Inhibiting dendrites formation and side-reactions is a critical challenge for practical application of aqueous Zn-ion batteries(AZIBs).Electrolyte additives offer an effective solution to address this problem.Inspired...Inhibiting dendrites formation and side-reactions is a critical challenge for practical application of aqueous Zn-ion batteries(AZIBs).Electrolyte additives offer an effective solution to address this problem.Inspired by using green corrosion inhibitor for metals,we introduce caffeine,extracted from tea-leaf,as an additive to achieve stable AZIBs.Caffeine,with its N and O containing groups,strongly adsorbs on the Zn anode and Zn^(2+)ions.This featured adsorption induces the replacement of water molecules from electric double layer(EDL)and solvation shell,suppressing side-reactions such as corrosion and hydrogen evolution reaction(HER).Moreover,the selective adsorption and steric hindrance of caffeine promote Zn(002)-oriented deposition,resulting in uniform and compact zinc deposits at both low and high current density and areal capacity.Due to the significantly suppressed dendrites and corrosion,the Coulomb Efficiency(CE)reaches 99.24%after 800 cycles,and the Zn||MnO_(2)battery shows a specific capacity of 167.2 mAh g^(−1)with 81%capacity retention after 1000 cycles at 2 A g^(−1).展开更多
This paper reports that dense and crack-free （100） oriented lead zirconate titanate （Pb（ Zr0. 52Ti0. 48 ）O3, PZT） thick film embedded with PZT nanopartieles has been successfully fabricated on Pt/Cr/SiO2/Si subs...This paper reports that dense and crack-free （100） oriented lead zirconate titanate （Pb（ Zr0. 52Ti0. 48 ）O3, PZT） thick film embedded with PZT nanopartieles has been successfully fabricated on Pt/Cr/SiO2/Si substrate by using PT transition layer and PVP additive. The thick film possesses single-phase perovskite structure and perfectly （100） oriented. The （100） orientation degree of the PZT films strongly depended on annealing time and for the 4μm-thick PZT film which was annealed at 700℃ for 5 min is the largest. The （100） orientation degree of the PZT thick film gradually strengthen along with the thickness of film decreasing. The 3μm-thick PZT thick film which was annealed at 700℃ for 5 rain has the strongest （100） orientation degree, which is 82. 3%.展开更多
CaBi2Nb2O9 (CBNO) ceramics was prepared at 1050℃ using regular flake-like CBNO powders as the precursor, and synthe-sized by the molten salts synthesis method. The tropism degree and microstructure of the ceramics we...CaBi2Nb2O9 (CBNO) ceramics was prepared at 1050℃ using regular flake-like CBNO powders as the precursor, and synthe-sized by the molten salts synthesis method. The tropism degree and microstructure of the ceramics were analyzed, and the die-lectric, ferroelectric and piezoelectric properties were characterized. Compared with conventional methods, the properties of CBNO ceramics by the new preparation method were found to be better. As the sinter temperature decreases, the grain growth becomes regular with textured features. The polarization process becomes easy to be realized at room temperature. Moreover, the dielectric loss decreases and the piezoelectric constant increases significantly.展开更多
Optimizing the orientation of β-Ga_(2)O_(3) has emerged as an effective strategy to design high-performance β-Ga_(2)O_(3) device,but the orientation growth mechanism and approach have not been revealed yet.Herein,by...Optimizing the orientation of β-Ga_(2)O_(3) has emerged as an effective strategy to design high-performance β-Ga_(2)O_(3) device,but the orientation growth mechanism and approach have not been revealed yet.Herein,by employing AlN buffer layer,the highly preferred orientation of β-Ga_(2)O_(3)(100)film rather than(-201)film is realized on 4H-SiC substrate at low sputtering power and temperature.Because β-Ga_(2)O_(3)(100)film exhibits a slower growth speed than(-201)film,the former possesses the higher dangling bond density and the lower nucleation energy,and a large conversion barrier exists between these two ori-entations.Moreover,the AlN buffer layer can suppress the surface oxidation of the 4H-SiC substrate and eliminate the strain of β-Ga_(2)O_(3)(100)film,which further reduces the nucleation energy and en-larges the conversion barrier.Meanwhile,the AlN buffer layer can increase the oxygen vacancy formation energy and decrease the oxygen vacancy concentration of β-Ga_(2)O_(3)(100)film.Consequently,the solar-blind photodetector based on the oriented film exhibits the outstanding detectivity of 1.22×10^(12) Jones and photo-to-dark current ratio of 1.11×10^(5),which are the highest among the reported β-Ga_(2)O_(3) solar-blind photodetector on the SiC substrate.Our results offer in-depth insights into the preferred orientation growth mechanism,and provide an effective way to design high-quality β-Ga_(2)O_(3)(100)orientation film and high-performance solar-blind photodetector.展开更多
Aqueous zinc-ion batteries(AZIBs)are currently confronted with the challenge of achieving long-term cyclic stability under high current densities.This issue is primarily attributed to the excessive growth of dendrites...Aqueous zinc-ion batteries(AZIBs)are currently confronted with the challenge of achieving long-term cyclic stability under high current densities.This issue is primarily attributed to the excessive growth of dendrites and the occurrence of significant side reactions.Herein,sucralose(SCL),as an electrolyte additive,has been used to promote the exposure of the Zn(002)texture.The introduction of SCL can adjust the Zn~(2+)nucleation and diffusion along different crystal facets,promoting the exposure of the Zn(002)texture.By substituting water molecules in the[Zn(H_(2)O)_(6)]~(2+),SCL reconfigures the hydrogen bond network in the electrolyte,reconstructing the solvation structure and suppressing the hydrogen evolution reaction.Consequently,the Zn//Zn symmetric battery exhibits long-term cycling stability of over 4900 h at 1 mA cm^(-2)-1 mAh cm^(-2).Even at a harsh condition of 30 mA cm^(-2)-30 mAh cm^(-2)(DOD=73.3%),it can stably cycle for 171 h.The CE of the Zn//Cu half battery reaches 99.61% at 0.2 mA cm^(-2)with 0.2 mAh cm^(-2).Employing the optimized electrolyte,after 500 cycles,a high specific capacity of 420 mAh g^(-1)can be retained for the NH_4V_4O_(10)//Zn full battery at 500 mA g^(-1),corresponding to a capacity retention of 90.7%.展开更多
Based on the cellular automaton （CA） method, a numerical model was developed to simulate the dendritic growth of magnesium alloy with HCP crystal structure. The growth kinetics was calculated from the complete solut...Based on the cellular automaton （CA） method, a numerical model was developed to simulate the dendritic growth of magnesium alloy with HCP crystal structure. The growth kinetics was calculated from the complete solution of the transport equations. By defining a special neighborhood configuration with the square CA cell, and using a set of capturing rules which were proposed by BELTRAN-SANCHEZ and STEFANESCU for the dendritic growth of cubic crystal metals during solidification, modeling of dendritic growth of magnesium alloy with different growth orientations was achieved. Simulation of equiaxed dendritic growth and columnar dendritic growth under directional solidification was carried out, and validation was performed by comparing the simulated results with the experimental results and those in the previously published works.展开更多
A series of Eu-doped ZnO films were prepared by a sol-gel method. Precursor and films were characterized by thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), UV-vis spectra, as we...A series of Eu-doped ZnO films were prepared by a sol-gel method. Precursor and films were characterized by thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), UV-vis spectra, as well as the magnetism measurement. The wurtzite structure of obtained films presents an extreme high c-orientation character. The film susceptibility resembles a Curie-Weiss behavior at high temperature, and presents an obvious enhancement at low temperature, indicating the presence of antiferromagnetic interactions in the Zn0.9Eu0.1O films.展开更多
The microstructure evolution and growth orientation of directionally solidified Mg-4 wt% Zn alloy in the growth rate range from 20 to 200μm/s were investigated. A typical cellular structure was observed with a growth...The microstructure evolution and growth orientation of directionally solidified Mg-4 wt% Zn alloy in the growth rate range from 20 to 200μm/s were investigated. A typical cellular structure was observed with a growth rate of 20 μm/s, and the cellular spacing was 115 μm. When the growth rate increased to 60 μm/s, cellular structure with some developed perturbations was obtained and the cellular spacing was 145 μm, suggesting that the cell-to-dendrite transition happened at the growth rate lower than 60 μm/s. As the growth rate further increased, the microstructure was dendritic and the primary dendritic arm spacing decreased. The relationship between the primary dendritic arm spacings and the growth rates was in good agreement with Trivedi model during dendritic growth. Besides, X-ray diffraction and transmission electron microscopy analyses showed that the growth direction of directionally solidified Mg-4 wt% Zn alloy was （1120） lay in {0002} crystal plane, and the preferred orientation was explained with the lattice vibration model for one-dimensional monatomic chain.展开更多
Metal organic frameworks(MOFs)has broad application prospect in separation,catalysis,and adsorption.By a facile green method,we successfully fabricated prGO@cHKUST-1 composite membrane with the modification of dopamin...Metal organic frameworks(MOFs)has broad application prospect in separation,catalysis,and adsorption.By a facile green method,we successfully fabricated prGO@cHKUST-1 composite membrane with the modification of dopamine and orientated growth of MOFs.Mg/AI-layered double hydroxides(Mg/Al-LDHs)was used as a modulator to obtain cubic HKUST-1(cHKUST-1)with excellent morphology and special properties.Scanning Electron Microscopy(SEM),X-ray diffraction(XRD),and Fourier transform infrared spectroscopy(FTIR)etc.characte rization illustrated successful synthesis of cHKUST-1 and composite membranes.Cubic HKUST-1 can tune the inter-layer spacing of graphene oxide(GO)leading increase in hydrophilicity and flux of the membrane.Meanwhile,the reduction effect of PDA and intercalation effect of MOFs could change the stacked way of GO layers,forming several fuzzy pores and more active sites on membrane surface.The prGO@cHKUST-1 membrane has an excellent rejection for methylene blue(MB)(99.5%)and Congo red(CR)(71.2%).Moreover,the modified membra ne exhibited 10 and 5 times higher permeation flux than that of original GO membrane and prGO membrane,respectively.Thus,using orientated growth of MOFs to synthesize GO based composite membrane will provide useful insights in ultrahigh permeation flux membranes of dye and oil-water emulsion separation.展开更多
Due to the important role ofδphase's quantity and morphology in the mechanical and fatigue properties of Inconel 718 alloy and its components,it is necessary to renew insights into the effect of cold deformation ...Due to the important role ofδphase's quantity and morphology in the mechanical and fatigue properties of Inconel 718 alloy and its components,it is necessary to renew insights into the effect of cold deformation on theδphase precipitation,especially on the morphology evolution.Therefore,the nucleation and growth behavior ofδphase in cold-rolled Inconel 718 alloy during aging were investigated.The results show that the precipitation rate and volume fraction ofδphase increase with increasing the cold rolling reduction from 10%to 50%.The volume fraction ofδphase reaches equilibrium after 5 h,remaining at 5.98%,6.52%,and 6.79%under different rolling reductions(10%,30%,and 50%),respectively.The nucleation ofδphase mainly occurs on different sites(grain boundaries,new twin boundaries and old twin boundaries)under 10%rolling reduction,whileδphase mainly nucleates on the new grain boundaries of static recrystallization due to 50%rolling reduction.And the growth ofδphase undergoes a process of alternate orientation growth from spherical(nucleation)→short rod(longitudinal orientation growth)→short rod(radial orientation growth)→dynamic equilib-rium.Under 10%rolling reduction,δphase tends to grow into the matrix,while under 50%rolling reduction,the orientation grows faster and is easily affected by the grain boundary curvature.展开更多
The characteristic of crystal growth of NdFeB cast alloys was studied. It is found that the crystal growth orientation of conventional ingots is along <410> or <411>. As the cooling rate increases, the cry...The characteristic of crystal growth of NdFeB cast alloys was studied. It is found that the crystal growth orientation of conventional ingots is along <410> or <411>. As the cooling rate increases, the crystallization orientation changes from a axis to c axis, along which the grain is easy to be magnetized. Meanwhile, by analyzing the change of crystallization orientation, the influence on the property of magnets was discussed.展开更多
The pure Mg with columnar crystals was prepared by directional solidification,and the effect of process parameters on the crystal orientation and tensile properties was studied.Moreover,the microstructure evolution du...The pure Mg with columnar crystals was prepared by directional solidification,and the effect of process parameters on the crystal orientation and tensile properties was studied.Moreover,the microstructure evolution during tensile deformation was analyzed by electron backscatter diffraction(EBSD)technology.Furthermore,the slip within adjacent grains and grain boundary strain were discussed using the bicrystal model theory.The results show that the microstructure of the pure Mg at a pulling rate of 200μm/s is columnar polycrystal with growth orientation concentrated in<022ˉ5>,and no transverse grain boundaries can be seen.In addition,the Schmid factors(SFs)of basalslips in columnar crystals are higher than 0.43 under tensile stress.Moreover,the geometric compatibility factor of slip systems on both sides of grain boundaries is greater than 0.7,showing good strain coordination ability of grain boundaries.Therefore,the elongation of the directionally solidified pure Mg is as high as 53%at room temperature.展开更多
A facile method was introduced and demonstrated to synthesize zinc oxide(ZnO) nanorods(NRs) as an electron transporting layer(ETL) for organic solar cells(OSCs).Hydrothermal synthesis of the NRs showed a constant grow...A facile method was introduced and demonstrated to synthesize zinc oxide(ZnO) nanorods(NRs) as an electron transporting layer(ETL) for organic solar cells(OSCs).Hydrothermal synthesis of the NRs showed a constant growth rate of 5.5 nm min-1 from germination to sub-micrometer length.The properties were characterized using scanning electron microscopy(SEM),transmission electron microscopy(TEM),absorption spectrophotometry and so on.Based on these measurements,the germinant growth mechanism and its corresponding orientation characteristics were investigated.As an ETL of the OSCs,ZnO NRs enhance the charge extraction from the active layer due to their increased interfacial surface area,but there is an optimal length because of the shunt path formation and UV absorption of long ZnO NRs.As a re sult,the OSC with the ZnO NRs as ETL shows power conversion efficiency(PCE) up to 6.2%.The J-V characteristics and incident photon-to-current conversion efficiency(IPCE) measurement also reveal that the efficiency enhancement is an assembly of individual results from optical,physical and electrical characteristic of the ZnO NRs.展开更多
Oriented nanobelts of manganese oxide have been firstly and successfully prepared by a microemulsion technique under controlled circumstances. The samples were characterized by X-ray diffraction (XRD), transmission el...Oriented nanobelts of manganese oxide have been firstly and successfully prepared by a microemulsion technique under controlled circumstances. The samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM). Influences of sodium chloride and annealed temperature on the synthesis of Mn3O4 nanobelts were investigated. It was found that NaCI is the key factor to synthesize oriented Mn3O4 nanobelts and 827 K is optimum temperature to produce fine nanobelts. Oriented growth mechanism of Mn3O4 nanobelts was discussed.展开更多
Interaction of straight chain alcohol vapors with MOF-199-functionalized films was studied by SPR. The signals had linear relationships with the concentration of alcohols over a wide range from 0 to 70% （v/v） and we...Interaction of straight chain alcohol vapors with MOF-199-functionalized films was studied by SPR. The signals had linear relationships with the concentration of alcohols over a wide range from 0 to 70% （v/v） and were reversible in proportional to the chain length, with R2 all above 0.99.展开更多
The relationship between the solid/liquid interface and the crystal orientation for pure magnesium,which grows in fashion of cellular crystal in unidirectional solidification,was investigated.The results show that the...The relationship between the solid/liquid interface and the crystal orientation for pure magnesium,which grows in fashion of cellular crystal in unidirectional solidification,was investigated.The results show that the energy of the solid/liquid interface is the lowest during cellular crystal growth of pure magnesium;and the solid/liquid interface is covered by the basal face{0001}and by the crystal face made up of three atoms located at the orientation{0001}0100and two atoms located at the inner of magnesium crystal cell.The strongest bond is formed in the direction of 61.9°viating from the growth direction,and the second strong bond is formed in the directions of 8.5°d 47.7°espectively,deviating from the growth direction.The angle between the basal face{0001} and the growth direction is 61.9°he theoretical analysis results are basically consistent with the experimental results from SUSUMU et al.展开更多
With the support by the National Natural Science Foundation of China,the research team led by Professor Li Yigang(李毅刚)at Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine and Professor ...With the support by the National Natural Science Foundation of China,the research team led by Professor Li Yigang(李毅刚)at Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine and Professor Peng Huisheng(彭慧胜)at Fudan University presented a new type of展开更多
The orientation is the key factor to determine the physicochemical properties of the metal-organic framework(MOF)films.New strategies for oriented MOF films are of fundamental importance in the advancement of science ...The orientation is the key factor to determine the physicochemical properties of the metal-organic framework(MOF)films.New strategies for oriented MOF films are of fundamental importance in the advancement of science and technology.Here we report a unified approach to the synthesis of a large variety of porphyrin-based MOF films with different directions,chemistries and properties.This strategy is based on a general electrochemical regulation of coordination process of different metal cation(M_(1)=Zn,Co,Ni,Ce)and tetra(4-carboxyphenyl)porphyrin(M_(2)TCPP,M_(2)=H,Cu,Pt,Pd)on various conductive substrates.The cathode strategy relies on the reduction of M_(2)TCPP ligands and follows the electrochemical reaction mechanism to achieve effective control over crystallizing M_(1)-M_(2)TCPP MOF films oriented in the(110)direction.The highly oriented M_(1)-M_(2)TCPP MOF films are endowed with excellent crystalline,spatial network structure and hierarchical three-dimensional pore structure,which is conducive to charge transfer and material transmission and suitable for use as an electrochemical catalyst.The Zn-TCPP MOF films on conductive substrate could be used directly as an electrochemical sensor for electrocatalytic oxidation of NaNO2,and showed wide linear range,low limit of detection(0.24μM),high sensitivity(285.8 mA/(mM·cm2))and good anti-interference performance.We believe our methodology provides a simple and convenient route to a variety of oriented porphyrin-based MOF films for nanodevices with novel structure and function in nanotechnology.展开更多
Shaping crystalline porous materials such as metal organic frameworks （MOFs） and zeolites into two-dimensional （2D） nanosheet forms is highly desirable for developing high-performance molecular sieving membranes. ...Shaping crystalline porous materials such as metal organic frameworks （MOFs） and zeolites into two-dimensional （2D） nanosheet forms is highly desirable for developing high-performance molecular sieving membranes. However, conventional exfoliation-deposition is complex and challenging for the large-scale fabrication of nanosheet MOF tubular membranes. Here, for the first time, we report a direct growth technique by ZnO self-conversion and ammonia assistance to fabricate zeolitic imidazolate framework （ZIF） membranes consisting of 2D nanosheets on porous hollow fiber substrates; the membranes are suitable for large-scale industrial gas separation processes. The proposed fabrication process for ZIF nanosheet membranes is based on the localized self-conversion of a pre-deposited thin layer of ZnO in a ligand solution containing ammonium hydroxide as a modulator. The resulting ZIF 2D nanosheet tubular membrane is highly oriented and only 50 nm in thickness. It exhibits excellent molecular sieving performance, with high H2 permeance and selectivity for H2/CO2 separation. This technique shows great promise in MOF nanosheet membrane fabrication for large-scale molecular sieving applications.展开更多
基金supported by the Foundation of Guangxi Innovation Driven Development Project Grant(AA22068080)the Science and Technology Plan of Guangxi(No.ZY22096019,ZY20220101)+1 种基金the National Natural Science Foundation of China(No.52474431)the Research Plan of International Collaboration Fund for Creative Research Teams(ICFCRT)of NSFC(No.W2441008)。
文摘Inhibiting dendrites formation and side-reactions is a critical challenge for practical application of aqueous Zn-ion batteries(AZIBs).Electrolyte additives offer an effective solution to address this problem.Inspired by using green corrosion inhibitor for metals,we introduce caffeine,extracted from tea-leaf,as an additive to achieve stable AZIBs.Caffeine,with its N and O containing groups,strongly adsorbs on the Zn anode and Zn^(2+)ions.This featured adsorption induces the replacement of water molecules from electric double layer(EDL)and solvation shell,suppressing side-reactions such as corrosion and hydrogen evolution reaction(HER).Moreover,the selective adsorption and steric hindrance of caffeine promote Zn(002)-oriented deposition,resulting in uniform and compact zinc deposits at both low and high current density and areal capacity.Due to the significantly suppressed dendrites and corrosion,the Coulomb Efficiency(CE)reaches 99.24%after 800 cycles,and the Zn||MnO_(2)battery shows a specific capacity of 167.2 mAh g^(−1)with 81%capacity retention after 1000 cycles at 2 A g^(−1).
基金Sponsored by 863 Scientific Project of China (Grant No.2007AA03Z103)the National Natural Science Foundation of China (Grant No.50742007)the Key Laboratory Foundation of Sonar Technology of China(Grant No. 9140C24KF0901)
文摘This paper reports that dense and crack-free （100） oriented lead zirconate titanate （Pb（ Zr0. 52Ti0. 48 ）O3, PZT） thick film embedded with PZT nanopartieles has been successfully fabricated on Pt/Cr/SiO2/Si substrate by using PT transition layer and PVP additive. The thick film possesses single-phase perovskite structure and perfectly （100） oriented. The （100） orientation degree of the PZT films strongly depended on annealing time and for the 4μm-thick PZT film which was annealed at 700℃ for 5 min is the largest. The （100） orientation degree of the PZT thick film gradually strengthen along with the thickness of film decreasing. The 3μm-thick PZT thick film which was annealed at 700℃ for 5 rain has the strongest （100） orientation degree, which is 82. 3%.
基金supported by the National Natural Science Foundation of China (50632030 & 10804130)
文摘CaBi2Nb2O9 (CBNO) ceramics was prepared at 1050℃ using regular flake-like CBNO powders as the precursor, and synthe-sized by the molten salts synthesis method. The tropism degree and microstructure of the ceramics were analyzed, and the die-lectric, ferroelectric and piezoelectric properties were characterized. Compared with conventional methods, the properties of CBNO ceramics by the new preparation method were found to be better. As the sinter temperature decreases, the grain growth becomes regular with textured features. The polarization process becomes easy to be realized at room temperature. Moreover, the dielectric loss decreases and the piezoelectric constant increases significantly.
基金supported by the National Key Research and Development Program of China(No.2021YFA0715600)the National Natural Science Foundation of China(Nos.62274125,52192611)+2 种基金the Guangdong Basic and Applied Basic Research Fund(No.2023A1515030084)the Key Research and Development Program of Shaanxi Province(Grant No.2024GX-YBXM-410)the fund of the State Key Laboratory of Solidification Processing in NWPU(No.SKLSP202220).
文摘Optimizing the orientation of β-Ga_(2)O_(3) has emerged as an effective strategy to design high-performance β-Ga_(2)O_(3) device,but the orientation growth mechanism and approach have not been revealed yet.Herein,by employing AlN buffer layer,the highly preferred orientation of β-Ga_(2)O_(3)(100)film rather than(-201)film is realized on 4H-SiC substrate at low sputtering power and temperature.Because β-Ga_(2)O_(3)(100)film exhibits a slower growth speed than(-201)film,the former possesses the higher dangling bond density and the lower nucleation energy,and a large conversion barrier exists between these two ori-entations.Moreover,the AlN buffer layer can suppress the surface oxidation of the 4H-SiC substrate and eliminate the strain of β-Ga_(2)O_(3)(100)film,which further reduces the nucleation energy and en-larges the conversion barrier.Meanwhile,the AlN buffer layer can increase the oxygen vacancy formation energy and decrease the oxygen vacancy concentration of β-Ga_(2)O_(3)(100)film.Consequently,the solar-blind photodetector based on the oriented film exhibits the outstanding detectivity of 1.22×10^(12) Jones and photo-to-dark current ratio of 1.11×10^(5),which are the highest among the reported β-Ga_(2)O_(3) solar-blind photodetector on the SiC substrate.Our results offer in-depth insights into the preferred orientation growth mechanism,and provide an effective way to design high-quality β-Ga_(2)O_(3)(100)orientation film and high-performance solar-blind photodetector.
基金supported by the Anhui Provincial Science and Technology Innovation Initiative(202423i08050051)the Anhui Provincial Natural Science Foundation(2408085MB029)+1 种基金the HFIPS Director’s Fund(YZJJGGZX202201)the Natural Science Foundation of Hebei Province of China(B2024402018)。
文摘Aqueous zinc-ion batteries(AZIBs)are currently confronted with the challenge of achieving long-term cyclic stability under high current densities.This issue is primarily attributed to the excessive growth of dendrites and the occurrence of significant side reactions.Herein,sucralose(SCL),as an electrolyte additive,has been used to promote the exposure of the Zn(002)texture.The introduction of SCL can adjust the Zn~(2+)nucleation and diffusion along different crystal facets,promoting the exposure of the Zn(002)texture.By substituting water molecules in the[Zn(H_(2)O)_(6)]~(2+),SCL reconfigures the hydrogen bond network in the electrolyte,reconstructing the solvation structure and suppressing the hydrogen evolution reaction.Consequently,the Zn//Zn symmetric battery exhibits long-term cycling stability of over 4900 h at 1 mA cm^(-2)-1 mAh cm^(-2).Even at a harsh condition of 30 mA cm^(-2)-30 mAh cm^(-2)(DOD=73.3%),it can stably cycle for 171 h.The CE of the Zn//Cu half battery reaches 99.61% at 0.2 mA cm^(-2)with 0.2 mAh cm^(-2).Employing the optimized electrolyte,after 500 cycles,a high specific capacity of 420 mAh g^(-1)can be retained for the NH_4V_4O_(10)//Zn full battery at 500 mA g^(-1),corresponding to a capacity retention of 90.7%.
基金Projects (2010DFA72760, 2011BAE22B02, 2011ZX04014-052, 2011ZX04001-071) supported by the Ministry of Science and Technology of China
文摘Based on the cellular automaton （CA） method, a numerical model was developed to simulate the dendritic growth of magnesium alloy with HCP crystal structure. The growth kinetics was calculated from the complete solution of the transport equations. By defining a special neighborhood configuration with the square CA cell, and using a set of capturing rules which were proposed by BELTRAN-SANCHEZ and STEFANESCU for the dendritic growth of cubic crystal metals during solidification, modeling of dendritic growth of magnesium alloy with different growth orientations was achieved. Simulation of equiaxed dendritic growth and columnar dendritic growth under directional solidification was carried out, and validation was performed by comparing the simulated results with the experimental results and those in the previously published works.
基金Project supported by the National Natural Science Foundation of China (20331030, 20373004) the Program for New Century Excellent Talents in University (NCET-04-0164) Engineering Research Institute, Peking University ( ERIPKU-204030)
文摘A series of Eu-doped ZnO films were prepared by a sol-gel method. Precursor and films were characterized by thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), UV-vis spectra, as well as the magnetism measurement. The wurtzite structure of obtained films presents an extreme high c-orientation character. The film susceptibility resembles a Curie-Weiss behavior at high temperature, and presents an obvious enhancement at low temperature, indicating the presence of antiferromagnetic interactions in the Zn0.9Eu0.1O films.
文摘The microstructure evolution and growth orientation of directionally solidified Mg-4 wt% Zn alloy in the growth rate range from 20 to 200μm/s were investigated. A typical cellular structure was observed with a growth rate of 20 μm/s, and the cellular spacing was 115 μm. When the growth rate increased to 60 μm/s, cellular structure with some developed perturbations was obtained and the cellular spacing was 145 μm, suggesting that the cell-to-dendrite transition happened at the growth rate lower than 60 μm/s. As the growth rate further increased, the microstructure was dendritic and the primary dendritic arm spacing decreased. The relationship between the primary dendritic arm spacings and the growth rates was in good agreement with Trivedi model during dendritic growth. Besides, X-ray diffraction and transmission electron microscopy analyses showed that the growth direction of directionally solidified Mg-4 wt% Zn alloy was （1120） lay in {0002} crystal plane, and the preferred orientation was explained with the lattice vibration model for one-dimensional monatomic chain.
基金the key projects of science and technology of Science&Technology Department of Sichuan Province(No.2018GZ0421)。
文摘Metal organic frameworks(MOFs)has broad application prospect in separation,catalysis,and adsorption.By a facile green method,we successfully fabricated prGO@cHKUST-1 composite membrane with the modification of dopamine and orientated growth of MOFs.Mg/AI-layered double hydroxides(Mg/Al-LDHs)was used as a modulator to obtain cubic HKUST-1(cHKUST-1)with excellent morphology and special properties.Scanning Electron Microscopy(SEM),X-ray diffraction(XRD),and Fourier transform infrared spectroscopy(FTIR)etc.characte rization illustrated successful synthesis of cHKUST-1 and composite membranes.Cubic HKUST-1 can tune the inter-layer spacing of graphene oxide(GO)leading increase in hydrophilicity and flux of the membrane.Meanwhile,the reduction effect of PDA and intercalation effect of MOFs could change the stacked way of GO layers,forming several fuzzy pores and more active sites on membrane surface.The prGO@cHKUST-1 membrane has an excellent rejection for methylene blue(MB)(99.5%)and Congo red(CR)(71.2%).Moreover,the modified membra ne exhibited 10 and 5 times higher permeation flux than that of original GO membrane and prGO membrane,respectively.Thus,using orientated growth of MOFs to synthesize GO based composite membrane will provide useful insights in ultrahigh permeation flux membranes of dye and oil-water emulsion separation.
基金The authors are grateful to the Province Natural Science Foundation of Zhejiang(Grant No.LQ19E050004)for financial support.The authors also graciously thank China Airlines Shenyang Liming Aeroengine Co.,Ltd.for aiding in providing the experimental Inconel 718 alloys.
文摘Due to the important role ofδphase's quantity and morphology in the mechanical and fatigue properties of Inconel 718 alloy and its components,it is necessary to renew insights into the effect of cold deformation on theδphase precipitation,especially on the morphology evolution.Therefore,the nucleation and growth behavior ofδphase in cold-rolled Inconel 718 alloy during aging were investigated.The results show that the precipitation rate and volume fraction ofδphase increase with increasing the cold rolling reduction from 10%to 50%.The volume fraction ofδphase reaches equilibrium after 5 h,remaining at 5.98%,6.52%,and 6.79%under different rolling reductions(10%,30%,and 50%),respectively.The nucleation ofδphase mainly occurs on different sites(grain boundaries,new twin boundaries and old twin boundaries)under 10%rolling reduction,whileδphase mainly nucleates on the new grain boundaries of static recrystallization due to 50%rolling reduction.And the growth ofδphase undergoes a process of alternate orientation growth from spherical(nucleation)→short rod(longitudinal orientation growth)→short rod(radial orientation growth)→dynamic equilib-rium.Under 10%rolling reduction,δphase tends to grow into the matrix,while under 50%rolling reduction,the orientation grows faster and is easily affected by the grain boundary curvature.
文摘The characteristic of crystal growth of NdFeB cast alloys was studied. It is found that the crystal growth orientation of conventional ingots is along <410> or <411>. As the cooling rate increases, the crystallization orientation changes from a axis to c axis, along which the grain is easy to be magnetized. Meanwhile, by analyzing the change of crystallization orientation, the influence on the property of magnets was discussed.
基金Projects(51775099,51675092)supported by the National Natural Science Foundation of ChinaProjects(E2021501019,E2022501001,E2022501006)supported by the Natural Science Foundation of Hebei Province,China。
文摘The pure Mg with columnar crystals was prepared by directional solidification,and the effect of process parameters on the crystal orientation and tensile properties was studied.Moreover,the microstructure evolution during tensile deformation was analyzed by electron backscatter diffraction(EBSD)technology.Furthermore,the slip within adjacent grains and grain boundary strain were discussed using the bicrystal model theory.The results show that the microstructure of the pure Mg at a pulling rate of 200μm/s is columnar polycrystal with growth orientation concentrated in<022ˉ5>,and no transverse grain boundaries can be seen.In addition,the Schmid factors(SFs)of basalslips in columnar crystals are higher than 0.43 under tensile stress.Moreover,the geometric compatibility factor of slip systems on both sides of grain boundaries is greater than 0.7,showing good strain coordination ability of grain boundaries.Therefore,the elongation of the directionally solidified pure Mg is as high as 53%at room temperature.
基金This study was conducted with support from the Korea Institute of Industrial Technology as Research Source Technique Project(KITECH,EO-190008)。
文摘A facile method was introduced and demonstrated to synthesize zinc oxide(ZnO) nanorods(NRs) as an electron transporting layer(ETL) for organic solar cells(OSCs).Hydrothermal synthesis of the NRs showed a constant growth rate of 5.5 nm min-1 from germination to sub-micrometer length.The properties were characterized using scanning electron microscopy(SEM),transmission electron microscopy(TEM),absorption spectrophotometry and so on.Based on these measurements,the germinant growth mechanism and its corresponding orientation characteristics were investigated.As an ETL of the OSCs,ZnO NRs enhance the charge extraction from the active layer due to their increased interfacial surface area,but there is an optimal length because of the shunt path formation and UV absorption of long ZnO NRs.As a re sult,the OSC with the ZnO NRs as ETL shows power conversion efficiency(PCE) up to 6.2%.The J-V characteristics and incident photon-to-current conversion efficiency(IPCE) measurement also reveal that the efficiency enhancement is an assembly of individual results from optical,physical and electrical characteristic of the ZnO NRs.
基金support from the National Natural Science Foundation of China under grant No.550071028Program of Science and Technology Bureau of Qingdao under grant No.03-2-IR-18
文摘Oriented nanobelts of manganese oxide have been firstly and successfully prepared by a microemulsion technique under controlled circumstances. The samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM). Influences of sodium chloride and annealed temperature on the synthesis of Mn3O4 nanobelts were investigated. It was found that NaCI is the key factor to synthesize oriented Mn3O4 nanobelts and 827 K is optimum temperature to produce fine nanobelts. Oriented growth mechanism of Mn3O4 nanobelts was discussed.
基金supported by NSFC(Nos.21027003, 21235007 and 91117010)Ministry of Science and Technology(No. 2012IM030400) and Chinese Academy of Sciences
文摘Interaction of straight chain alcohol vapors with MOF-199-functionalized films was studied by SPR. The signals had linear relationships with the concentration of alcohols over a wide range from 0 to 70% （v/v） and were reversible in proportional to the chain length, with R2 all above 0.99.
基金Project(2007T078)supported by the Outstanding Innovation Team in Colleges and Universities of Education Department of Liaoning Province,China
文摘The relationship between the solid/liquid interface and the crystal orientation for pure magnesium,which grows in fashion of cellular crystal in unidirectional solidification,was investigated.The results show that the energy of the solid/liquid interface is the lowest during cellular crystal growth of pure magnesium;and the solid/liquid interface is covered by the basal face{0001}and by the crystal face made up of three atoms located at the orientation{0001}0100and two atoms located at the inner of magnesium crystal cell.The strongest bond is formed in the direction of 61.9°viating from the growth direction,and the second strong bond is formed in the directions of 8.5°d 47.7°espectively,deviating from the growth direction.The angle between the basal face{0001} and the growth direction is 61.9°he theoretical analysis results are basically consistent with the experimental results from SUSUMU et al.
文摘With the support by the National Natural Science Foundation of China,the research team led by Professor Li Yigang(李毅刚)at Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine and Professor Peng Huisheng(彭慧胜)at Fudan University presented a new type of
基金supported by the National Natural Science Foundation of China(Nos.21422102,21171049,21501045,21403054,and 22405072)Postdoctoral Fellowship Program of CPSF(No.GZC20230673)+3 种基金Program for Science&Technology Innovation Talents in Universities of Henan Province(No.13HASTIT009)Program for Changjiang Scholars and Innovative Research Team in University(No.PCS IRT1126)China Postdoctoral Science Foundation(No.2024M760782)Key Research Projects of Higher Education Institutions in Henan Province(No.24A150003).
文摘The orientation is the key factor to determine the physicochemical properties of the metal-organic framework(MOF)films.New strategies for oriented MOF films are of fundamental importance in the advancement of science and technology.Here we report a unified approach to the synthesis of a large variety of porphyrin-based MOF films with different directions,chemistries and properties.This strategy is based on a general electrochemical regulation of coordination process of different metal cation(M_(1)=Zn,Co,Ni,Ce)and tetra(4-carboxyphenyl)porphyrin(M_(2)TCPP,M_(2)=H,Cu,Pt,Pd)on various conductive substrates.The cathode strategy relies on the reduction of M_(2)TCPP ligands and follows the electrochemical reaction mechanism to achieve effective control over crystallizing M_(1)-M_(2)TCPP MOF films oriented in the(110)direction.The highly oriented M_(1)-M_(2)TCPP MOF films are endowed with excellent crystalline,spatial network structure and hierarchical three-dimensional pore structure,which is conducive to charge transfer and material transmission and suitable for use as an electrochemical catalyst.The Zn-TCPP MOF films on conductive substrate could be used directly as an electrochemical sensor for electrocatalytic oxidation of NaNO2,and showed wide linear range,low limit of detection(0.24μM),high sensitivity(285.8 mA/(mM·cm2))and good anti-interference performance.We believe our methodology provides a simple and convenient route to a variety of oriented porphyrin-based MOF films for nanodevices with novel structure and function in nanotechnology.
基金This work was supported by the National Natural Science Foundation of China （Nos. 21476039 and 21076030）. M. T. thanks the Marie S~odowska-Curie Individual Fellowship for a postdoctoral grant. A. J. H. and O. K. F. gratefully acknowledge funding from the U.S. Dept. of F.nerg~ Office of Science, Basic Energy Sciences Program （No. DE-FG02-08ER15967）. The authors also thank Professor Huanting Wang from Monash University for further revising the manuscript.
文摘Shaping crystalline porous materials such as metal organic frameworks （MOFs） and zeolites into two-dimensional （2D） nanosheet forms is highly desirable for developing high-performance molecular sieving membranes. However, conventional exfoliation-deposition is complex and challenging for the large-scale fabrication of nanosheet MOF tubular membranes. Here, for the first time, we report a direct growth technique by ZnO self-conversion and ammonia assistance to fabricate zeolitic imidazolate framework （ZIF） membranes consisting of 2D nanosheets on porous hollow fiber substrates; the membranes are suitable for large-scale industrial gas separation processes. The proposed fabrication process for ZIF nanosheet membranes is based on the localized self-conversion of a pre-deposited thin layer of ZnO in a ligand solution containing ammonium hydroxide as a modulator. The resulting ZIF 2D nanosheet tubular membrane is highly oriented and only 50 nm in thickness. It exhibits excellent molecular sieving performance, with high H2 permeance and selectivity for H2/CO2 separation. This technique shows great promise in MOF nanosheet membrane fabrication for large-scale molecular sieving applications.
