 478 mAh g-1 after 300 cycles.This work provides fresh insights into energy storage systems related to complex phase conversions.
基金The financial supports to this work from the National Natural Science Foundation of China under the projects Nos.51674183,51904215 and 51874220 are gratefully acknowledgedsupported by the Natural Science Foundation of Hubei Province of China(2018CFB468)the Excellent Dissertation Cultivation Funds of Wuhan University of Technology(2018-YS-050).
文摘In this work,MoS2@montmorillonite nanosheets hollow microspheres(MoS2@MMTNS-HMS)with a novel morphology structure was successfully synthesized through loading MoS2 to the surface of MMTNS-HMS via hydrothermal method.The novel material has been characterized through the measurements of SEM,TEM,Raman spectra and UV–vis absorption spectra.The results have shown that MoS2@MMTNS-HMS emerges higher light-utilization efficiency,density of edge active sites and separation of photoelectrons,owing to its unique hollow structure,vertically-aligned MoS2 nanosheets,which greatly enhances its photocatalytic activity.Furthermore,the cycle stability of MoS2@MMTNS-HMS is much higher than that of pristine MoS2,which is attributed to that MMTNS-HMS greatly inhibits the oxidation of MoS2 during photocatalytic.MoS2@MMTNS-HMS could be a promising photocatalyst for the applications in the elimination of organic pollutants.
文摘Constructing a step-scheme heterojunction at the interface between two semiconductors is an efficient way to optimize the redox ability and accelerate the charge carrier separation of a photocatalytic system for achieving high photocatalytic performance.In this study,we prepared a hierarchical ZnO@ZnS step-scheme photocatalyst by incorporating ZnS into the outer shell of hollow ZnO microspheres via a simple in situ sulfidation strategy.The ZnO@ZnS step-scheme photocatalysts had a large surface area,high light utilization capacity,and superior separation efficiency for photogenerated charge carriers.In addition,the material simulation revealed that the formation of the step-scheme heterojunction between ZnO and ZnS was due to the presence of the built-in electric field.Our study paves the way for design of high-performance photocatalysts for H_(2) production.
基金the financial support of the National Nature Science Foundation of China(No.U1704253).
文摘High-performance microwave-absorbing materials(MAMs)should meet both impedance matching and attenuation performance.Commonly,it is hard to maintain excellent microwave absorption(MA)per-formance at an elevated temperature because the reliance on impedance matching and dielectric loss about temperature mutually restricts.In this work,the pomegranate-like antimony-doped tin dioxide(ATO)/silica dioxide(SiO_(2))spheres were fabricated via a simple spray drying process.When the spheres were used as functional units and dispersed in the matrix,the corresponding composites exhibit an out-standing anti-reflection effect on microwaves.Moreover,the unique pomegranate-like structure of the ATO/SiO_(2)spheres provides both the effective local eddy current and abundant heterogeneous interface,which therefore contribute harvest enhanced dielectric relaxation and improved absorption performance when compared with that of the corresponding ATO/SiO_(2)composition.As a result,the maximum re-flection loss of the ATO/SiO_(2)spheres composites can reach-47.8 dB at 9.7 GHz with a thickness of 1.8 mm,while the reflection loss could reach-47.3 dB at 573 K and the effective absorption bandwidth is 2.4 GHz.This work reveals the importance of local eddy current loss in optimizing the electromagnetic wave(EMW)absorption performance and impedance matching,providing novel guidance on designing advanced high-temperature MAMs.
基金supported financially by the National Natural Foundation of China(Grant No.51672234)the Research Foundation for Hunan Youth Outstanding People from Hunan Provincial Science and Technology Department(2015RS4030)+1 种基金Hunan 2011 Collaborative Innovation Center of Chemical Engineering&Technology with Environmental Benignity and Effective Resource UtilizationProgram for Innovative Research Cultivation Team in University of Ministry of Education of China(1337304)
文摘Hierarchical Sb_2S_3 hollow microspheres assembled by nanowires have been successfully synthesized by a simple and practical hydrothermal reaction. The possible formation process of this architecture was investigated by X-ray diffraction, focused-ion beam-scanning electron microscopy dual-beam system, and transmission electron microscopy. When used as the anode material for lithium-ion batteries, Sb_2S_3 hollow microspheres manifest excellent rate property and enhanced lithium-storage capability and can deliver a discharge capacity of 674 m Ah g^(-1) at a current density of 200 m A g^(-1) after 50 cycles. Even at a high currentdensity of 5000 m A g^(-1), a discharge capacity of541 m Ah g^(-1) is achieved. Sb_2S_3 hollow microspheres also display a prominent sodium-storage capacity and maintain a reversible discharge capacity of 384 m Ah g^(-1) at a current density of 200 m A g^(-1) after 50 cycles. The remarkable lithium/sodium-storage property may be attributed to the synergetic effect of its nanometer size and three-dimensional hierarchical architecture, and the outstanding stability property is attributed to the sufficient interior void space,which can buffer the volume expansion.
文摘Development of efficient heterostructured photocatalysts that respond to visible light remains a considerable challenge.We herein show the synthesis of ZnIn2S4/carbon quantum dot hybrid photocatalysts with flowerlike microspheres via a facile solvothermal method.The ZnIn2S4/carbon quantum dot flowerlike microspheres display enhanced photocatalytic and photoelectrochemical activity compared with that of pure ZnIn2S4.With a content of only 0.5 wt%carbon quantum dots,93%of Cr(VI)is reduced under visible‐light irradiation at 40 min.As a co‐catalyst,the carbon quantum dots improve the light absorption and lengthen the lifetime of charge carriers,consequently enhancing the photocatalytic and photoelectrochemical activity.
基金Project supported by the National Natural Science Foundation of China (NSFC21071107)Natural Science Foundation of Jiangsu Province (BK2008541)+4 种基金Key Laboratory for Oil-gas Storage and Transportation Engineering of Jiangsu Province (CY0901)Creative Project of Postgraduate of Jiangsu Province (CX10B-256Z)Key Laboratory for Environmental Function Materials of Suzhou (SZS201008)Industrial Surport Project of Suzhou (SYG201029)Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Porous CeO2 hollow microspheres were successfully prepared through a facile process by using the rape pollen as the biotemplate. Scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, the N2 adsorption and desorption, X-ray diffraction （XRD）, UV-vis diffuse reflectance spectra, and hydrogen temperature-programmed reduction （H2-TPR） were used for their characterization. The results showed that the obtained materials exhibited the same morphology as that of the pollen template, with a diameter of ca. 10 μm, and the surface was evenly covered with a special network-like structutre with mesh size of about 0.3 μm, and the Brunauer-Emmett-Teller （BET） surface area was measured to be 156 m2/g. The detailed property investigation inferred that the product exhibited better photocatalytic activity in acid fuchsine decolorization under daylight because of higher surface area, smaller crystallite size and higher oxygen capacity.
基金supported by the National Natural Science Foundation of China(21773031)the Natural Science Foundation of Fujian Province(2018J01686)the State Key Laboratory of Photocatalysis on Energy and Environment(SKLPEE-2017A01 and SKLPEE-2017B02)~~
文摘TiO2@Ni(OH)2 core-shell microspheres were synthesized by a facile strategy to obtain a perfect 3D flower-like nanostructure with well-arranged Ni(OH)2 nanoflakes on the surfaces of TiO2 microspheres;this arrangement led to a six-fold enhancement in photocatalytic hydrogen evolution. The unique p-n type heterostructure not only promotes the separation and transfer of photogenerated charge carriers significantly, but also offers more active sites for photocatalytic hydrogen production. A photocatalytic mechanism is proposed based on the results of electrochemical measurements and X-ray photoelectron spectroscopy.
基金financially supported by the National Natural Science Foundation of China(Nos.61271126,21547012 and 21305033)the Program for Innovative Research Team in University(No.IRT-1237)+2 种基金the Program for Science and Technology Project of Heilongjiang province(Nos.B201414 and B2015008)the Heilongjiang Educational Department(No.2013TD002,2011CJHB006,12531506)the Youth Foundation of Harbin(No.2015QQQXJ047)
文摘Hierarchically porous anatase Ti02 microspheres composited with carbonaceous species （TCS） have been successfully fabricated by a one-step template-free solvothermal method, combined with subsequent low temperature dried process. In this configuration, the TCS microspheres are constructed by the intercon- nected porous nanosheets, which are further assembled with abundant nanoparticles and carbonaceous species. Such composite microspheres possess a large specific surface area of 337 m2 g-l, uniform mesopores of 3.37 nm and high total pore volumes of 0.275 cm3 g-1. The materials exhibit the enhanced photocatalytic properties and stability for degradation of rhodamine B （RhB） under visible-light irradiation. The enhanced photocatalytic degradation performance may be ascribed to their abundant porous structure, large specific surface area and the unique assist-function of the carbonaceous species.
基金The authors are thankful to the National Natural Science Foundation of China(No.21978196,21676178,21706179)Shanxi Province Science Foundation for Youths(201801D211008).
文摘It is rather essential to design glorious system with high CO_(2) adsorption capacity and electron migration efficiency for improving selective and effective CO_(2) reduction into solar fuels.Here,as-synthesized phenolic resin spheres via suspension polymerization were carbonized and activated by water vapor to obtain activated carbon spheres(ACSs).Subsequently,Bi_(2)MoO_(6)/ACSs were prepared via hydrothermal-impregnated method.The systematical characterizations of samples,including XRD,XPS,SEM,EDX,DRS,BET,PL,CO_(2) adsorption isotherm,EIS and transient photocurrent,were analyzed.The results clearly demonstrated that Bi_(2)MoO_(6) with suitable oxidation reduction potentials and bandgap and ACSs with admirable CO_(2) adsorption and electrical conductivity not only enhanced separation efficiency of photoindued electron-hole pair,but also displayed as 1.8 times CO_(2) reduction activity to CO as single Bi_(2)MoO_(6) sample under Xe-lamp irradiation.Finally,a concerned photocatalytic CO_(2) reduction mechanism was proposed and investigated.Our findings should provide innovative guidance for designing a series of photocatalytic CO_(2) reduction materials with highly efficient and selective ability.
文摘TS-2 microspheres,consisting of intergrown primary nanocrystals,was prepared by controlling the synthetic parameters.The effects of the amount of quaternary ammonium cations as structure-directing agent,H2O/Si ratio,the presence of alcohol and the temperature were carefully investigated on the crystallization process.The high alkalinity was proved to be highly important for the preservation of the microsphere morphology initially formed,due to the unique intergrown stacking style.An alkali treatment with the aqueous solution of structure-directing agent,organic amine and ammonium salt and subsequent Na+ion-exchange were performed to enhance the catalytic activity of TS-2 microsphere in the cyclohexanone ammoximation reactions,with both the conversion and selectivity higher than 99%.In the continuous reaction,the TS-2 microspheres exhibited to be durable catalyst with potential application in industrial ammoximation processes.
基金Projects(21476269,21776319) supported by the National Natural Science Foundation of ChinaProject(2016TP1007) supported by Hunan Provincial Science and Technology Plan Project of China+2 种基金Project(2017J01569) supported by the Natural Science Foundation of Fujian Province,ChinaProject(201710533255) supported by National College Students’ Free Exploration Project of ChinaProject(2017zzts777) supported by Fundamental Research Funds for the Central Universities of Central South University,China
文摘A novel Bi2S3 microsphere was fabricated through one-pot urea-assisted solvothermal method.The synthesized Bi2S3 microsphere was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transformed infrared spectroscopy(FT-IR)and thermal gravimetric analysis and differential thermal analysis(DTA-TG).Subsequently,the photocatalytic performances of Bi2S3 microsphere were evaluated by photocatalytic degradation of methyl orange(MO)simulation solution under visible-light irradiation.The results show that,Bi2S3 microsphere could be used as a potential cost-efficient catalysis for eliminating of methyl orange from aqueous solutions,whose degradation rate could reach 91.07%within 180 min.Besides,a tentative photocatalytic reaction mechanism was discussed according to the energy band position.Therefore,this work indicated a simplistic approach for the fabrication of visible-light responsive Bi2S3 microsphere photocatalyst,which can be used as a valuable candidate in solar energy conversion and environment pollution treatment.
文摘Solar‐powered semiconductor photocatalysis is considered a powerful strategy for addressing environmental pollution and energy crisis.Nevertheless,the separation and transfer abilities of photogenerated photocatalysts remain unsatisfactory.Herein,dual Ti_(3)C_(2)nanosheets/Ag co‐catalysts synergistically decorated hierarchical flower‐like TiO_(2)microspheres for boosting photocatalytic H_(2)production were fabricated by electrostatic self‐assembly and subsequent photoreduction procedures.The optimal Ag/Ti_(3)C_(2)/TiO_(2)composite demonstrated an excellent photocatalytic H_(2)‐production rate of 1024.72μmol g^(−1)h^(−1)under simulated solar irradiation,achieving nearly 40,2.3,and 1.8 folds with respect to that obtained on pristine TiO2,optimized Ti_(3)C_(2)/TiO_(2)composite,and Ag/TiO_(2)composite,respectively.The considerably improved photocatalytic H_(2)‐production activity is associated with the synergistic effect of the hierarchical flower‐like structure of TiO2,excellent electrical conductivity of Ti_(3)C_(2),and surface plasmon resonance effect of Ag,which enhances the light absorption capacity and promotes the separation and transfer of photogenerated carriers.This study provides insight into the design of high‐efficiency photocatalysts with dual co‐catalysts for solar H_(2)production.
