The hydrogen absorption/desorption kinetic properties of MgH_(2)can be effectively enhanced by doping specific catalysts.In this work,MOFs-derived NiCu@C nanoparticles(~15 nm)with regular core-shell structure were suc...The hydrogen absorption/desorption kinetic properties of MgH_(2)can be effectively enhanced by doping specific catalysts.In this work,MOFs-derived NiCu@C nanoparticles(~15 nm)with regular core-shell structure were successfully prepared and introduced into MgH_(2)(denoted as MgH_(2)-NiCu@C).The onset and peak temperatures of hydrogen desorption of MgH_(2)-11 wt.%NiCu@C are 175.0℃and282.2℃,respectively.The apparent activation energy of dehydrogenated reaction is 77.2±4.5 kJ/mol for MgH_(2)-11 wt.%NiCu@C,which is lower than half of that of the as-milled MgH_(2).Moreover,MgH_(2)-11 wt.%NiCu@C displays great cyclic stability.The strengthening"hydrogen pumping"effect of reversible solid solutions Mg_(2)Ni(Cu)/Mg_(2)Ni(Cu)H_(4)is proposed to explain the remarkable improvement in hydrogen absorption/desorption kinetic properties of MgH_(2).This work offers a novel perspective for the design of bimetallic nanoparticles and beyond for application in hydrogen storage and other energy related fields.展开更多
CeZr, CeYZr, LaCeZr, LaCePrZr, LaCePrYZr, and LaCePr solid solutions were prepared via the coprecipitation method, and characterized by means of X-Ray Diffraction (XRD) and Brunauer-Emmett-Teller (BET) techniques....CeZr, CeYZr, LaCeZr, LaCePrZr, LaCePrYZr, and LaCePr solid solutions were prepared via the coprecipitation method, and characterized by means of X-Ray Diffraction (XRD) and Brunauer-Emmett-Teller (BET) techniques. The oxygen storage capacity (OSC) of the solid solutions was evaluated by the pulse technique and the catalytic activity was assessed using a 4-channel catalysis device. It was seen that the solid solutions presented cubic structure. The specific surface area and thermal stability could be enhanced by doping Y into the solid solutions. Doping a small amount of La had a positive effect on the thermal durability while doping a large amount of La decreased the specific surface area and the thermal stability. LaCePrZr and LaCePrYZr solid solutions synthesized using Baotou rare earth mineral residue enriched with LaCePr after Nd extraction presented a certain higher value in specific surface area and thermal stability, thereby enabling to be used as economic catalysts for automobile exhaust purification. Coating Al2O3 or SiO2 layer on the surface of ceria-zirconia solid solutions increased the specific surface area and thermal resistance.展开更多
Nanocrystals of Ce1-xMnxO2-δ(x=0.00,0.05,0.10,0.15,and 0.20) were synthesized by a hydrothermal reaction route.The solid solutions crystallized in a cubic fluorite structure with a particle size in the range of 11...Nanocrystals of Ce1-xMnxO2-δ(x=0.00,0.05,0.10,0.15,and 0.20) were synthesized by a hydrothermal reaction route.The solid solutions crystallized in a cubic fluorite structure with a particle size in the range of 11~15 nm.The incorporation of Mn ions in CeO2 resulted in a lattice volume reduction.Mn ions showed a mixed valence state of +2,+3 and +4 in CeO2 lattice.An obvious red-shift of the absorption threshold edge was observed from the UV-visible spectrum.Compared with the bulk CeO2,Ce1-xMnxO2-δ nanocrystals exhibited a lower releasing oxygen temperature as indicated by TPR technique.展开更多
A series of cadmium-calcium hydroxyapatite solid solutions was prepared by an aqueous precipitation method. By various means, the characterizations confirmed the formation of continuous solid solutions over all ranges...A series of cadmium-calcium hydroxyapatite solid solutions was prepared by an aqueous precipitation method. By various means, the characterizations confirmed the formation of continuous solid solutions over all ranges of Cd/(Cd+Ca) atomic ratio. In the results, both lattice parameters a and c display slight deviations from Vegard’s rule when the Cd/(Cd+Ca) atomic ratio is greater than 0.6. The particles change from smaller acicular to larger hexagonal columnar crystals as the Cd/(Cd+Ca) atomic ratio increases from 0-0.60 to 0.60-1.00. The area of the phosphate peak for symmetric P-O stretching decreases with the increase in Cd/(Cd+Ca) atomic ratio, and the peak disappears when the Cd/(Cd+Ca) atomic ratio is greater than 0.6; the two phosphate peaks of P-O stretching gradually merge together for the Cd/(Cd+Ca) atomic ratio near 0.60. These variations can be explained by a slight tendency of larger Cd ions to occupy M(2) sites and smaller Ca ions to prefer M(1) sites in the structure.展开更多
Samples of Ag<sub>8</sub>Ge<sub>1-x</sub>Mn<sub>x</sub>Te<sub>6</sub> solid solutions with different manganese content (x = 0, 0.05, 0.1, 0.2) were prepared by fusing an...Samples of Ag<sub>8</sub>Ge<sub>1-x</sub>Mn<sub>x</sub>Te<sub>6</sub> solid solutions with different manganese content (x = 0, 0.05, 0.1, 0.2) were prepared by fusing and further pressing their powders under the pressure of 0.6 GPa. In addition of Mn atoms to the Ag<sub>8</sub>GeTe<sub>6</sub> compound leads to compression of their lattice. All p-type samples acquire a high resistance below the transition at temperatures of 180 - 220 K. The electrical conductivity of all compositions in the range of 220 - 300 K increases due to hopping mechanism, and at temperatures T > 320 K, a semiconductor characteristic is observed. By studying impedance spectra of samples, it was established that at 80 K solid solutions behave like a homogeneous dielectric material. At high temperatures and frequencies of an external electric field, a significant role of grain boundaries in conductivity was revealed. The dielectric anomaly occurring at low frequencies is also associated with an effect that manifests itself in the grain boundary.展开更多
Nanosized Ce^1-x)(Nd^0.5)Eu^0.5))xO^2-δ) solid solutions(x = 0.00-0.20) were synthesized by means of hydrothermal method.Then the solid solutions were ball milled with Mg2Ni and Ni powders for 20 h to get the...Nanosized Ce^1-x)(Nd^0.5)Eu^0.5))xO^2-δ) solid solutions(x = 0.00-0.20) were synthesized by means of hydrothermal method.Then the solid solutions were ball milled with Mg2Ni and Ni powders for 20 h to get the Mg2Ni–Ni–5 mol% Ce^1-x)(Nd^0.5)Eu^0.5))xO^2-δ) composites.The structures and spectrum characteristics of the Ce^1-x)(Nd^0.5)Eu^0.5))xO^2-δ) solid solutions catalysts were analyzed systemically.XRD results showed that the doped samples exhibited single phase of CeO2 fluorite structure.The cell parameters and cell volumes were increased with increasing the doped content.Raman spectrum revealed that the peak position of F^2g mode shift to higher wavenumbers and the peak corresponding to oxygen vacancies were observed distinctly for the doped samples.UV-Vis technique indicated that the absorption peaks of Eu^3+ and Nd^3+ ions appeared; the bandgap energy was decreased linearly.The electrochemical and kinetic properties of the Mg2Ni–Ni–5 mol% Ce1-x(Nd0.5Eu0.5xO2-δ composites were measured.The maximum discharge capacity was increased from 722.3 mA h/g for x = 0.00 to 819.7 mA h/g for x = 0.16,and the cycle stability S20 increased from 25.0%(x = 0.00) to 42.2%(x = 0.20).The kinetic measurement proved that the catalytic activity of composite surfaces and the hydrogen diffusion rate were improved for the composites with doped catalysts,especially for the composites with x = 0.16 and x = 0.20.The catalysis mechanism was analyzed from the point of microstructure and spectrum features of the Ce1-x(Nd0.5Eu0.5)xO2-δ solid solutions.展开更多
The Ce_xTh_(1-x)O_2 solid solutions were prepared by citrate sol-gel method,and their structure and reduction properties were studied. XRD shows that solid solution with cubicphase formed in all the solid solutions (x...The Ce_xTh_(1-x)O_2 solid solutions were prepared by citrate sol-gel method,and their structure and reduction properties were studied. XRD shows that solid solution with cubicphase formed in all the solid solutions (x = 0.2, 0.5, 0.8) Ce_xTh_(1-x)O_2. Raman spectrum showsthat Ce-Th complex oxides can promote the formation of oxygen vacancies. Two reduction peaks appearin the TPR profiles of Ce_xTh_(1-x)O_2 solid solution. The a peak is attributed to the reduction ofCe^(4+) on the surface, and the β peak is attributed to the reduction of bulk CeO_2. Theincorporation of Th atom into CeO_2 improves the reduction of CeO_2. Ce_xTh_(1-x)O_2 mixed oxidesare promising materials for oxygen vacancies produced, as well as catalysts for many reactionsinvolved oxygen, such as the catalysts for three-way reactions for reducing the releasing pollutantsor combustion of VOCs.展开更多
The electronic structure and thermoelectric(TE) properties of Mg2GexSn1-x(x = 0.25, 0.50, 0.75) solid solutions are investigated by first-principles calculations and semi-classical Boltzmann theory. The special qu...The electronic structure and thermoelectric(TE) properties of Mg2GexSn1-x(x = 0.25, 0.50, 0.75) solid solutions are investigated by first-principles calculations and semi-classical Boltzmann theory. The special quasi-random structure(SQS) is used to model the solid solutions, which can produce reasonable band gaps with respect to experimental results.The n-type solid solutions have an excellent thermoelectric performance with maximum zT values exceeding 2.0, where the combination of low lattice thermal conductivity and high power factor(PF) plays an important role. These values are higher than those of pure Mg2Sn and Mg2Ge. The p-type solid solutions are inferior to the n-type ones, mainly due to the much lower PF. The maximum zT value of 0.62 is predicted for p-type Mg2Ge(0.25)Sn(0.75) at 800K. The results suggest that the n-type Mg2GexSn1-x solid solutions are promising mid-temperature TE materials.展开更多
For the pursuit of high energy supercapacitors,the development of high performance pseudocapacitance or battery-type negative electrode material is urgently needed to make up for the capacity shortage of commercial el...For the pursuit of high energy supercapacitors,the development of high performance pseudocapacitance or battery-type negative electrode material is urgently needed to make up for the capacity shortage of commercial electric double layer capacitor(EDLC)type materials.Herein,a porous and defect-rich Fe_(x)Bi_(2-x)S_(3) solid solution structure is firstly constructed by employing Fe-doped Bi_(2)O_(2)CO_(3) porous nanosheets as a precursor,which presents dramatically increased energy storage performance than Bi_(2)S_(3) and FeS_(2) phase.For the optimized Fe_(x)Bi_(2-x)S_(3) solid solution(FeBiS-60%),the Fe solute is free and random dispersed in Bi_(2)S_(3) framework,which can effectively modulate the electronic structure of Bi element and introduce rich-defect due to the existence of Fe(II).Meanwhile,the FeBiS-60%,constructed by pore nanosheets that are assembled by self-supported basic nanorod units,presents rich mesoporous channels for fast mass transfer and abundant active sites for promoting capacity performance.Therefore,a high capacitance of 832.8 F·g^(-1) at a current density of 1 A·g^(-1) is achieved by the FeBiS-60%electrode.Furthermore,a fabricated Ni3S_(2)@Co_(3)S_(4)(NCS)//FeBiS-60%hybrid supercapacitor device delivers an outstanding energy density of 85.33 Wh·kg^(-1) at the power density of 0.799 kW·kg^(-1),and ultra-long lifespan of remaining 86.7%initial capacitance after 8700 cycles.展开更多
Multi-phase ceramics based on ZrB_(2),TiB_(2) and doped with CrB_(2) and SiC were prepared by powder metallurgy and hot pressing to explore the possibility of obtaining multi-scale microstructures by super-saturation ...Multi-phase ceramics based on ZrB_(2),TiB_(2) and doped with CrB_(2) and SiC were prepared by powder metallurgy and hot pressing to explore the possibility of obtaining multi-scale microstructures by super-saturation of complex(Zr,Ti,Cr)B_(2) solid solutions.Core-shell structures formed in TiB_(2) grains,whereas ZrB_(2) appeared to form a homogeneous solid solution with the other metals.Precipitation of nano-inclusions within both micron-sized borides was assessed by transmission electron microscopy and thermodynamics elucidated the preferential formation of boride inclusions due to the specific sintering atmosphere.In addition,atomic size factors explicated the precipitation of CrB_(2) nano-particles into ZrB_(2)-rich grains and of ZrB_(2) nano-particles into TiB_(2)-rich grains.The hardness of the constituent phases measured by nanoindentation ranged from 36 to 43 GPa.展开更多
Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-...Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-speed rail contact wires,electronic component connectors,and other devices.Overcoming the contradiction between low alloying and high performance is an important challenge in the development of solid solution-strengthened copper alloys.Taking the typical solid solution-strengthened alloy Cu-4Zn-1Sn as the research object,we proposed using the element In to replace Zn and Sn to achieve low alloying in this work.Two new alloys,Cu-1.5Zn-1Sn-0.4In and Cu-1.5Zn-0.9Sn-0.6In,were designed and prepared.The total weight percentage content of alloying elements decreased by 43%and 41%,respectively,while the product of ultimate tensile strength(UTS)and electrical conductivity(EC)of the annealed state increased by 14%and 15%.After cold rolling with a 90%reduction,the UTS of the two new alloys reached 576 and 627MPa,respectively,the EC was 44.9%IACS and 42.0%IACS,and the product of UTS and EC(UTS×EC)was 97%and 99%higher than that of the annealed state alloy.The dislocations proliferated greatly in cold-rolled alloys,and the strengthening effects of dislocations reached 332 and 356 MPa,respectively,which is the main reason for the considerable improvement in mechanical properties.展开更多
Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and on...Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and only a limited candidates have been reported so far.In this work,we found for the first time that a continuous solid solution,Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2)(0≤α≤1,could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P_(2)O_(7) unchanged.In particular,a novel off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)is thus proposed,and its structure,energy storage mechanism,and electrochemical performance are extensively investigated to unveil the structure–function relationship.The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mAh g^(−1),a working voltage of 2.9 V(vs.Na^(+)/Na),the retention of 89.2%of the initial capacity after 500 cycles,and enhanced rate capability of 51 mAh g^(−1)at a current density of 1600 mA g^(−1).This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2),offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs.展开更多
In this study, a facile alcoholysis method was developed to synthesize BiOCIxBr1_x nanoplates at room temperature and atmospheric pressure. In this route, strong acid or alkaline environment was absolutely avoided to ...In this study, a facile alcoholysis method was developed to synthesize BiOCIxBr1_x nanoplates at room temperature and atmospheric pressure. In this route, strong acid or alkaline environment was absolutely avoided to realize the high exposure of {001} crystal facets. The regular changes in XRD peaks and cell parameters as a function of the Br content strongly declared that the obtained BiOCIxBrl_x products belonged to a group of solid solutions. The 2D nanosheets with in-plane wrinkles were clearly observed in TEM images. Interestingly, as the Br content increased, band gaps of BiOCIxBr1-x solid solutions gradually decreased. The photocatalytic degradation of RhB under simulated sunlight irradiation indicated that BiOCI0.sBr0.5 had the best photocatalytic activity. From the viewpoint of crystal chemistry, the photocatalytic activity of BiOCIxBr1-x solid solutions was closely related with the exposure amount of {001} facets, interlayer spacing of (001) plane and energy-level position of valence band.展开更多
In recent years,industries in the fields of petrochemical,automotive,and aerospace have expressed their interest in utilizing piezoelectric actuators for high-temperature(HT)operations at the temperature above 150℃.H...In recent years,industries in the fields of petrochemical,automotive,and aerospace have expressed their interest in utilizing piezoelectric actuators for high-temperature(HT)operations at the temperature above 150℃.HT piezoelectric ceramics(1x)BiScO_(3-x)PbTiO_(3)(BS-PT)are considered as one of the most competitive piezoelectric actuation materials used in the harsh environment because of its high Curie temperature(T_(C)=450℃)as well as high piezoelectric coefficient(d_(33)=460 pC/N)in the MPB composition.This paper summarized the recent progress in HT piezoelectric ceramics and actuators based on BS-PT solid solutions.The properties of BS-PT piezoelectric ceramics and actuators,including driving mechanisms,actuation performances and their applications in HT environment were also discussed.展开更多
The influence of the B-site ion substitutions in(1-x)(Bi_(1/2)Na_(1/2))TiO_(3)–xBaTiO_(3)system of solid solutions on the relative stability of the antiferroelectric(AFE)and ferroelectric(FE)phases has been studied.T...The influence of the B-site ion substitutions in(1-x)(Bi_(1/2)Na_(1/2))TiO_(3)–xBaTiO_(3)system of solid solutions on the relative stability of the antiferroelectric(AFE)and ferroelectric(FE)phases has been studied.The ions of zirconium,tin,and(In_(0.5)Nb_(0.5)),(Fe_(0.5)Nb_(0.5)),(Al_(0.5)V_(0.5))ion complexes have been used as substituting elements.An increase in the concentration of the substituting ion results in a near linear variation in the size of the crystal lattice cell.Along with the cell size variation,a change in the relative stability of the AFE and FE phases takes place according to the changes of the tolerance factor of the solid solution.An increase in the tolerance factor leads to the increase in the temperature of the FE–AFE phase transition,and vice versa.Obtained results indicate the way for raising the temperature of the FE–AFE phase transition in(Bi_(1/2)Na_(1/2))TiO_(3)-based solid solutions.展开更多
We explored such issues as the formation mechanism,structure and propriety of the solid solutions of anthracene(ANT)-phenanthrene(PHE).Solution crystallization and solid-state grinding were employed to prepare solid s...We explored such issues as the formation mechanism,structure and propriety of the solid solutions of anthracene(ANT)-phenanthrene(PHE).Solution crystallization and solid-state grinding were employed to prepare solid solutions under different conditions.The thermal behavior and PXRD scanning results revealed the formation of discontinuous solid solutions,whose melting points and crystal lattices varied linearly with mixed ratio.Combing with Materials Studio,the formation possibility of solid solutions were investigated by evaluating the change of the energy.The crystal morphology of the solid solutions have a positive correlation with the change of the major part.Finally,the solution crystallization process of solid solution were studied using the population balance model.展开更多
The aerobic,selective oxidation of hydrocarbons via C-H bond activation is still a challenge.This work shows the achievement of the room temperature visible light driven photocatalytic activation of benzylic C-H bonds...The aerobic,selective oxidation of hydrocarbons via C-H bond activation is still a challenge.This work shows the achievement of the room temperature visible light driven photocatalytic activation of benzylic C-H bonds with N-hydroxysuccinimide over BiOBr_(x)I_(1-x)(0≤x≤1)solid solutions,whose valance bands were engineered through varying the ratio of bromide to iodide.The optimal BiOBr0.85I0.15 catalyst exhibited over 98%conversion ratio of ethylbenzene,which was about 3.9 and 8.9 times that of pure BiOBr and BiOI,respectively.The excellent photocatalytic activity of BiOBr0.85I0.15 solid solution can be ascribed to the orbital hybridization of the valence band containing both Br 4p and I 5p orbitals,which could promote photo-induced charge carrier separation and improve the generation of singlet oxygen.This work shed some light on the rational design of photocatalysts for targeted organic transformation.展开更多
Solid solutions(SS)of 3-and 4-component systems based on lead titanate-zirconate were prepared by the method of solid-phase reactions and uniaxial hot pressing.The dependences of the relative permittivity of polarized...Solid solutions(SS)of 3-and 4-component systems based on lead titanate-zirconate were prepared by the method of solid-phase reactions and uniaxial hot pressing.The dependences of the relative permittivity of polarized samples on the electronegativity(EN)of their constituent cations have been studied.The ferro-hardness of the SS(the stability of the domain structure to external influences)is shown to be directly dependent on the EN of elements B in the corresponding oxidation states,i.e.,the degree of covalence of the B-O bond.The deviation from this dependence in SS with Ni and Cd is explained by their individual features,which result in changes in the degree of bond covalence in both cationic sublattices.The conducted crystal-chemical analysis made it possible to choose promising SS when creating ferroelectric materials,including textured piezoelectric ceramic materials for piezoelectric transducers for various purposes:Piezotransformers,piezoelectric motors,ultrasonic emitters,filter devices,ultrasonic flaw detectors,accelerometers,etc.展开更多
Recently,large phase-change magnetoelectric response has been anticipated by a first-principles investigation of phases in the BiFeO_(3)–BiCoO_(3)perovskite binary system,associated with the existence of a discontinu...Recently,large phase-change magnetoelectric response has been anticipated by a first-principles investigation of phases in the BiFeO_(3)–BiCoO_(3)perovskite binary system,associated with the existence of a discontinuous morphotropic phase boundary(MPB)between multiferroic polymorphs of rhombohedral and tetragonal symmetries.This might be a general property of multiferroic phase instabilities,and a novel promising approach for room temperature magnetoelectricity.We review here our current inves-tigations on the identification and study of additional material systems,alternative to BiFeO_(3)–BiCoO_(3)that has only been obtained by high pressure synthesis.Three systems,whose phase diagrams were,in principle,liable to show multiferroic MPBs have been addressed:the BiMnO_(3)–PbTiO_(3)and BiFeO_(3)–PbTiO_(3)binary systems,and the BiFeO_(3)–BiMnO_(3)–PbTiO_(3)ternary one.A compre-hensive study of multiferroism across different solid solutions was carried out based on electrical and magnetic characterizations,complemented with mechanical and electromechanical measurements.An in-depth structural analysis was also accomplished when necessary.展开更多
Some of the known binary ABO_(3)perovskites with ferro-(FE)or antiferroelectric(AFE)at T_(C)and different magnetic phase tran-sitions(PT):ferro-and antiferromagnetic at T_(N)and also some of their solid solutions are ...Some of the known binary ABO_(3)perovskites with ferro-(FE)or antiferroelectric(AFE)at T_(C)and different magnetic phase tran-sitions(PT):ferro-and antiferromagnetic at T_(N)and also some of their solid solutions are considered.Some correlations between their FE or AFE and/or magnetic PTs temperatures,on the one hand,and their interatomic bond A-O strains,on the other hand,have been constructed.It is shown that in the plotted diagrams these temperatures change with a change inδAO values as follows:classical FEs are followed by multiferroics,starting with BiFeO_(3)and ending with YVO_(3),followed by classical AFEs.At the same time,the temperatures T_(C)and T_(N)experience maxima at the corresponding points for BiFeO_(3),then quickly decrease,and the difference between them,T_(C)-T_(N),basically also decreases,slightly increasing along the way to the point EuTiO_(3).which made it possible to systematize these T_(C)and T_(N).展开更多
基金supported by the National Natural Science Foundation of China(52071177,52171214)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_1112,KYCX21_1107)+1 种基金Six Talent Peaks Project in Jiangsu Province(2018,XNY-020)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。
文摘The hydrogen absorption/desorption kinetic properties of MgH_(2)can be effectively enhanced by doping specific catalysts.In this work,MOFs-derived NiCu@C nanoparticles(~15 nm)with regular core-shell structure were successfully prepared and introduced into MgH_(2)(denoted as MgH_(2)-NiCu@C).The onset and peak temperatures of hydrogen desorption of MgH_(2)-11 wt.%NiCu@C are 175.0℃and282.2℃,respectively.The apparent activation energy of dehydrogenated reaction is 77.2±4.5 kJ/mol for MgH_(2)-11 wt.%NiCu@C,which is lower than half of that of the as-milled MgH_(2).Moreover,MgH_(2)-11 wt.%NiCu@C displays great cyclic stability.The strengthening"hydrogen pumping"effect of reversible solid solutions Mg_(2)Ni(Cu)/Mg_(2)Ni(Cu)H_(4)is proposed to explain the remarkable improvement in hydrogen absorption/desorption kinetic properties of MgH_(2).This work offers a novel perspective for the design of bimetallic nanoparticles and beyond for application in hydrogen storage and other energy related fields.
基金the National Key Basic Research Program (NKBRP 20047CCA03900)the National Natural Science Foundation of China (50662002)
文摘CeZr, CeYZr, LaCeZr, LaCePrZr, LaCePrYZr, and LaCePr solid solutions were prepared via the coprecipitation method, and characterized by means of X-Ray Diffraction (XRD) and Brunauer-Emmett-Teller (BET) techniques. The oxygen storage capacity (OSC) of the solid solutions was evaluated by the pulse technique and the catalytic activity was assessed using a 4-channel catalysis device. It was seen that the solid solutions presented cubic structure. The specific surface area and thermal stability could be enhanced by doping Y into the solid solutions. Doping a small amount of La had a positive effect on the thermal durability while doping a large amount of La decreased the specific surface area and the thermal stability. LaCePrZr and LaCePrYZr solid solutions synthesized using Baotou rare earth mineral residue enriched with LaCePr after Nd extraction presented a certain higher value in specific surface area and thermal stability, thereby enabling to be used as economic catalysts for automobile exhaust purification. Coating Al2O3 or SiO2 layer on the surface of ceria-zirconia solid solutions increased the specific surface area and thermal resistance.
基金Supported by NNSFC (Nos 20671092, 20773132, 20771101)National Basic Research Program of China (No 2007BAE08B01, 2009 CB613306)
文摘Nanocrystals of Ce1-xMnxO2-δ(x=0.00,0.05,0.10,0.15,and 0.20) were synthesized by a hydrothermal reaction route.The solid solutions crystallized in a cubic fluorite structure with a particle size in the range of 11~15 nm.The incorporation of Mn ions in CeO2 resulted in a lattice volume reduction.Mn ions showed a mixed valence state of +2,+3 and +4 in CeO2 lattice.An obvious red-shift of the absorption threshold edge was observed from the UV-visible spectrum.Compared with the bulk CeO2,Ce1-xMnxO2-δ nanocrystals exhibited a lower releasing oxygen temperature as indicated by TPR technique.
基金financially supported by the National Natural Science Foundation of China(No.41263009)the Guangxi Science and Technology Development Project(No.GuiKeZhong 1298002-3)the National Natural Science Foundation of Guangxi of China(No.2012GXNSFDA053022)
文摘A series of cadmium-calcium hydroxyapatite solid solutions was prepared by an aqueous precipitation method. By various means, the characterizations confirmed the formation of continuous solid solutions over all ranges of Cd/(Cd+Ca) atomic ratio. In the results, both lattice parameters a and c display slight deviations from Vegard’s rule when the Cd/(Cd+Ca) atomic ratio is greater than 0.6. The particles change from smaller acicular to larger hexagonal columnar crystals as the Cd/(Cd+Ca) atomic ratio increases from 0-0.60 to 0.60-1.00. The area of the phosphate peak for symmetric P-O stretching decreases with the increase in Cd/(Cd+Ca) atomic ratio, and the peak disappears when the Cd/(Cd+Ca) atomic ratio is greater than 0.6; the two phosphate peaks of P-O stretching gradually merge together for the Cd/(Cd+Ca) atomic ratio near 0.60. These variations can be explained by a slight tendency of larger Cd ions to occupy M(2) sites and smaller Ca ions to prefer M(1) sites in the structure.
文摘Samples of Ag<sub>8</sub>Ge<sub>1-x</sub>Mn<sub>x</sub>Te<sub>6</sub> solid solutions with different manganese content (x = 0, 0.05, 0.1, 0.2) were prepared by fusing and further pressing their powders under the pressure of 0.6 GPa. In addition of Mn atoms to the Ag<sub>8</sub>GeTe<sub>6</sub> compound leads to compression of their lattice. All p-type samples acquire a high resistance below the transition at temperatures of 180 - 220 K. The electrical conductivity of all compositions in the range of 220 - 300 K increases due to hopping mechanism, and at temperatures T > 320 K, a semiconductor characteristic is observed. By studying impedance spectra of samples, it was established that at 80 K solid solutions behave like a homogeneous dielectric material. At high temperatures and frequencies of an external electric field, a significant role of grain boundaries in conductivity was revealed. The dielectric anomaly occurring at low frequencies is also associated with an effect that manifests itself in the grain boundary.
基金supported by the National Natural Science Foundations of China(51501095,51371094)the Natural Science Foundation of Inner Mongolia(2017MS(LH)0516)
文摘Nanosized Ce^1-x)(Nd^0.5)Eu^0.5))xO^2-δ) solid solutions(x = 0.00-0.20) were synthesized by means of hydrothermal method.Then the solid solutions were ball milled with Mg2Ni and Ni powders for 20 h to get the Mg2Ni–Ni–5 mol% Ce^1-x)(Nd^0.5)Eu^0.5))xO^2-δ) composites.The structures and spectrum characteristics of the Ce^1-x)(Nd^0.5)Eu^0.5))xO^2-δ) solid solutions catalysts were analyzed systemically.XRD results showed that the doped samples exhibited single phase of CeO2 fluorite structure.The cell parameters and cell volumes were increased with increasing the doped content.Raman spectrum revealed that the peak position of F^2g mode shift to higher wavenumbers and the peak corresponding to oxygen vacancies were observed distinctly for the doped samples.UV-Vis technique indicated that the absorption peaks of Eu^3+ and Nd^3+ ions appeared; the bandgap energy was decreased linearly.The electrochemical and kinetic properties of the Mg2Ni–Ni–5 mol% Ce1-x(Nd0.5Eu0.5xO2-δ composites were measured.The maximum discharge capacity was increased from 722.3 mA h/g for x = 0.00 to 819.7 mA h/g for x = 0.16,and the cycle stability S20 increased from 25.0%(x = 0.00) to 42.2%(x = 0.20).The kinetic measurement proved that the catalytic activity of composite surfaces and the hydrogen diffusion rate were improved for the composites with doped catalysts,especially for the composites with x = 0.16 and x = 0.20.The catalysis mechanism was analyzed from the point of microstructure and spectrum features of the Ce1-x(Nd0.5Eu0.5)xO2-δ solid solutions.
文摘The Ce_xTh_(1-x)O_2 solid solutions were prepared by citrate sol-gel method,and their structure and reduction properties were studied. XRD shows that solid solution with cubicphase formed in all the solid solutions (x = 0.2, 0.5, 0.8) Ce_xTh_(1-x)O_2. Raman spectrum showsthat Ce-Th complex oxides can promote the formation of oxygen vacancies. Two reduction peaks appearin the TPR profiles of Ce_xTh_(1-x)O_2 solid solution. The a peak is attributed to the reduction ofCe^(4+) on the surface, and the β peak is attributed to the reduction of bulk CeO_2. Theincorporation of Th atom into CeO_2 improves the reduction of CeO_2. Ce_xTh_(1-x)O_2 mixed oxidesare promising materials for oxygen vacancies produced, as well as catalysts for many reactionsinvolved oxygen, such as the catalysts for three-way reactions for reducing the releasing pollutantsor combustion of VOCs.
基金supported by the National Natural Science Foundation of China(Grant No.11647010)the Foundation from the Higher Education and High-quality and World-class Universities(Grant No.PY201611)
文摘The electronic structure and thermoelectric(TE) properties of Mg2GexSn1-x(x = 0.25, 0.50, 0.75) solid solutions are investigated by first-principles calculations and semi-classical Boltzmann theory. The special quasi-random structure(SQS) is used to model the solid solutions, which can produce reasonable band gaps with respect to experimental results.The n-type solid solutions have an excellent thermoelectric performance with maximum zT values exceeding 2.0, where the combination of low lattice thermal conductivity and high power factor(PF) plays an important role. These values are higher than those of pure Mg2Sn and Mg2Ge. The p-type solid solutions are inferior to the n-type ones, mainly due to the much lower PF. The maximum zT value of 0.62 is predicted for p-type Mg2Ge(0.25)Sn(0.75) at 800K. The results suggest that the n-type Mg2GexSn1-x solid solutions are promising mid-temperature TE materials.
基金support from the National Natural Science Foundation of China(Nos.52272222,52072197)Outstanding Youth Foundation of Shandong Province,China(No.ZR2019JQ14)+4 种基金University Youth Innovation Team of Shandong Province(Nos.2019KJC004,202201010318)the Natural Science Foundation of Shandong Province,China(No.ZR2021MB061)Major Scientific and Technological Innovation Project(No.2019JZZY020405)Taishan Scholar Young Talent Program(No.tsqn201909114)Major Basic Research Program of Natural Science Foundation of Shandong Province under Grant(No.ZR2020ZD09).
文摘For the pursuit of high energy supercapacitors,the development of high performance pseudocapacitance or battery-type negative electrode material is urgently needed to make up for the capacity shortage of commercial electric double layer capacitor(EDLC)type materials.Herein,a porous and defect-rich Fe_(x)Bi_(2-x)S_(3) solid solution structure is firstly constructed by employing Fe-doped Bi_(2)O_(2)CO_(3) porous nanosheets as a precursor,which presents dramatically increased energy storage performance than Bi_(2)S_(3) and FeS_(2) phase.For the optimized Fe_(x)Bi_(2-x)S_(3) solid solution(FeBiS-60%),the Fe solute is free and random dispersed in Bi_(2)S_(3) framework,which can effectively modulate the electronic structure of Bi element and introduce rich-defect due to the existence of Fe(II).Meanwhile,the FeBiS-60%,constructed by pore nanosheets that are assembled by self-supported basic nanorod units,presents rich mesoporous channels for fast mass transfer and abundant active sites for promoting capacity performance.Therefore,a high capacitance of 832.8 F·g^(-1) at a current density of 1 A·g^(-1) is achieved by the FeBiS-60%electrode.Furthermore,a fabricated Ni3S_(2)@Co_(3)S_(4)(NCS)//FeBiS-60%hybrid supercapacitor device delivers an outstanding energy density of 85.33 Wh·kg^(-1) at the power density of 0.799 kW·kg^(-1),and ultra-long lifespan of remaining 86.7%initial capacitance after 8700 cycles.
基金sponsored by the NATO Science for Peace and Security Programme under grant MYP-G5767 (SUSPENCE)by the US AFOSR through the grant no.FA9550-21-1-0399 (NACREOUS)with Dr.Ming-Jen Pan as contract monitor+1 种基金supply of laboratory facilities.NG acknowledges the support received by JECS Trust for a mobility grant (ref.2020240)of three months at UPC,SpainNanoindentation tests were funded through The Spanish Ministry of Science,Innovation and Universities through grant PGC-2018-096855-B-C41.S.Guicciardi (CNR-ISMAR)is acknowledged for discussion on nanoindentation.
文摘Multi-phase ceramics based on ZrB_(2),TiB_(2) and doped with CrB_(2) and SiC were prepared by powder metallurgy and hot pressing to explore the possibility of obtaining multi-scale microstructures by super-saturation of complex(Zr,Ti,Cr)B_(2) solid solutions.Core-shell structures formed in TiB_(2) grains,whereas ZrB_(2) appeared to form a homogeneous solid solution with the other metals.Precipitation of nano-inclusions within both micron-sized borides was assessed by transmission electron microscopy and thermodynamics elucidated the preferential formation of boride inclusions due to the specific sintering atmosphere.In addition,atomic size factors explicated the precipitation of CrB_(2) nano-particles into ZrB_(2)-rich grains and of ZrB_(2) nano-particles into TiB_(2)-rich grains.The hardness of the constituent phases measured by nanoindentation ranged from 36 to 43 GPa.
基金financially supported by the National Key Research and Development Program of China(No.2021YFB3803101)the National Natural Science Foundation of China(Nos.52022011,51974028,and 52090041)+1 种基金the Xiaomi Young Scholars ProgramChina National Postdoctoral Program for Innovative Talents(No.BX20230042)。
文摘Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-speed rail contact wires,electronic component connectors,and other devices.Overcoming the contradiction between low alloying and high performance is an important challenge in the development of solid solution-strengthened copper alloys.Taking the typical solid solution-strengthened alloy Cu-4Zn-1Sn as the research object,we proposed using the element In to replace Zn and Sn to achieve low alloying in this work.Two new alloys,Cu-1.5Zn-1Sn-0.4In and Cu-1.5Zn-0.9Sn-0.6In,were designed and prepared.The total weight percentage content of alloying elements decreased by 43%and 41%,respectively,while the product of ultimate tensile strength(UTS)and electrical conductivity(EC)of the annealed state increased by 14%and 15%.After cold rolling with a 90%reduction,the UTS of the two new alloys reached 576 and 627MPa,respectively,the EC was 44.9%IACS and 42.0%IACS,and the product of UTS and EC(UTS×EC)was 97%and 99%higher than that of the annealed state alloy.The dislocations proliferated greatly in cold-rolled alloys,and the strengthening effects of dislocations reached 332 and 356 MPa,respectively,which is the main reason for the considerable improvement in mechanical properties.
基金National Natural Science Foundation of China,Grant/Award Numbers:21972108,U20A20249,U22A20438Changzhou Science and Technology Bureau,Grant/Award Number:CM20223017Innovation and Technology Commission(ITC)of Hong Kong,The Innovation&Technology Fund(ITF)with Project No.ITS/126/21。
文摘Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and only a limited candidates have been reported so far.In this work,we found for the first time that a continuous solid solution,Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2)(0≤α≤1,could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P_(2)O_(7) unchanged.In particular,a novel off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)is thus proposed,and its structure,energy storage mechanism,and electrochemical performance are extensively investigated to unveil the structure–function relationship.The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mAh g^(−1),a working voltage of 2.9 V(vs.Na^(+)/Na),the retention of 89.2%of the initial capacity after 500 cycles,and enhanced rate capability of 51 mAh g^(−1)at a current density of 1600 mA g^(−1).This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2),offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs.
文摘In this study, a facile alcoholysis method was developed to synthesize BiOCIxBr1_x nanoplates at room temperature and atmospheric pressure. In this route, strong acid or alkaline environment was absolutely avoided to realize the high exposure of {001} crystal facets. The regular changes in XRD peaks and cell parameters as a function of the Br content strongly declared that the obtained BiOCIxBrl_x products belonged to a group of solid solutions. The 2D nanosheets with in-plane wrinkles were clearly observed in TEM images. Interestingly, as the Br content increased, band gaps of BiOCIxBr1-x solid solutions gradually decreased. The photocatalytic degradation of RhB under simulated sunlight irradiation indicated that BiOCI0.sBr0.5 had the best photocatalytic activity. From the viewpoint of crystal chemistry, the photocatalytic activity of BiOCIxBr1-x solid solutions was closely related with the exposure amount of {001} facets, interlayer spacing of (001) plane and energy-level position of valence band.
基金supported by the National Natural Science Foundation of China(Grant Nos.51132001,51072003,11090331,51302163)the Innovational Foundation of Shanghai University(Grant No.K.10-0110-13-009).
文摘In recent years,industries in the fields of petrochemical,automotive,and aerospace have expressed their interest in utilizing piezoelectric actuators for high-temperature(HT)operations at the temperature above 150℃.HT piezoelectric ceramics(1x)BiScO_(3-x)PbTiO_(3)(BS-PT)are considered as one of the most competitive piezoelectric actuation materials used in the harsh environment because of its high Curie temperature(T_(C)=450℃)as well as high piezoelectric coefficient(d_(33)=460 pC/N)in the MPB composition.This paper summarized the recent progress in HT piezoelectric ceramics and actuators based on BS-PT solid solutions.The properties of BS-PT piezoelectric ceramics and actuators,including driving mechanisms,actuation performances and their applications in HT environment were also discussed.
文摘The influence of the B-site ion substitutions in(1-x)(Bi_(1/2)Na_(1/2))TiO_(3)–xBaTiO_(3)system of solid solutions on the relative stability of the antiferroelectric(AFE)and ferroelectric(FE)phases has been studied.The ions of zirconium,tin,and(In_(0.5)Nb_(0.5)),(Fe_(0.5)Nb_(0.5)),(Al_(0.5)V_(0.5))ion complexes have been used as substituting elements.An increase in the concentration of the substituting ion results in a near linear variation in the size of the crystal lattice cell.Along with the cell size variation,a change in the relative stability of the AFE and FE phases takes place according to the changes of the tolerance factor of the solid solution.An increase in the tolerance factor leads to the increase in the temperature of the FE–AFE phase transition,and vice versa.Obtained results indicate the way for raising the temperature of the FE–AFE phase transition in(Bi_(1/2)Na_(1/2))TiO_(3)-based solid solutions.
文摘We explored such issues as the formation mechanism,structure and propriety of the solid solutions of anthracene(ANT)-phenanthrene(PHE).Solution crystallization and solid-state grinding were employed to prepare solid solutions under different conditions.The thermal behavior and PXRD scanning results revealed the formation of discontinuous solid solutions,whose melting points and crystal lattices varied linearly with mixed ratio.Combing with Materials Studio,the formation possibility of solid solutions were investigated by evaluating the change of the energy.The crystal morphology of the solid solutions have a positive correlation with the change of the major part.Finally,the solution crystallization process of solid solution were studied using the population balance model.
基金supported by the National Natural Science Foundation of China(No.21671176)Post-doctoral Foundation of Henan。
文摘The aerobic,selective oxidation of hydrocarbons via C-H bond activation is still a challenge.This work shows the achievement of the room temperature visible light driven photocatalytic activation of benzylic C-H bonds with N-hydroxysuccinimide over BiOBr_(x)I_(1-x)(0≤x≤1)solid solutions,whose valance bands were engineered through varying the ratio of bromide to iodide.The optimal BiOBr0.85I0.15 catalyst exhibited over 98%conversion ratio of ethylbenzene,which was about 3.9 and 8.9 times that of pure BiOBr and BiOI,respectively.The excellent photocatalytic activity of BiOBr0.85I0.15 solid solution can be ascribed to the orbital hybridization of the valence band containing both Br 4p and I 5p orbitals,which could promote photo-induced charge carrier separation and improve the generation of singlet oxygen.This work shed some light on the rational design of photocatalysts for targeted organic transformation.
基金This study was financially supported by the Ministry of Science and Higher Education of the Russian Federation(State task in the field of scientific activity,scientific project No.(0852-2020-0032)/(BAZ0110/20-3-07IF))This report is presented at the 10th Anniversary International Conference on“Physics and Mechanics of New Materials and Their Applications”(PHENMA 2021),Divnomorsk,Russia,May 23-27,2022.
文摘Solid solutions(SS)of 3-and 4-component systems based on lead titanate-zirconate were prepared by the method of solid-phase reactions and uniaxial hot pressing.The dependences of the relative permittivity of polarized samples on the electronegativity(EN)of their constituent cations have been studied.The ferro-hardness of the SS(the stability of the domain structure to external influences)is shown to be directly dependent on the EN of elements B in the corresponding oxidation states,i.e.,the degree of covalence of the B-O bond.The deviation from this dependence in SS with Ni and Cd is explained by their individual features,which result in changes in the degree of bond covalence in both cationic sublattices.The conducted crystal-chemical analysis made it possible to choose promising SS when creating ferroelectric materials,including textured piezoelectric ceramic materials for piezoelectric transducers for various purposes:Piezotransformers,piezoelectric motors,ultrasonic emitters,filter devices,ultrasonic flaw detectors,accelerometers,etc.
基金Spanish MINECO through the MAT2014-58816-R and MAT2011-2370projects.C.M.F-P.also acknowledges the financial aid of the Spanish FPI Program(BES 2012-053017).
文摘Recently,large phase-change magnetoelectric response has been anticipated by a first-principles investigation of phases in the BiFeO_(3)–BiCoO_(3)perovskite binary system,associated with the existence of a discontinuous morphotropic phase boundary(MPB)between multiferroic polymorphs of rhombohedral and tetragonal symmetries.This might be a general property of multiferroic phase instabilities,and a novel promising approach for room temperature magnetoelectricity.We review here our current inves-tigations on the identification and study of additional material systems,alternative to BiFeO_(3)–BiCoO_(3)that has only been obtained by high pressure synthesis.Three systems,whose phase diagrams were,in principle,liable to show multiferroic MPBs have been addressed:the BiMnO_(3)–PbTiO_(3)and BiFeO_(3)–PbTiO_(3)binary systems,and the BiFeO_(3)–BiMnO_(3)–PbTiO_(3)ternary one.A compre-hensive study of multiferroism across different solid solutions was carried out based on electrical and magnetic characterizations,complemented with mechanical and electromechanical measurements.An in-depth structural analysis was also accomplished when necessary.
文摘Some of the known binary ABO_(3)perovskites with ferro-(FE)or antiferroelectric(AFE)at T_(C)and different magnetic phase tran-sitions(PT):ferro-and antiferromagnetic at T_(N)and also some of their solid solutions are considered.Some correlations between their FE or AFE and/or magnetic PTs temperatures,on the one hand,and their interatomic bond A-O strains,on the other hand,have been constructed.It is shown that in the plotted diagrams these temperatures change with a change inδAO values as follows:classical FEs are followed by multiferroics,starting with BiFeO_(3)and ending with YVO_(3),followed by classical AFEs.At the same time,the temperatures T_(C)and T_(N)experience maxima at the corresponding points for BiFeO_(3),then quickly decrease,and the difference between them,T_(C)-T_(N),basically also decreases,slightly increasing along the way to the point EuTiO_(3).which made it possible to systematize these T_(C)and T_(N).