The practical energy density of solid-state batteries remains limited,partly because of the lack of a general method to fabricate thin membranes for solid-state electrolytes with high ionic conductivity and low area-s...The practical energy density of solid-state batteries remains limited,partly because of the lack of a general method to fabricate thin membranes for solid-state electrolytes with high ionic conductivity and low area-specific resistance(ASR).Herein,we use an ultrahigh concentration of a ceramic ion conductor(Na_(3)SbS_(4))to build an ionconduction“highway”,and a polymer(polyethylene oxide,2 wt%)as a flexible host to prepare a polymer-inceramic ion-conducting membrane of approximately 40μm.Without the use of any salt(e.g.,NaPF_(6)),the resulting membrane exhibits a threefold increase in electronic ASR and a twofold decrease in ionic ASR compared with a pure ceramic counterpart.The activation energy for sodium-ion transport is only 190 meV in the membrane,similar to that in pure ceramic,suggesting ion transport predominantly occurs through a percolated network of ion-conducting ceramic particles.The salt-free design also provides an opportunity to suppress dendritic metal electrodeposits,according to a recently refined chemomechanical model of metal deposition.Our work suggests that salt is not always necessary in composite solid-state electrolytes,which broadens the choice of polymers to allow the optimization of other desired attributes,such as mechanical strength,chemical/electrochemical stability,and cost.展开更多
The liquid ion exchange method, solid salt melt method and dry-wet circulation method were used to prepare natural porous antimicrobial materials with natural minerals, such as zeolite, spilite, palygorskite and montm...The liquid ion exchange method, solid salt melt method and dry-wet circulation method were used to prepare natural porous antimicrobial materials with natural minerals, such as zeolite, spilite, palygorskite and montmorillonite, respectively. Atomic absorption spectrum and X-ray diffraction analysis were carried out to investigate the effects of Ag^＋ , Cu^2＋ and Zn^2＋ on antimicrobial abilities of natural porous minerals, and the effect of preparation method on ion exchange capacity of antimicrobial material, respectively. The results show that for the ion exchange capacity, clay mineral is higher than fibrous mineral, i.e. both zeolite and montmorillonite are higher; the antimicrobial ability of material with Ag^＋ is the bests the exchange capacities of materials with Cu^2＋ or Zn^2＋ are all higher, but the antimicrobial ability of Cu^2＋ is better than that of Zn^2＋ .展开更多
Carbon dots(CDs)have been widely adopted as optical materials because of their excellent luminescent properties.However,most of the reported synthetic methods are conducted in solvents,especially hydrothermal/solvothe...Carbon dots(CDs)have been widely adopted as optical materials because of their excellent luminescent properties.However,most of the reported synthetic methods are conducted in solvents,especially hydrothermal/solvothermal reactions,leading to intractable problems such as toxic and flammable solvents,complex and inseparable by-products,and dangerously high pressures and temperatures.Solid-phase synthesis of CDs in air is an effective solution to overcome the above issues,but solid reactions always result in uncontrolled growth and agglomeration of nanoparticles.In this study,some inorganic salts are selected as catalysts for synthesizing CDs in solid states and air,which also play as dispersants to hinder CDs aggregation.In the meantime,some aromatic derivatives containing hydroxyl and amino groups are chosen as carbon sources,ground with the optimized catalyst,and then heated together in air.The production yields are affected by the reaction time and reactant ratio,while the graphitization degrees of the CDs are determined by the reaction temperature.The IG/ID value of their Raman spectra increases from 0.59 to 0.85,and the particle size decreases from 2.5 to 1.4 nm when the synthesis temperature is increased from 200 to 280℃.The as-prepared CDs show emission peaks ranging from 366 to 606 nm,with the photoluminescence(PL)quantum yield up to 53%.Their emission color variation mainly results from different carbon sources,which can be ascribed to the differences in the element composition,functional groups,and graphitic nitrogen content of these CDs.By dispersing CDs of different concentrations into polyvinyl alcohol(PVA)and combining them with blue LEDs,cold,standard,and warm white light emitting devices(WLEDs)are prepared,with a color rendering index(CRI)up to 84.Since the as-prepared CDs have antioxidant ability at high temperature,the as-prepared WLEDs have long lifespans,remaining the effective white luminescence after 72 h continuous work.展开更多
Through orthogonal experiment, a new type of LiClO4-LiNO3-LiBr eutectic salt with optimum mole ratio of n（LiClO4）∶n（LiNO3）∶n（LiBr）=1.6∶3.8∶1.0 was prepared. The poly（lithium acrylate-acrylonitrile）/LiClO4-...Through orthogonal experiment, a new type of LiClO4-LiNO3-LiBr eutectic salt with optimum mole ratio of n（LiClO4）∶n（LiNO3）∶n（LiBr）=1.6∶3.8∶1.0 was prepared. The poly（lithium acrylate-acrylonitrile）/LiClO4-LiNO3-LiBr solid polymer electrolytes were prepared with poly（lithium acrylate-acrylonitrile） and （LiClO4-LiNO3-LiBr） eutectic salts. The effect of LiClO4-LiNO3-LiBr eutectic salts content on the conductivity of solid polymer electrolytes was studied by alternating current impedance method, and the structures of eutectic salts and solid polymer electrolytes were characterized by differential thermal analysis, infrared spectroscopy and X-ray diffractometry. The results show that the room temperature conductivity of LiClO4-LiNO3-LiBr eutectic salts reaches (3.11×10-4 S·cm-1.) The poly（lithium acrylate-acrylonitrile）/LiClO4-LiNO3-LiBr solid polymer electrolytes possess the highest room temperature conductivity at 70% LiClO4-LiNO3-LiBr eutectic salts content, and exhibit lower glass transition temperature of 75 ℃ compared with that of poly（lithium acrylate-acrylonitrile） of 105 ℃. A complex may be formed in the solid polymer electrolytes from the differential thermal analysis and infrared spectroscopy analysis. X-ray diffraction results show that the poly（lithium acrylate-acrylonitrile） can suppress the crystallization of eutectic salts in this system.展开更多
Solid oxide membrane-assisted electrolytic reduction of solid Cr_(2)O_(3) to Cr in molten CaCl_(2) was performed using a sintered porous Cr_(2)O_(3) cathode paired with an yttria-stabilized zirconia(YSZ)tube anode con...Solid oxide membrane-assisted electrolytic reduction of solid Cr_(2)O_(3) to Cr in molten CaCl_(2) was performed using a sintered porous Cr_(2)O_(3) cathode paired with an yttria-stabilized zirconia(YSZ)tube anode containing carbon-saturated liquid copper alloy.Analyses of the reduction mechanism,ion migration behavior,and effects of cathode pellet porosity and particle size on the electrolysis products and reduction rate revealed that the cathode microstructure and electrolytic conditions were key factors influencing the electrolysis process.Optimal results were obtained when the cathode was characterized by high porosity and a small particle size because this combination of features contributed to ion migration.Good electrochemical activation was observed when cathode pellets prepared by 4 MPa molding followed by 2 h of sintering at 1150℃ were applied.The electrode reduction process(Cr^(3+)→Cr^(2+)→Cr)was promoted by high electrode voltages,and Cr metal was efficiently formed.The proposed method appears to be well suited for electrolytic Cr production because it does not require expensive pre-electrolysis techniques or generate harmful by-products.展开更多
A novel crystal [（CH3O）2CO]3Li2[C2BF2O4]2 was synthesized and fully characterized by FT-IR and single-crystal X-ray diffraction analysis. It crystallizes in monoclinic system, P2Jn space group, with a = 8.1749（2）,...A novel crystal [（CH3O）2CO]3Li2[C2BF2O4]2 was synthesized and fully characterized by FT-IR and single-crystal X-ray diffraction analysis. It crystallizes in monoclinic system, P2Jn space group, with a = 8.1749（2）, b = 10.7449（2）, c = 12.8665（3） A, βl = 94.654（2）°, V= 1126.45（4） A3, Z = 2, Dc = 1.644 g/cm, F（000） = 568, p = 1.498 mm^-1, Mr= 557.77 g/mol, the final R = 0.0334 and wR = 0.0903. The structure analysis revealed that each Li atom is three-coordinated and adopts 1.5 O atoms of two different dimethyl carbonates and one O atom of C2BF2O4-. Thermal stability and infrared spectra analysis were studied and discussed.展开更多
Pr^（3＋）-activated barium tungsto-molybdate solid solution phosphor Ba（Mo_（1-z）W_z）O_4：Pr^（3＋）is successfully fabricated via a facile molten-salt approach. The as-synthesized microcrystal is of truncated oct...Pr^（3＋）-activated barium tungsto-molybdate solid solution phosphor Ba（Mo_（1-z）W_z）O_4：Pr^（3＋）is successfully fabricated via a facile molten-salt approach. The as-synthesized microcrystal is of truncated octahedron and exhibits deep-red-emitting upon blue light excitation. Powder x-ray diffraction and Raman spectroscopy techniques are utilized to investigate the formation of solid solution phosphor. The luminescence behaviors depend on the resulting composition of the microcrystals with fixed Pr^（3＋）-doping concentration, while the host lattices remain in a scheelite structure. The forming solid solution via the substitution of [WO_4] for [MoO_4] can significantly enhance its luminescence, which may be due to the fact that Ba（Mo_（1-z）W_z）O_4：Pr^（3＋）owns well-defined facets and uniform morphologies. Owing to its properties of high phase purity,well-defined facets, highly uniform morphologies, exceptional chemical and thermal stabilities, and stronger emission intensity, the resulting solid solution phosphor is expected to find potential applications in phosphor-converted white lightemitting diodes（LEDs）.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51902201,51527801).The authors would also like to thank Dr.Chunjie Cao from Carl Zeiss(Shanghai)Co.,Ltd.for the XRM figure processing,and Ms.Yirong Gao for constructive suggestions and comments regarding the manuscript.
文摘The practical energy density of solid-state batteries remains limited,partly because of the lack of a general method to fabricate thin membranes for solid-state electrolytes with high ionic conductivity and low area-specific resistance(ASR).Herein,we use an ultrahigh concentration of a ceramic ion conductor(Na_(3)SbS_(4))to build an ionconduction“highway”,and a polymer(polyethylene oxide,2 wt%)as a flexible host to prepare a polymer-inceramic ion-conducting membrane of approximately 40μm.Without the use of any salt(e.g.,NaPF_(6)),the resulting membrane exhibits a threefold increase in electronic ASR and a twofold decrease in ionic ASR compared with a pure ceramic counterpart.The activation energy for sodium-ion transport is only 190 meV in the membrane,similar to that in pure ceramic,suggesting ion transport predominantly occurs through a percolated network of ion-conducting ceramic particles.The salt-free design also provides an opportunity to suppress dendritic metal electrodeposits,according to a recently refined chemomechanical model of metal deposition.Our work suggests that salt is not always necessary in composite solid-state electrolytes,which broadens the choice of polymers to allow the optimization of other desired attributes,such as mechanical strength,chemical/electrochemical stability,and cost.
文摘The liquid ion exchange method, solid salt melt method and dry-wet circulation method were used to prepare natural porous antimicrobial materials with natural minerals, such as zeolite, spilite, palygorskite and montmorillonite, respectively. Atomic absorption spectrum and X-ray diffraction analysis were carried out to investigate the effects of Ag^＋ , Cu^2＋ and Zn^2＋ on antimicrobial abilities of natural porous minerals, and the effect of preparation method on ion exchange capacity of antimicrobial material, respectively. The results show that for the ion exchange capacity, clay mineral is higher than fibrous mineral, i.e. both zeolite and montmorillonite are higher; the antimicrobial ability of material with Ag^＋ is the bests the exchange capacities of materials with Cu^2＋ or Zn^2＋ are all higher, but the antimicrobial ability of Cu^2＋ is better than that of Zn^2＋ .
基金supported by the National Natural Science Foundation of China(No.21975048)the Shanghai Science and Technology Committee(No.19DZ2270100).
文摘Carbon dots(CDs)have been widely adopted as optical materials because of their excellent luminescent properties.However,most of the reported synthetic methods are conducted in solvents,especially hydrothermal/solvothermal reactions,leading to intractable problems such as toxic and flammable solvents,complex and inseparable by-products,and dangerously high pressures and temperatures.Solid-phase synthesis of CDs in air is an effective solution to overcome the above issues,but solid reactions always result in uncontrolled growth and agglomeration of nanoparticles.In this study,some inorganic salts are selected as catalysts for synthesizing CDs in solid states and air,which also play as dispersants to hinder CDs aggregation.In the meantime,some aromatic derivatives containing hydroxyl and amino groups are chosen as carbon sources,ground with the optimized catalyst,and then heated together in air.The production yields are affected by the reaction time and reactant ratio,while the graphitization degrees of the CDs are determined by the reaction temperature.The IG/ID value of their Raman spectra increases from 0.59 to 0.85,and the particle size decreases from 2.5 to 1.4 nm when the synthesis temperature is increased from 200 to 280℃.The as-prepared CDs show emission peaks ranging from 366 to 606 nm,with the photoluminescence(PL)quantum yield up to 53%.Their emission color variation mainly results from different carbon sources,which can be ascribed to the differences in the element composition,functional groups,and graphitic nitrogen content of these CDs.By dispersing CDs of different concentrations into polyvinyl alcohol(PVA)and combining them with blue LEDs,cold,standard,and warm white light emitting devices(WLEDs)are prepared,with a color rendering index(CRI)up to 84.Since the as-prepared CDs have antioxidant ability at high temperature,the as-prepared WLEDs have long lifespans,remaining the effective white luminescence after 72 h continuous work.
文摘Through orthogonal experiment, a new type of LiClO4-LiNO3-LiBr eutectic salt with optimum mole ratio of n（LiClO4）∶n（LiNO3）∶n（LiBr）=1.6∶3.8∶1.0 was prepared. The poly（lithium acrylate-acrylonitrile）/LiClO4-LiNO3-LiBr solid polymer electrolytes were prepared with poly（lithium acrylate-acrylonitrile） and （LiClO4-LiNO3-LiBr） eutectic salts. The effect of LiClO4-LiNO3-LiBr eutectic salts content on the conductivity of solid polymer electrolytes was studied by alternating current impedance method, and the structures of eutectic salts and solid polymer electrolytes were characterized by differential thermal analysis, infrared spectroscopy and X-ray diffractometry. The results show that the room temperature conductivity of LiClO4-LiNO3-LiBr eutectic salts reaches (3.11×10-4 S·cm-1.) The poly（lithium acrylate-acrylonitrile）/LiClO4-LiNO3-LiBr solid polymer electrolytes possess the highest room temperature conductivity at 70% LiClO4-LiNO3-LiBr eutectic salts content, and exhibit lower glass transition temperature of 75 ℃ compared with that of poly（lithium acrylate-acrylonitrile） of 105 ℃. A complex may be formed in the solid polymer electrolytes from the differential thermal analysis and infrared spectroscopy analysis. X-ray diffraction results show that the poly（lithium acrylate-acrylonitrile） can suppress the crystallization of eutectic salts in this system.
基金the National Natural Science Foundation of China(Nos.51664005,51774102,U1812402,and 51804088)Talents of Guizhou Science and Technology Cooperation Platform(Platform Talent[2017]5626 and KY(2015)334)。
文摘Solid oxide membrane-assisted electrolytic reduction of solid Cr_(2)O_(3) to Cr in molten CaCl_(2) was performed using a sintered porous Cr_(2)O_(3) cathode paired with an yttria-stabilized zirconia(YSZ)tube anode containing carbon-saturated liquid copper alloy.Analyses of the reduction mechanism,ion migration behavior,and effects of cathode pellet porosity and particle size on the electrolysis products and reduction rate revealed that the cathode microstructure and electrolytic conditions were key factors influencing the electrolysis process.Optimal results were obtained when the cathode was characterized by high porosity and a small particle size because this combination of features contributed to ion migration.Good electrochemical activation was observed when cathode pellets prepared by 4 MPa molding followed by 2 h of sintering at 1150℃ were applied.The electrode reduction process(Cr^(3+)→Cr^(2+)→Cr)was promoted by high electrode voltages,and Cr metal was efficiently formed.The proposed method appears to be well suited for electrolytic Cr production because it does not require expensive pre-electrolysis techniques or generate harmful by-products.
基金supported by the National Natural Science Foundation of China(210011111)
文摘A novel crystal [（CH3O）2CO]3Li2[C2BF2O4]2 was synthesized and fully characterized by FT-IR and single-crystal X-ray diffraction analysis. It crystallizes in monoclinic system, P2Jn space group, with a = 8.1749（2）, b = 10.7449（2）, c = 12.8665（3） A, βl = 94.654（2）°, V= 1126.45（4） A3, Z = 2, Dc = 1.644 g/cm, F（000） = 568, p = 1.498 mm^-1, Mr= 557.77 g/mol, the final R = 0.0334 and wR = 0.0903. The structure analysis revealed that each Li atom is three-coordinated and adopts 1.5 O atoms of two different dimethyl carbonates and one O atom of C2BF2O4-. Thermal stability and infrared spectra analysis were studied and discussed.
基金Project supported by the Construction Fund for Science and Technology Innovation Group from Jiangsu University of Technology,Chinathe Key Laboratory of Atmospheric Environment Monitoring and Pollution Control,China(Grant No.KHK1409)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions,Chinathe National Natural Science Foundation of China(Grant No.21373103)
文摘Pr^（3＋）-activated barium tungsto-molybdate solid solution phosphor Ba（Mo_（1-z）W_z）O_4：Pr^（3＋）is successfully fabricated via a facile molten-salt approach. The as-synthesized microcrystal is of truncated octahedron and exhibits deep-red-emitting upon blue light excitation. Powder x-ray diffraction and Raman spectroscopy techniques are utilized to investigate the formation of solid solution phosphor. The luminescence behaviors depend on the resulting composition of the microcrystals with fixed Pr^（3＋）-doping concentration, while the host lattices remain in a scheelite structure. The forming solid solution via the substitution of [WO_4] for [MoO_4] can significantly enhance its luminescence, which may be due to the fact that Ba（Mo_（1-z）W_z）O_4：Pr^（3＋）owns well-defined facets and uniform morphologies. Owing to its properties of high phase purity,well-defined facets, highly uniform morphologies, exceptional chemical and thermal stabilities, and stronger emission intensity, the resulting solid solution phosphor is expected to find potential applications in phosphor-converted white lightemitting diodes（LEDs）.
