According to the oxidation intensity of ore-hosting sandstone, the interlayer oxidation zone of the Shihongtan sandstone-type uranium deposit in the Turpan-Hami basin can be divided into 4 geochemical subzones, namely...According to the oxidation intensity of ore-hosting sandstone, the interlayer oxidation zone of the Shihongtan sandstone-type uranium deposit in the Turpan-Hami basin can be divided into 4 geochemical subzones, namely, intenselyoxidized, weakly-oxidized, redox and unoxidized primary subzones. The elemental geochemical characteristics of the four subzones have been studied in detail, and the results show that U, together with other elements such as Re, Mo, Se, Sr, S, REE, Corganic etc., is enriched in the redox subzone. Re and U have similar geochemical properties in the reductionoxidation process. The geochemical properties of Mo and Se are similar to those of U in the reduction condition, but different from those of U in the oxidation condition. It is proposed that the ore-hosting layers can provide a curtain mount of uranium for uranium mineralization.展开更多
The high-energy lithium/sulfur(Li/S) battery has become a very popular topic of research in recent years due to its high theoretical capacity of 1672 m Ah/g. However, the polysulfide shuttle effect remains of great co...The high-energy lithium/sulfur(Li/S) battery has become a very popular topic of research in recent years due to its high theoretical capacity of 1672 m Ah/g. However, the polysulfide shuttle effect remains of great concern with a great number of publications dedicated to its mitigation. In this contribution, a three-dimensional(3D) reduced graphene oxide/activated carbon(RGO/AC) film, synthesized by a simple hydrothermal method and convenient mechanical pressing, is sandwiched between the separator and the sulfur-based cathode, acting as a functional interlayer to capture and trap polysulfide species. Consequently, the Li/S cell with this interlayer shows an impressive initial discharge capacity of 1078 m Ah/g and a reversible capacity of 655 m Ah/g even after 100 cycles. The RGO/AC interlayer impedes the movement of polysulfide while providing unimpeded channels for lithium ion mass transfer. Therefore, the RGO/AC interlayer with a well-designed structure represents strong potential for high-performance Li/S batteries.展开更多
Graphene oxide (GO) contains numerous functional groups that facilitate the intercalation of polar solvents. The properties and applications of GO are closely related to its interlayer spacing. We report on the chan...Graphene oxide (GO) contains numerous functional groups that facilitate the intercalation of polar solvents. The properties and applications of GO are closely related to its interlayer spacing. We report on the changes in the interlayer spacing of GO after the adsorption of water molecules and the polar organic solvents C2H602 (EG), C3HTNO (DMF), C5H9NO (NMP). Experiments were conducted to investigate the variations in the functional groups and structure of GO after solvent adsorp-tion, and they play a vital role in modeling and verifying the results of molecular dynamics simulation. The most stable GO structures are obtained through molecular dynamics simulation. The expansion of the interlayer spacing of GO after the adsorption of monolayer solvent molecules corresponds to the minimum three-dimensional size of the solvent molecules. The spatial arrangement of solvent molecules also contributes to the changes in interlayer spacing. Most adsorbed molecules are oriented parallel to the carbon plane of GO. However, as additional molecules are adsorbed into the interlaminations of GO, the adsorbed molecules are oriented perpendicular to the carbon plane of GO, and a large space forms between two GO interlayers. In addition, the role of large molecules in increasing interlayer spacing becomes more crucial than that of water molecules in the adsorption of binary solvent systems by GO.展开更多
A composite interlayer comprised of gadolinia doped ceria(GDC) and Co/Fe oxide was prepared and investigated for solid oxide electrolysis cell with yttrium stabilized zirconia(YSZ) electrolyte and LaSrCoFeO(LSCF...A composite interlayer comprised of gadolinia doped ceria(GDC) and Co/Fe oxide was prepared and investigated for solid oxide electrolysis cell with yttrium stabilized zirconia(YSZ) electrolyte and LaSrCoFeO(LSCF) anode. The interlayer was constructed of a base layer of GDC and a top layer of discrete CoO/FeCoOparticles. The presence of the GDC layer drastically alleviated the undesired reactions between LSCF and YSZ, and the presence of Co/Fe oxide led to further performance improvement. At 800 °C and 45% humidity, the cell with 70% Co/Fe-GDC interlayer achieved 0.98 A/cmat 1.18 V, 14% higher than the cell without Co/Fe oxide. Electrochemical impedance spectroscopy(EIS) revealed that with higher Co/Fe content, both the ohmic resistance and the polarization resistance of the cell were reduced. It is suggested that Co/Fe oxide can react with the Sr species segregated from LSCF and Sr(Co,Fe)O, a compound with high catalytic activity and electronic conductivity. The Sr-capturing ability of Co/Fe oxide in combination with the Sr-blocking ability of GDC layer can effectively suppress the undesired reaction between LSCF and YSZ, and consequently improve the cell performance.展开更多
Vanadium oxides,par-ticularly hydrated forms like V_(2)O_(5)·nH_(2)O(VOH),stand out as promising cathode candidates for aqueous zinc ion batteries due to their adjustable layered structure,unique electronic chara...Vanadium oxides,par-ticularly hydrated forms like V_(2)O_(5)·nH_(2)O(VOH),stand out as promising cathode candidates for aqueous zinc ion batteries due to their adjustable layered structure,unique electronic characteristics,and high theoretical capacities.However,challenges such as vanadium dissolution,sluggish Zn^(2+)diffusion kinetics,and low operating voltage still hinder their direct application.In this study,we present a novel vanadium oxide([C_(6)H_(6)N(CH_(3))_(3)]_(1.08)V_(8)O_(20)·0.06H_(2)O,TMPA-VOH),developed by pre-inserting trimethylphenylammonium(TMPA+)cations into VOH.The incorporation of weakly polarized organic cations capitalizes on both ionic pre-intercalation and molecular pre-intercalation effects,resulting in a phase and morphology transition,an expansion of the interlayer distance,extrusion of weakly bonded interlayer water,and a substantial increase in V^(4+)content.These modifications synergistically reduce the electrostatic interactions between Zn^(2+)and the V-O lattice,enhancing structural stability and reaction kinetics during cycling.As a result,TMPA-VOH achieves an elevated open circuit voltage and operation voltage,exhibits a large specific capacity(451 mAh g^(-1)at 0.1 A g^(-1))coupled with high energy efficiency(89%),the significantly-reduced battery polarization,and outstanding rate capability and cycling stability.The concept introduced in this study holds great promise for the development of high-performance oxide-based energy storage materials.展开更多
Low temperature prepared(La;Sr;);MnO;-δ-Y;Zr;O;(LSM-YSZ) nano-composite cathode has high three-phase boundary(TPB) density and shows higher oxygen reduction reaction(ORR) activity than traditional LSM-YSZ catho...Low temperature prepared(La;Sr;);MnO;-δ-Y;Zr;O;(LSM-YSZ) nano-composite cathode has high three-phase boundary(TPB) density and shows higher oxygen reduction reaction(ORR) activity than traditional LSM-YSZ cathode at reduced temperatures. But the weak connection between cathode and electrolyte due to low sintering temperature restrains the performance of LSM-YSZ nano-composite cathode. A YSZ interlayer, consisted of nanoparticles smaller than 10 nm, is introduced by spinning coating hydrolyzed YSZ sol solution on electrolyte and sintering at 800 °C. The thickness of the interlayer is about 150 nm. The YSZ interlayer intimately adheres to the electrolyte and shows obvious agglomeration with LSM-YSZ nano-composite cathode. The power densities of the cell with interlayer are 0.83, 0.46 and 0.21 W/cm;under 0.7 V at 800, 700 and 600 °C, respectively, which are 36%, 48% and 50% improved than that of original cell. The interlayer introduction slightly increases the ohmic resistance but significantly decreases the polarization resistance. The depressed high frequency arcs of impedance spectra suggest that the oxygen incorporation kinetics are enhanced at the boundary of YSZ interlayer and LSM-YSZ nanocomposite cathode, contributing to improved electrochemical performance of the cell with interlayer.展开更多
We report a strong antiferromagnetic(AFM) interlayer coupling in ferromagnetic La_(0.67)Sr_(0.33)MnO_3/SrRuO_3(LSMO/SRO) superlattices grown on(111)-oriented SrTiO_3 substrate. Unlike the(001) superlattices for which ...We report a strong antiferromagnetic(AFM) interlayer coupling in ferromagnetic La_(0.67)Sr_(0.33)MnO_3/SrRuO_3(LSMO/SRO) superlattices grown on(111)-oriented SrTiO_3 substrate. Unlike the(001) superlattices for which the spin alignment between LSMO and SRO is antiparallel in the in-plane direction and parallel in the out-of-plane direction, the antiparallel alignment is observed along both the in-plane and out-of-plane directions in the present sample. The low temperature hysteresis loop demonstrates two-step magnetic processes, indicating the coexistence of magnetically soft and hard components. Moreover, an inverted hysteresis loop was observed. Exchange bias tuned by the temperature and cooling field was also investigated, and positive as well as negative exchange bias was observed at the same temperature with the variation of the cooling field. A very large exchange field(H_(EB)) was observed and both magnitude and sign of the H_(EB)depend on the cooling field, which can be attributed to an interplay of Zeeman energy and AFM coupling energy at the interfaces. The present work shows the great potential of tuning a spin texture through interfacial engineering for the complex oxides whose spin state is jointly determined by strongly competing mechanisms.展开更多
The paper reports that Hfrio dielectric is deposited by reactive co-sputtering of Hf and Ti targets in an Ar/O2 ambience, followed by an annealing in different gas ambiences of N2, NO and NH3 at 600℃ for 2 min. Capac...The paper reports that Hfrio dielectric is deposited by reactive co-sputtering of Hf and Ti targets in an Ar/O2 ambience, followed by an annealing in different gas ambiences of N2, NO and NH3 at 600℃ for 2 min. Capacitancevoltage and gate-leakage properties are characterized and compared. The results indicate that the NO-annealed sample exhibits the lowest interface-state and dielectric-charge densities and best device reliability. This is attributed to the fact that nitridation can create strong Si≡N bonds to passivate dangling Si bonds and replace strained Si-O bonds, thus the sample forms a hardened dielectric/Si interface with high reliability.展开更多
Vanadium pentoxide(V_(2)O_(5))with a layered structure is of great interest in the field of electrochromic(EC)due to its abundance of color variations.However,there are still a series of problems such as slow ion diff...Vanadium pentoxide(V_(2)O_(5))with a layered structure is of great interest in the field of electrochromic(EC)due to its abundance of color variations.However,there are still a series of problems such as slow ion diffusion,poor electronic conductivity and cyclic stability in the reaction process.Herein,we successfully prepared a stable and fast multi-color electrochromic material V_(2)O_(5)-PEDOT by a simple“one-pot”method.The layer space of V_(2)O_(5)could be tuned by 3,4-ethylenedioxythiophene(named V_(2)O_(5)-PEDOT)during the dissolution and recrystallization of vanadium oxide.The expanded layer spacing facilitates rapid ion insertion and extraction.PEDOT serves as an internal conductive pillar to improve the overall conductivity of the material.The obtained intercrossing structure of the nanobelts shortens the ion diffusion distance and ensures electrolyte penetration.The V_(2)O_(5)-PEDOT exhibits the fast response time(1.1 s for coloration and 3.5 s for bleaching at 422 nm),high optical contrast(ΔT=45%at 422 nm andΔT=35.2%at 1000 nm),great coloration efficiency(CE=97.1 cm2/C),and high cyclic stability(86%preserved after 3000 cycles).The electrochromic devices(ECD)were successfully assembled by using V_(2)O_(5)-PEDOT films as ion storage layers and electrochromic layers,demonstrating remarkable performance.展开更多
Copper intercalated birnessite MnO_(2)(δ-MnO_(2))with weak crystallinity and high specific surface area(421 m^(2)/g)was synthesized by a one-pot redox method and investigated for low-temperature CO oxidation.The mola...Copper intercalated birnessite MnO_(2)(δ-MnO_(2))with weak crystallinity and high specific surface area(421 m^(2)/g)was synthesized by a one-pot redox method and investigated for low-temperature CO oxidation.The molar ratio of Cu/Mn was as high as 0.37,which greatly weakened the Mn-O bond and created a lot of low-temperature active oxygen species.In situ DRIFTS revealed strong bonding of copper ions with CO.As-synthesized MnO_(2)-150Cu achieved 100%conversion of 250 ppm CO in normal air(3.1 ppm H_(2)O)even at−10°C under the weight-hourly space velocity(WHSV)of 150 L/(g·h).In addition,it showed high oxygen storage capacity to oxidize CO in inert atmosphere.Though the concurrent moisture in air significantly inhibited CO adsorption and its conversion at ambient temperature,MnO_(2)-150Cu could stably convert CO in 1.3%moisture air at 70°C owing to its great low-temperature activity and reduced competitive adsorption of water with increased temperature.This study discovers the excellent low-temperature activity of weakly crystallized δ-MnO_(2) induced by high content intercalated copper ions.展开更多
The oxide layer on the surface has always been a key obstacle to achieving the diffusion bonding of Al alloys.It is a challenge for performing diffusion bonding without removing oxide layers.Herein,diffusion bonding o...The oxide layer on the surface has always been a key obstacle to achieving the diffusion bonding of Al alloys.It is a challenge for performing diffusion bonding without removing oxide layers.Herein,diffusion bonding of Al alloy retaining continuous oxide layers was successfully achieved in the air by a low-temperature and low-pressure diffusion bonding mothed using a Zn interlayer.During the bonding processes,conducted at 360℃ and 3 MPa,Zn diffused into Al through cracks of thin oxide layers to form the joint composed Al/(diffusion layer)/(oxide layer)/(Zn)/(oxide layer)/(diffusion layer)/Al.The diffusion layers were composed of Zn-Al eutectoid,and the oxide layer included nanocrystals and amorphous Al_(2)O_(3).The shear strength of joints containing continuous oxide layers was about 30 MPa.Interestingly,the migration behavior toward the joint center of the interfacial oxide layers was observed with consuming of the Zn interlayer.The cracking phenomenon,the“subcutaneous diffusion”and the migration behavior of oxide layers were verified and analyzed by the diffusion bonding of anodized 6063Al-6063Al.Subsequently,the dynamic migration mechanism of oxide layers with elements diffusion and bonding interface strengths were discussed in detail.The ability to join Al alloys in the air at low temperatures and low pressure suggests a highly practical and economic method for diffusion bonding.展开更多
The Turfan-Hami basin is the key area for the exploration of sandstone uranium deposits of the leachable interlayered oxidation zone type. The aim of this study is to shed light on the development characteristics of t...The Turfan-Hami basin is the key area for the exploration of sandstone uranium deposits of the leachable interlayered oxidation zone type. The aim of this study is to shed light on the development characteristics of this type of uranium deposits and provide new clues to further exploration. Detailed study led to the following conclusions: (1) uranium orebodies are hosted mainly in the lower Middle Jurassic Xishanyao Formation and the lower Lower Jurassic Badaowan Formation; (2) the formation of uranium orebodies is closely related to organic matter; (3) the front of the interlayered oxidation zone is snake-shaped in plane and imbricated in the section; the more the interlayered oxidation zone and zonation are developed, the better the uranium mineralization will be; according to lithological and geochemical characteristics, the oxidation zone, the oxidation-reduction transitional zone and the reduction zone can be distin-guished; (4) the development of interlayered oxidation zone is controlled by geological structure, underground water, sandstone permeability and other factors; (5) sandstone uranium orebodies hosted in the interlayered oxidation zone are very complicated in spatial distribution, of which some are rolled and plated in shape and some are highly variable in shape.展开更多
This paper reveals the physicochemical properties such as component, formulation, genesis, tem- perature, pH, Eh, salinity and pressure of all main alteration fluid of interlayer oxidation zone sand- stone-type uraniu...This paper reveals the physicochemical properties such as component, formulation, genesis, tem- perature, pH, Eh, salinity and pressure of all main alteration fluid of interlayer oxidation zone sand- stone-type uranium deposits after studying the geologic process and geochemistry of internal typical sandstone-type uranium deposits such as Shihongtan deposit in the Turpan-Hami basin, 512 deposit in the Yili basin, Dongsheng deposit in the Ordos basin. The composition of fluid can be divided into two parts based on the analysis of inclusion: one can be affirmed as atmospheric water with ordinary temperature epigenesist according to the character of hydrogen and oxygen isotope of inclusion, the other is natural gas containing gaseous hydrocarbon like CH4, and CO2 as well as a little H2S, CO, H2, N2 and so on, it always contains a small quantity of hydrocarbon liquid in petroliferous basins. The fluid property of oxidation alteration zone is always oxidation alkaline, and neutrality or weak acid-weak alkaline and reducibility during the metallizing process, but at secondary reduction or deoxidization zone it becomes strong reduction alkaline. Oxygenic groundwater in the fluid is the activate and mig- ratory medium of uranium element, but the gaseous hydrocarbon like CH4 as well as H2, H2S, CO from natural gas is the important sedimentary reducer of uranium mineral; the transformation of pH,Eh in fluid environment is the main reason for the formation of uranium metallization.展开更多
Chemical oxidation and metal intercalation of natural graphite was utilized to increase the capacity and enhance the cycle property of graphite anodes in lithium ion batteries.
The large energy barrier in hole extraction still remains a great challenge in developing hole transporting layer (HTL) materials for organic solar cells (OSCs).Thus,solution-processed HTL materials with excellent hol...The large energy barrier in hole extraction still remains a great challenge in developing hole transporting layer (HTL) materials for organic solar cells (OSCs).Thus,solution-processed HTL materials with excellent hole collection ability and good compatibility with large-area processing technique are strongly desired for OSCs.Herein,we developed a cost-effective and solution-processed MoO_(3)HTL for efficient OSCs.By adding a small amount of glucose as reducing reagent into the ammonium molybdate precursor solution,a deeply n-doped MoO_(3),namely G:Mo,was prepared through the sol–gel method.Compared to pristine MoO_(3),the conductivity of G:Mo was enhanced by two orders of magnitude,which greatly improved the hole collection ability of the HTL.OSCs with G:Mo can exhibit comparable PCE to the PEDOT:PSS device.Using PBDB-TF:BTP-eC9 as the active layer,a PCE of 17.1%is obtained for the device,which is the highest PCE value for OSC using a solution-processed MoO_(3)HTL.More importantly,G:Mo is well compatible with the blade-coating processing.The OSC using a blade-coated G:Mo showed almost no PCE loss as compared to the device with spin-coated G:Mo HTL.The results from this work indicate that G:Mo is a promising HTL material for the practical production of OSCs.展开更多
文摘According to the oxidation intensity of ore-hosting sandstone, the interlayer oxidation zone of the Shihongtan sandstone-type uranium deposit in the Turpan-Hami basin can be divided into 4 geochemical subzones, namely, intenselyoxidized, weakly-oxidized, redox and unoxidized primary subzones. The elemental geochemical characteristics of the four subzones have been studied in detail, and the results show that U, together with other elements such as Re, Mo, Se, Sr, S, REE, Corganic etc., is enriched in the redox subzone. Re and U have similar geochemical properties in the reductionoxidation process. The geochemical properties of Mo and Se are similar to those of U in the reduction condition, but different from those of U in the oxidation condition. It is proposed that the ore-hosting layers can provide a curtain mount of uranium for uranium mineralization.
基金financial support from the National Natural Science Foundation of China(grant no.21406052the Program for the Outstanding Young Talents of Hebei Province(grant no.BJ2014010)the Scientific Research Foundation for Selected Overseas Chinese Scholars,Ministry of Human Resources and Social Security of China(grant no.CG2015003002)
文摘The high-energy lithium/sulfur(Li/S) battery has become a very popular topic of research in recent years due to its high theoretical capacity of 1672 m Ah/g. However, the polysulfide shuttle effect remains of great concern with a great number of publications dedicated to its mitigation. In this contribution, a three-dimensional(3D) reduced graphene oxide/activated carbon(RGO/AC) film, synthesized by a simple hydrothermal method and convenient mechanical pressing, is sandwiched between the separator and the sulfur-based cathode, acting as a functional interlayer to capture and trap polysulfide species. Consequently, the Li/S cell with this interlayer shows an impressive initial discharge capacity of 1078 m Ah/g and a reversible capacity of 655 m Ah/g even after 100 cycles. The RGO/AC interlayer impedes the movement of polysulfide while providing unimpeded channels for lithium ion mass transfer. Therefore, the RGO/AC interlayer with a well-designed structure represents strong potential for high-performance Li/S batteries.
基金supported by the National Natural Science Foundation of China(No.21576188)
文摘Graphene oxide (GO) contains numerous functional groups that facilitate the intercalation of polar solvents. The properties and applications of GO are closely related to its interlayer spacing. We report on the changes in the interlayer spacing of GO after the adsorption of water molecules and the polar organic solvents C2H602 (EG), C3HTNO (DMF), C5H9NO (NMP). Experiments were conducted to investigate the variations in the functional groups and structure of GO after solvent adsorp-tion, and they play a vital role in modeling and verifying the results of molecular dynamics simulation. The most stable GO structures are obtained through molecular dynamics simulation. The expansion of the interlayer spacing of GO after the adsorption of monolayer solvent molecules corresponds to the minimum three-dimensional size of the solvent molecules. The spatial arrangement of solvent molecules also contributes to the changes in interlayer spacing. Most adsorbed molecules are oriented parallel to the carbon plane of GO. However, as additional molecules are adsorbed into the interlaminations of GO, the adsorbed molecules are oriented perpendicular to the carbon plane of GO, and a large space forms between two GO interlayers. In addition, the role of large molecules in increasing interlayer spacing becomes more crucial than that of water molecules in the adsorption of binary solvent systems by GO.
基金supported by the National Natural Science Foundation of China (Nos. 21506208, 21476230 and 21376238)DICP DMTO201405
文摘A composite interlayer comprised of gadolinia doped ceria(GDC) and Co/Fe oxide was prepared and investigated for solid oxide electrolysis cell with yttrium stabilized zirconia(YSZ) electrolyte and LaSrCoFeO(LSCF) anode. The interlayer was constructed of a base layer of GDC and a top layer of discrete CoO/FeCoOparticles. The presence of the GDC layer drastically alleviated the undesired reactions between LSCF and YSZ, and the presence of Co/Fe oxide led to further performance improvement. At 800 °C and 45% humidity, the cell with 70% Co/Fe-GDC interlayer achieved 0.98 A/cmat 1.18 V, 14% higher than the cell without Co/Fe oxide. Electrochemical impedance spectroscopy(EIS) revealed that with higher Co/Fe content, both the ohmic resistance and the polarization resistance of the cell were reduced. It is suggested that Co/Fe oxide can react with the Sr species segregated from LSCF and Sr(Co,Fe)O, a compound with high catalytic activity and electronic conductivity. The Sr-capturing ability of Co/Fe oxide in combination with the Sr-blocking ability of GDC layer can effectively suppress the undesired reaction between LSCF and YSZ, and consequently improve the cell performance.
基金This work was supported by the National Science Foundation(CBET-1803256)Dr.C.Liu acknowledges the support from National Natural Science Foundation of China(52102277)the Fundamental Research Funds for the Central Universities,conducted by Tongji University.
文摘Vanadium oxides,par-ticularly hydrated forms like V_(2)O_(5)·nH_(2)O(VOH),stand out as promising cathode candidates for aqueous zinc ion batteries due to their adjustable layered structure,unique electronic characteristics,and high theoretical capacities.However,challenges such as vanadium dissolution,sluggish Zn^(2+)diffusion kinetics,and low operating voltage still hinder their direct application.In this study,we present a novel vanadium oxide([C_(6)H_(6)N(CH_(3))_(3)]_(1.08)V_(8)O_(20)·0.06H_(2)O,TMPA-VOH),developed by pre-inserting trimethylphenylammonium(TMPA+)cations into VOH.The incorporation of weakly polarized organic cations capitalizes on both ionic pre-intercalation and molecular pre-intercalation effects,resulting in a phase and morphology transition,an expansion of the interlayer distance,extrusion of weakly bonded interlayer water,and a substantial increase in V^(4+)content.These modifications synergistically reduce the electrostatic interactions between Zn^(2+)and the V-O lattice,enhancing structural stability and reaction kinetics during cycling.As a result,TMPA-VOH achieves an elevated open circuit voltage and operation voltage,exhibits a large specific capacity(451 mAh g^(-1)at 0.1 A g^(-1))coupled with high energy efficiency(89%),the significantly-reduced battery polarization,and outstanding rate capability and cycling stability.The concept introduced in this study holds great promise for the development of high-performance oxide-based energy storage materials.
基金financial supports from the National Natural Science Foundation of China (No.21506208,21376238,21476230,91534128)DICP DMTO201405
文摘Low temperature prepared(La;Sr;);MnO;-δ-Y;Zr;O;(LSM-YSZ) nano-composite cathode has high three-phase boundary(TPB) density and shows higher oxygen reduction reaction(ORR) activity than traditional LSM-YSZ cathode at reduced temperatures. But the weak connection between cathode and electrolyte due to low sintering temperature restrains the performance of LSM-YSZ nano-composite cathode. A YSZ interlayer, consisted of nanoparticles smaller than 10 nm, is introduced by spinning coating hydrolyzed YSZ sol solution on electrolyte and sintering at 800 °C. The thickness of the interlayer is about 150 nm. The YSZ interlayer intimately adheres to the electrolyte and shows obvious agglomeration with LSM-YSZ nano-composite cathode. The power densities of the cell with interlayer are 0.83, 0.46 and 0.21 W/cm;under 0.7 V at 800, 700 and 600 °C, respectively, which are 36%, 48% and 50% improved than that of original cell. The interlayer introduction slightly increases the ohmic resistance but significantly decreases the polarization resistance. The depressed high frequency arcs of impedance spectra suggest that the oxygen incorporation kinetics are enhanced at the boundary of YSZ interlayer and LSM-YSZ nanocomposite cathode, contributing to improved electrochemical performance of the cell with interlayer.
基金supported by the National Basic Research Program of China(Grant Nos.2016YFA0300701,2017YFA0206300,and 2017YFA0303601)the National Natural Science Foundation of China(Grant Nos.11520101002,51590880,and 11674378)
文摘We report a strong antiferromagnetic(AFM) interlayer coupling in ferromagnetic La_(0.67)Sr_(0.33)MnO_3/SrRuO_3(LSMO/SRO) superlattices grown on(111)-oriented SrTiO_3 substrate. Unlike the(001) superlattices for which the spin alignment between LSMO and SRO is antiparallel in the in-plane direction and parallel in the out-of-plane direction, the antiparallel alignment is observed along both the in-plane and out-of-plane directions in the present sample. The low temperature hysteresis loop demonstrates two-step magnetic processes, indicating the coexistence of magnetically soft and hard components. Moreover, an inverted hysteresis loop was observed. Exchange bias tuned by the temperature and cooling field was also investigated, and positive as well as negative exchange bias was observed at the same temperature with the variation of the cooling field. A very large exchange field(H_(EB)) was observed and both magnitude and sign of the H_(EB)depend on the cooling field, which can be attributed to an interplay of Zeeman energy and AFM coupling energy at the interfaces. The present work shows the great potential of tuning a spin texture through interfacial engineering for the complex oxides whose spin state is jointly determined by strongly competing mechanisms.
基金Project supported by the National Natural Science Foundation of China (Grant No 60376019).
文摘The paper reports that Hfrio dielectric is deposited by reactive co-sputtering of Hf and Ti targets in an Ar/O2 ambience, followed by an annealing in different gas ambiences of N2, NO and NH3 at 600℃ for 2 min. Capacitancevoltage and gate-leakage properties are characterized and compared. The results indicate that the NO-annealed sample exhibits the lowest interface-state and dielectric-charge densities and best device reliability. This is attributed to the fact that nitridation can create strong Si≡N bonds to passivate dangling Si bonds and replace strained Si-O bonds, thus the sample forms a hardened dielectric/Si interface with high reliability.
基金supported by the National Natural Science Foundation of China(No.51972258)Hubei Natural Science Foundation(No.2020CFB774)+1 种基金Open Fund by Sanya Science and Education Innovation Park of Wuhan University of Technology(No.2021KF0021)the Fundamental Research Funds for the Central Universities(No.WUT:20221VA002)。
文摘Vanadium pentoxide(V_(2)O_(5))with a layered structure is of great interest in the field of electrochromic(EC)due to its abundance of color variations.However,there are still a series of problems such as slow ion diffusion,poor electronic conductivity and cyclic stability in the reaction process.Herein,we successfully prepared a stable and fast multi-color electrochromic material V_(2)O_(5)-PEDOT by a simple“one-pot”method.The layer space of V_(2)O_(5)could be tuned by 3,4-ethylenedioxythiophene(named V_(2)O_(5)-PEDOT)during the dissolution and recrystallization of vanadium oxide.The expanded layer spacing facilitates rapid ion insertion and extraction.PEDOT serves as an internal conductive pillar to improve the overall conductivity of the material.The obtained intercrossing structure of the nanobelts shortens the ion diffusion distance and ensures electrolyte penetration.The V_(2)O_(5)-PEDOT exhibits the fast response time(1.1 s for coloration and 3.5 s for bleaching at 422 nm),high optical contrast(ΔT=45%at 422 nm andΔT=35.2%at 1000 nm),great coloration efficiency(CE=97.1 cm2/C),and high cyclic stability(86%preserved after 3000 cycles).The electrochromic devices(ECD)were successfully assembled by using V_(2)O_(5)-PEDOT films as ion storage layers and electrochromic layers,demonstrating remarkable performance.
基金financially supported by the National Natural Science Foundation of China(No.22076094)the Science&Technology Innovation Program of Shunde of Foshan City(China)(No.2130218002526)and the Tsinghua-Foshan Innovation Special Fund(China)(No.2021THFS0503).
文摘Copper intercalated birnessite MnO_(2)(δ-MnO_(2))with weak crystallinity and high specific surface area(421 m^(2)/g)was synthesized by a one-pot redox method and investigated for low-temperature CO oxidation.The molar ratio of Cu/Mn was as high as 0.37,which greatly weakened the Mn-O bond and created a lot of low-temperature active oxygen species.In situ DRIFTS revealed strong bonding of copper ions with CO.As-synthesized MnO_(2)-150Cu achieved 100%conversion of 250 ppm CO in normal air(3.1 ppm H_(2)O)even at−10°C under the weight-hourly space velocity(WHSV)of 150 L/(g·h).In addition,it showed high oxygen storage capacity to oxidize CO in inert atmosphere.Though the concurrent moisture in air significantly inhibited CO adsorption and its conversion at ambient temperature,MnO_(2)-150Cu could stably convert CO in 1.3%moisture air at 70°C owing to its great low-temperature activity and reduced competitive adsorption of water with increased temperature.This study discovers the excellent low-temperature activity of weakly crystallized δ-MnO_(2) induced by high content intercalated copper ions.
基金supported by the National Natural Science Foundation of China under Grant No.51975152.
文摘The oxide layer on the surface has always been a key obstacle to achieving the diffusion bonding of Al alloys.It is a challenge for performing diffusion bonding without removing oxide layers.Herein,diffusion bonding of Al alloy retaining continuous oxide layers was successfully achieved in the air by a low-temperature and low-pressure diffusion bonding mothed using a Zn interlayer.During the bonding processes,conducted at 360℃ and 3 MPa,Zn diffused into Al through cracks of thin oxide layers to form the joint composed Al/(diffusion layer)/(oxide layer)/(Zn)/(oxide layer)/(diffusion layer)/Al.The diffusion layers were composed of Zn-Al eutectoid,and the oxide layer included nanocrystals and amorphous Al_(2)O_(3).The shear strength of joints containing continuous oxide layers was about 30 MPa.Interestingly,the migration behavior toward the joint center of the interfacial oxide layers was observed with consuming of the Zn interlayer.The cracking phenomenon,the“subcutaneous diffusion”and the migration behavior of oxide layers were verified and analyzed by the diffusion bonding of anodized 6063Al-6063Al.Subsequently,the dynamic migration mechanism of oxide layers with elements diffusion and bonding interface strengths were discussed in detail.The ability to join Al alloys in the air at low temperatures and low pressure suggests a highly practical and economic method for diffusion bonding.
文摘The Turfan-Hami basin is the key area for the exploration of sandstone uranium deposits of the leachable interlayered oxidation zone type. The aim of this study is to shed light on the development characteristics of this type of uranium deposits and provide new clues to further exploration. Detailed study led to the following conclusions: (1) uranium orebodies are hosted mainly in the lower Middle Jurassic Xishanyao Formation and the lower Lower Jurassic Badaowan Formation; (2) the formation of uranium orebodies is closely related to organic matter; (3) the front of the interlayered oxidation zone is snake-shaped in plane and imbricated in the section; the more the interlayered oxidation zone and zonation are developed, the better the uranium mineralization will be; according to lithological and geochemical characteristics, the oxidation zone, the oxidation-reduction transitional zone and the reduction zone can be distin-guished; (4) the development of interlayered oxidation zone is controlled by geological structure, underground water, sandstone permeability and other factors; (5) sandstone uranium orebodies hosted in the interlayered oxidation zone are very complicated in spatial distribution, of which some are rolled and plated in shape and some are highly variable in shape.
文摘This paper reveals the physicochemical properties such as component, formulation, genesis, tem- perature, pH, Eh, salinity and pressure of all main alteration fluid of interlayer oxidation zone sand- stone-type uranium deposits after studying the geologic process and geochemistry of internal typical sandstone-type uranium deposits such as Shihongtan deposit in the Turpan-Hami basin, 512 deposit in the Yili basin, Dongsheng deposit in the Ordos basin. The composition of fluid can be divided into two parts based on the analysis of inclusion: one can be affirmed as atmospheric water with ordinary temperature epigenesist according to the character of hydrogen and oxygen isotope of inclusion, the other is natural gas containing gaseous hydrocarbon like CH4, and CO2 as well as a little H2S, CO, H2, N2 and so on, it always contains a small quantity of hydrocarbon liquid in petroliferous basins. The fluid property of oxidation alteration zone is always oxidation alkaline, and neutrality or weak acid-weak alkaline and reducibility during the metallizing process, but at secondary reduction or deoxidization zone it becomes strong reduction alkaline. Oxygenic groundwater in the fluid is the activate and mig- ratory medium of uranium element, but the gaseous hydrocarbon like CH4 as well as H2, H2S, CO from natural gas is the important sedimentary reducer of uranium mineral; the transformation of pH,Eh in fluid environment is the main reason for the formation of uranium metallization.
文摘Chemical oxidation and metal intercalation of natural graphite was utilized to increase the capacity and enhance the cycle property of graphite anodes in lithium ion batteries.
基金the National Natural Science Foundation of China (21875263)the Basic and Applied Basic Research Major Program of Guangdong Province (2019B030302007)。
文摘The large energy barrier in hole extraction still remains a great challenge in developing hole transporting layer (HTL) materials for organic solar cells (OSCs).Thus,solution-processed HTL materials with excellent hole collection ability and good compatibility with large-area processing technique are strongly desired for OSCs.Herein,we developed a cost-effective and solution-processed MoO_(3)HTL for efficient OSCs.By adding a small amount of glucose as reducing reagent into the ammonium molybdate precursor solution,a deeply n-doped MoO_(3),namely G:Mo,was prepared through the sol–gel method.Compared to pristine MoO_(3),the conductivity of G:Mo was enhanced by two orders of magnitude,which greatly improved the hole collection ability of the HTL.OSCs with G:Mo can exhibit comparable PCE to the PEDOT:PSS device.Using PBDB-TF:BTP-eC9 as the active layer,a PCE of 17.1%is obtained for the device,which is the highest PCE value for OSC using a solution-processed MoO_(3)HTL.More importantly,G:Mo is well compatible with the blade-coating processing.The OSC using a blade-coated G:Mo showed almost no PCE loss as compared to the device with spin-coated G:Mo HTL.The results from this work indicate that G:Mo is a promising HTL material for the practical production of OSCs.