CuInSe_(2) is an N-type diamond-like semiconductors thermoelectric candidate for power generation at medium temperature with its environmentally friendly and cost-effective properties.However,the intrinsic high therma...CuInSe_(2) is an N-type diamond-like semiconductors thermoelectric candidate for power generation at medium temperature with its environmentally friendly and cost-effective properties.However,the intrinsic high thermal conductivity of CuInSe_(2) limits the enhancement of its thermoelectric performance.Herein,we investigate the thermoelectric performance of N-type CuInSe_(2) materials by incorporating ZnSe through a solid solution strategy.A series of(CuInSe_(2))_(1-x)(ZnSe)_(x)(x=0.0,0.2,0.4,0.6,0.8,1.0)samples were synthesized,forming continuous solid solutions,while introducing minor porosity.ZnSe solid solution effectively reduces the lattice thermal conductivity of the CuInSe_(2) matrix at near-room temperatures,but has a weaker effect at higher temperatures.Due to the intrinsic low carrier concentration of the system,resulting in high resistivity,the maximum figure of merit(ZT)of(CuInSe_(2))0.8(ZnSe)0.2 reaches 0.08 at 773 K.Despite the relatively low ZT,the solid solution strategy proves effective in reducing the lattice thermal conductivity near-room temperature and offers potential for cost-effective thermoelectric materials.展开更多
Li_(6)ZnO_(4)was chemically modified by nickel addition,in order to develop different compositions of the solid solution Li_(6)Zn_(1-x)Ni_(x)O_(4).These materials were evaluated bifunctionally;analyzing their CO_(2)ca...Li_(6)ZnO_(4)was chemically modified by nickel addition,in order to develop different compositions of the solid solution Li_(6)Zn_(1-x)Ni_(x)O_(4).These materials were evaluated bifunctionally;analyzing their CO_(2)capture performances,aswell as on their catalytic properties for H_(2)production via dry reforming of methane(DRM).The crystal structures of Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples were determined through X-ray diffraction,which confirmed the integration of nickel ions up to a concentration around 20 mol%,meanwhile beyond this value,a secondary phase was detected.These results were supported by XPS and TEM analyses.Then,dynamic and isothermal thermogravimetric analyses of CO_(2)capture revealed that Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples exhibited good CO_(2)chemisorption efficiencies,similarly to the pristine Li_(6)ZnO_(4)chemisorption trends observed.Moreover,a kinetic analysis of CO_(2)isothermal chemisorptions,using the Avrami-Erofeev model,evidenced an increment of the constant rates as a function of the Ni content.Since Ni^(2+)ions incorporation did not reduce the CO_(2)capture efficiency and kinetics,the catalytic properties of thesematerialswere evaluated in the DRM process.Results demonstrated that nickel ions favored hydrogen(H_(2))production over the pristine Li_(6)ZnO_(4)phase,despite a second H2 production reaction was determined,methane decomposition.Thereby,Li_(6)Zn_(1-x)Ni_(x)O_(4)ceramics can be employed as bifunctional materials.展开更多
Most studies have shown that oxygen vacancies on Ce_(x)Zr_(1-x)O_(2) solid solution are important for enhancing the catalytic oxidation performance.However,a handful of studies investigated the different roles of surf...Most studies have shown that oxygen vacancies on Ce_(x)Zr_(1-x)O_(2) solid solution are important for enhancing the catalytic oxidation performance.However,a handful of studies investigated the different roles of surface and subsurface oxygen vacancies on the performance and mechanisms of catalysts.Herein,a series of zirconium doping on CeO_(2) samples(CeO_(2),Ce_(0.95)Zr_(0.05)O_(2),and Ce_(0.8)5Zr_(0.15)O_(2))with various surface-to-subsurface oxygen vacancies ratios have been synthesized and applied in toluene catalytic oxidation.The obtained Ce_(0.95)Zr_(0.05)O_(2) exhibits an excellent catalytic performance with a 90%toluene conversion at 295℃,which is 68℃lower than that of CeO_(2).Additionally,the obtained Ce_(0.95)Zr_(0.05)O_(2)catalyst also exhibited good catalytic stability and water resistance.The XRD and HRTEM results show that Zr ions are incorporated into CeO_(2) lattice,forming Ce_(x)Zr_(1-x)O_(2) solid solution.Temperature-programmed experiments reveal that Ce_(0.95)Zr_(0.05)O_(2) shows excellent lowtemperature reducibility and abundant surface oxygen species.In-situ DRIFTS tests were used to probe the reaction mechanism,and the function of Zr doping in promoting the activation of oxygen was further determined.Density functional theory(DFT)calculations indicate that the vacancy formation energy and O_(2) adsorption energy are both lower on Ce_(0.95)Zr_(0.05)O_(2),confirming the reason for its superior catalytic performance.展开更多
To separate the phosphorus-containing phase from steel slag,the effects of B_(2)O_(3)and Na_(2)B_(4)O_(7)on the enrichment of phosphorus-containing phases in Ca_(2)SiO_(4)–Ca_(3)(PO_(4))_(2)(C_(2)S–C_(3)P)solid solu...To separate the phosphorus-containing phase from steel slag,the effects of B_(2)O_(3)and Na_(2)B_(4)O_(7)on the enrichment of phosphorus-containing phases in Ca_(2)SiO_(4)–Ca_(3)(PO_(4))_(2)(C_(2)S–C_(3)P)solid solution were comparatively analyzed through theoretical calculations and experimental investigations.The results indicate that the optimum reaction temperature between B_(2)O_(3)and C_(2)S–C_(3)P is 800℃.The phase compositions of C_(2)S–C_(3)P equilibrium system with 5 wt.%B_(2)O_(3)at 800℃ included Ca_(3)(PO_(4))_(2),CaSiO_(3)and Ca11B_(2)Si_(4)O_(22),among which the content of Ca_(3)(PO_(4))_(2)was the highest.For C_(2)S–C_(3)P with 5 wt.%Na_(2)B_(4)O_(7)equilibrium system,Ca_(3)(PO_(4))_(2),CaSiO_(3),Ca11B_(2)Si_(4)O_(22)and Na_(2)Ca_(2)P_(2)O_(8)were independent at 390–690℃.Ca_(3)(PO_(4))_(2)and Ca_(2)SiO_(4)precipitated in the solid solution when the addition of B_(2)O_(3)was more than 6 wt.%,and the content of Ca_(3)(PO_(4))_(2)raised with the increase in the addition of B_(2)O_(3).The main phases in the C_(2)S–C_(3)P solid solution with Na_(2)B_(4)O_(7)were(Ca_(2)SiO_(4))0.05[Ca_(3)(PO_(4))_(2)],Ca_(2)SiO_(4)and Na_(3)Ca_(6)(PO_(4))_(5)at 650℃.And when the addition of Na_(2)B_(4)O_(7)exceeded 6 wt.%,the content of Na_(3)Ca_(6)(PO_(4))_(5)increased significantly.There was no precipitation of Ca_(3)(PO_(4))_(2)or boron-containing phase in the samples with Na_(2)B_(4)O_(7),but a small proportion of Ca_(3)(PO_(4))_(2)transformed into(Ca_(2)SiO_(4))0.05[Ca_(3)(PO_(4))_(2)],and Ca^(2+)was partially replaced by Na^(+)to generate Na_(3)Ca_(6)(PO_(4))_(5).As a result,the temperature for Na_(2)B_(4)O_(7)to enrich the phosphorus-containing phase in C_(2)S–C_(3)P solid solution was lower than that for B_(2)O_(3).However,the grade of the phosphorus-containing phase for Na_(2)B_(4)O_(7)was lower than that for B_(2)O_(3).展开更多
The low-dose X-ray induced long afterglow near infrared(NIR)luminescence from Cr^(3+)doped Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions was investigated.The structure analysis shows the good formation of Zn_(1-x)Cd...The low-dose X-ray induced long afterglow near infrared(NIR)luminescence from Cr^(3+)doped Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions was investigated.The structure analysis shows the good formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions,which possesses a cubic spinel structure with Fd3m space group.The formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions induces the obvious increase of long afterglow near infrared luminescence excited by low-dose X-ray,When the content of doped Cd^(2+)reaches 0.1,the low-dose X-ray induced long afterglow NIR luminescence is the maximum.More importantly,only 5 s Xray irradiation can induce more than 6 h NIR afterglow emission,of which the afterglow luminescent intensity is still 5 times stronger than the background intensity after 6 h.The thermoluminescent results show that under the 5 s exposure of X-ray,the trap density of Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):Cr^(3+)is much higher than that of ZnGa_(2)O_(4):Cr^(3+).The replacement of Cd^(2+)ions with large radius at Zn^(2+)sites causes the increase of de fects and dislocations,which results in the obvious increase of trap co ncentrations.And the addition of high-z number elements Cd^(2+)would enhance the X-ray absorption of the solid solutions,which thus can be easily excited by low-dose X-ray.Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):1%Cr^(3+)solid solution is a potential candidate of lowdose X-ray induced long afterglow luminescent materials.展开更多
Ce0.6Zr0.4O2 solid solution ultrafine particle was prepared in the cyclohexane/water/OP-10/n-hexanol reversed microemulsion. The quasi-ternary phase diagram investigations showed that the system has narrow W/O type mi...Ce0.6Zr0.4O2 solid solution ultrafine particle was prepared in the cyclohexane/water/OP-10/n-hexanol reversed microemulsion. The quasi-ternary phase diagram investigations showed that the system has narrow W/O type microemulison region, so it is the proper system to prepare Ce0.6Zr0.4O2 solid solution ultrafine particle. Some physical-chemical techniques such as TG/DTA, XRD, BET, and HRTEM are used to characterize the resultant powders. The results show that the fluorite cubic Ce0.6Zr0.4O2 solid solution is obtained at 400 ℃. The surface area is （146.7 m^2·g^-1）, which is higher than the surface area for sol-gel prepared sample （59.5m^2·g^-1）. HRTEM images indicated that the Ce0.6Zr0.4O2 solid solution ultrafine particle is well-crystallized, narrow size distribution, less agglomeration, within mean size of 5 -7 nm.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
The CeO_2-ZrO_2 solid solutions were prepared by a reverse microemulsion method. The effect of preparation parameters on the surface area and crystalline form of the solid solutions were studied by the BET surface are...The CeO_2-ZrO_2 solid solutions were prepared by a reverse microemulsion method. The effect of preparation parameters on the surface area and crystalline form of the solid solutions were studied by the BET surface area and XRD analysis. The studies indicate that the separation of the microemulsion phase during the preparation procedure can decrease the specific surface area of sample, adding hydrogen peroxide in the matrix solution can increase the specific surface area and stability of sample. The surface area of sample calcined at 550 ℃ for 5 h is 149 m^2·g^(-1), and that calcined at 900 ℃ for 6 h is 88 m^2·g^(-1). The sample with tetragonal symmetry Ce_(0.5)Zr_(0.5)O_2 phase has a higher stability.展开更多
CO_(2)reduction by CH4(CRM)to produce fuel is of great significance for solar energy storage and eliminating greenhouse gas.Herein,the catalyst of ultrafine Ni nanoparticles supported on CeZrNiO_(2)solid solution(Ni@C...CO_(2)reduction by CH4(CRM)to produce fuel is of great significance for solar energy storage and eliminating greenhouse gas.Herein,the catalyst of ultrafine Ni nanoparticles supported on CeZrNiO_(2)solid solution(Ni@CZNO)was synthesized by the sol-gel method.High yield of H_(2)and CO(58.0 and 69.8 mmol min^(-1)g^(-1))and excellent durability(50 h)were achieved by photothermal catalytic CRM merely under focused light irradiation.Structural characterization and DFT calculations reveal that CZNO has rich oxygen vacancies that can adsorb and activate CO_(2)to produce reactive oxygen species.Oxygen species are transferred to ultrafine Ni nanoparticles through the rich Ni-CZNO interface to accelerate carbon oxidation,thereby maintaining the excellent catalytic stability of the catalyst.Moreover,the experimental results reveal that light irradiation can not only enhance the photothermal catalytic CRM activity through photothermal conversion and molecular activation,but also improve the stability by increasing the concentration of oxygen vacancies and inhibiting CO disproportionation.展开更多
Fe^3+and Zn^2+ions were doped into the lattice of CeO2 via the hydrothermal method.The micro structure and spectra features were analyzed systemically.XRD results show that the solid solubility of Fe^3+and Zn^2+ions i...Fe^3+and Zn^2+ions were doped into the lattice of CeO2 via the hydrothermal method.The micro structure and spectra features were analyzed systemically.XRD results show that the solid solubility of Fe^3+and Zn^2+ions in Ce1-x(Fe0.5Zn0.5)xO2 can be identified as x=0.16.The cell volumes are decreased by increasing the doped content.The TEM graphs prove that the grain size of the sample is about 10 nm,and the EDS result indicates that the doped contents are in accordance with that of the theory concentrations.Meanwhile,the doping also causes the increasing concentrations of the defects and oxygen vacancies which are supported by the XPS,Raman,UV and PL characterizations.The samples exhibit better catalytic activities for improving the hydrogen storage properties and the electrochemical kinetics of the ball milled Mg2Ni based composites.Further,the catalysis effects are improved by increasing the doped contents,which can be ascribed to the increasing contents of the oxygen vacancies,defects,the special electron transition states and the nature of the doped ions in CeO2-based solid solutions.展开更多
A series of SnO2‐based catalysts modified by Mn, Zr, Ti and Pb oxides with a Sn/M （M=Mn, Zr, Ti and Pb） molar ratio of 9/1 were prepared by a co‐precipitation method and used for CH4 and CO oxidation. The Mn3＋, ...A series of SnO2‐based catalysts modified by Mn, Zr, Ti and Pb oxides with a Sn/M （M=Mn, Zr, Ti and Pb） molar ratio of 9/1 were prepared by a co‐precipitation method and used for CH4 and CO oxidation. The Mn3＋, Zr4＋, Ti4＋and Pb4＋cations are incorporated into the lattice of tetragonal rutile SnO2 to form a solid solution structure. As a consequence, the surface area and thermal stability of the catalysts are improved. Moreover, the oxygen species of the modified catalysts become easier to be reduced. Therefore, the oxidation activity over the catalysts was improved, except for the one modified by Pb oxide. Manganese oxide demonstrates the best promotional effects for SnO2. Using an X‐ray diffraction extrapolation method, the lattice capacity of SnO2 for Mn2O3 was 0.135 g Mn2O3/g SnO2, which indicates that to form stable solid solution, only 21%Sn4＋cations in the lattice can be maximally replaced by Mn3＋. If the amount of Mn3＋cations is over the capacity, Mn2O3 will be formed, which is not favorable for the activity of the catalysts. The Sn rich samples with only Sn‐Mn solid solution phase show higher activity than the ones with excess Mn2O3 species.展开更多
Nanostructured CeO_2-ZrO_2 materials are an irreplaceable constituent in catalytic systems for automobile exhaust purification due to their unique oxygen storage capacity(OSC). However, traditional CeO_2-ZrO_2 materia...Nanostructured CeO_2-ZrO_2 materials are an irreplaceable constituent in catalytic systems for automobile exhaust purification due to their unique oxygen storage capacity(OSC). However, traditional CeO_2-ZrO_2 materials are easy to sinter at high temperature, which causes a sharp decrease of OSC. In this paper,La^(3+) , Nd^(3+) and Y^(3+) are chosen as dopants for CeO_2-ZrO_2 to improve anti-sintering and OSC properties.The Ce_(0.17) Zr_(0.73) La_(0.02) Nd_(0.04) Y_(0.04) O_2 powders(CZLNY) were prepared by co-precipitation method. The effects of grain sizes with different mixed chlorinated solution concentrations on performances were investigated. X-ray diffraction(XRD) and transmission electron micrograph(TEM) were performed to calculate the grain sizes of CZLNY. The specific surfaces, OSC and redox properties were investigated by N_2 adsorption/desorption and temperature programmed reduction(H2-TPR). The results show that introducing La^(3+) , Nd^(3+) and Y^(3+) into CeO_2-ZrO_2 lattice can improve the stability of phase structure and anti-sintering ability. Moreover, low concentration of mixed chlorinated solution remarkably improves structural and textural properties of CZLNY. Relatively large fresh grain exhibits superior thermal stability and OSC under the condition of being calcined at 800℃ for 3 h. The specific surface and OSC are42.37 m^2/g and 333.13 mmol/g after calcining at 1000℃ for 10 h, respectively. This is owing to the low sintered driving force of large grain and long-range migration energy of large pores during the sintering process, which are beneficial to the stability of structure in CZLNY materials.展开更多
Nanosized Fe^3＋ and Eu^3＋ codoped CeO2 solid solutions were synthesized via hydrothermal method. The crystalline structure of Ce1-x（Fe0.5Eu0.5）xO2-δx=0.00–0.30） solid solutions was carried out by the X-ray diff...Nanosized Fe^3＋ and Eu^3＋ codoped CeO2 solid solutions were synthesized via hydrothermal method. The crystalline structure of Ce1-x（Fe0.5Eu0.5）xO2-δx=0.00–0.30） solid solutions was carried out by the X-ray diffraction technique, and the spectrum features were identified by UV-Vis and Raman spectroscopy, respectively. It was observed that the cell parameters were first increased then decreased by increasing the doped ions content. The phase separation was detected when the dopant concentration reached to x=0.30. UV-Vis spectrum showed that the width of the band gap gradually reduced by increasing the doped content, and the solid solubility was determined to be x=0.20. The Raman technique displayed that the peak position of F2g mode gradually shifted to lower frequencies from 465 cm^–1 for x=0.00 to 440 cm^–1 for x=0.20. The catalytic effects of Ce1-x（Fe0.5Eu0.5）xO2-δsolid solutions on the electrochemistry properties of Mg2Ni/Ni were measured by mixing them together via ball milling technique. The electrochemical properties of the Mg_2Ni/Ni-Ce1-x（Fe0.5Eu0.5）xO2-δcomposites showed that the maximum discharge capability Cmax and the cycle stability were improved obviously. Meanwhile, the EIS characteristic also indicated that the doped solid solutions could enhance the rate of charge transfer on the surface of alloy. The catalytic effect of the solid solutions was speculated to rely on both the concentration of oxygen vacancies and the cell volumes of the solid solutions.展开更多
In order to reduce the oxidizing and volatilizing caused by Mg element in the traditional methods for synthesizing Mg2Sil-xSnx （x=0.2, 0.4, 0.6, 0.8） solid solutions, microwave irradiation techniques were used in pr...In order to reduce the oxidizing and volatilizing caused by Mg element in the traditional methods for synthesizing Mg2Sil-xSnx （x=0.2, 0.4, 0.6, 0.8） solid solutions, microwave irradiation techniques were used in preparing them as thermoelectric materials. Structure and phase composition of the obtained materials were investigated by X-ray diffraction （XRD）. The electrical conductivity, Seebeck coefficient and thermal conductivity were measured as a function of temperature from 300 to 750 K. It is found that Mg2Si1-xSnx solid solutions are well formed with excessive content of 5% （molar fraction） Mg from the stoichiometric MgESil.xSnx under microwave irradiation. A maximum dimensionless figure of merit, ZT, of about 0.26 is obtained for Mg2Si1-xSnx solid solutions at about 500 K for x=0.6.展开更多
CexZr1-xO2 complex oxides doped by transition metal(Fe, Mn, Cu) were prepared by precipitation method. Thermal stability of samples was characterized by XRD, surface areas were measured by BET method and reductive pro...CexZr1-xO2 complex oxides doped by transition metal(Fe, Mn, Cu) were prepared by precipitation method. Thermal stability of samples was characterized by XRD, surface areas were measured by BET method and reductive property was characterized by TPR. The results show that MnO2 can be dispersed in solid solution after calcined at 1273 K, when the loading is 12%, while Fe and Cu is easy to separate from samples at this temperature. Samples doped simultaneously by Fe, Mn or Fe, Cu demonstrated high reactive property at low temperature. The starting reduction temperature are 413 and 373 K, respectively. TPR results also show a broad range of reductive temperature exists in these bi-metal doped samples.展开更多
It is confirmed that the solid solution temperature range to obtain optimal magnetic properties is different for the magnets with different Fe contents,and the correlation between magnetic properties and microstructur...It is confirmed that the solid solution temperature range to obtain optimal magnetic properties is different for the magnets with different Fe contents,and the correlation between magnetic properties and microstructures influenced by solid solution temperature(Ts)has been systematically studied.The optimal solid solution temperature range is 1413-1463 K for the Sm(Co_(bal)Fe_(0.213)Cu_(0.073)Zr_(0.024))_(7.6)magnet,which is higher than that of the Sm(Co_(bal)Fe_(0.262)Cu_(0.073)Zr_(0.024))_(7.6)magnet(1403-1453 K),and the optimal T_s range is about 50 K for both of the magnets.The solid solution temperature range shifting toward relatively high temperature is due to the increase in a phase transition temperature.The magnet solution-treated at proper temperature exhibits 1:7 H single phase,and intact cell structure and high Cu concentration(23.12 at%)in the cell boundary are found after aging process,which makes the magnet shows high intrinsic coercivity(H_(cj))and magnetic field at knee-point(H_(knee)).At a lower solid solution temperature,the 2:17 H,1:5 H and Zr-rich precipitation phases appear,which affects the cell structure,density of lamellar phase and Cu concentration in the cell boundary,leading to the reduced magnetic properties.However,at a higher solid solution temperature,there exist obviously light gray and dark regions with different Sm,Cu and Fe contents in scanning electron microscopy observation,and the magnet shows low pinning field in the two regions and incomplete cell structure,resulting in an inferior H_(cj)and H_(knee).展开更多
The three way catalysts (TWCs) promoters (Ce Zr)O 2, (Pr Ce Zr)O 2 and (Pr Zr)O 2 were prepared by sol gel like method. They were characterized by XRD, EXAFS and BET surface area determination. The reduction ...The three way catalysts (TWCs) promoters (Ce Zr)O 2, (Pr Ce Zr)O 2 and (Pr Zr)O 2 were prepared by sol gel like method. They were characterized by XRD, EXAFS and BET surface area determination. The reduction features of the promoters were measured by temperature programmed reduction (TPR) of H 2 to access the potential for the promoters containing praseodymia as oxygen storage component in three way catalyst. The (Pr Zr)O 2 cubic solid solution is formed at high temperature up to 800 ℃, which makes it more reducible than the (Ce Zr)O 2 solid solution. For the (Pr Ce Zr)O 2 samples, the ternary solid solution plays an important role in the reduction process. The performance of the three way catalysts with fully formulated Pt, Pd and Rh is proceeded by using both light off temperature under a stoichiometric gas composition and the conversion of CO, C 3H 6 and NO under changing air/fuel ratio at a constant reaction temperature 400 ℃ . The results indicate that a small amount of praseodymia doping into (Ce Zr)O 2 favors the light off temperature of C 3H 6 and NO, and all the catalysts containing praseodymia obviously exhibits enhanced width of S value for NO conversion at lean region ( S ≥1.00).展开更多
基金supported by the Fundamental Research Funds for the Central Universities under Grant No.2024BRB010。
文摘CuInSe_(2) is an N-type diamond-like semiconductors thermoelectric candidate for power generation at medium temperature with its environmentally friendly and cost-effective properties.However,the intrinsic high thermal conductivity of CuInSe_(2) limits the enhancement of its thermoelectric performance.Herein,we investigate the thermoelectric performance of N-type CuInSe_(2) materials by incorporating ZnSe through a solid solution strategy.A series of(CuInSe_(2))_(1-x)(ZnSe)_(x)(x=0.0,0.2,0.4,0.6,0.8,1.0)samples were synthesized,forming continuous solid solutions,while introducing minor porosity.ZnSe solid solution effectively reduces the lattice thermal conductivity of the CuInSe_(2) matrix at near-room temperatures,but has a weaker effect at higher temperatures.Due to the intrinsic low carrier concentration of the system,resulting in high resistivity,the maximum figure of merit(ZT)of(CuInSe_(2))0.8(ZnSe)0.2 reaches 0.08 at 773 K.Despite the relatively low ZT,the solid solution strategy proves effective in reducing the lattice thermal conductivity near-room temperature and offers potential for cost-effective thermoelectric materials.
基金This work was carried out in the framework of PAPIIT-UNAM(IN-205823)project.
文摘Li_(6)ZnO_(4)was chemically modified by nickel addition,in order to develop different compositions of the solid solution Li_(6)Zn_(1-x)Ni_(x)O_(4).These materials were evaluated bifunctionally;analyzing their CO_(2)capture performances,aswell as on their catalytic properties for H_(2)production via dry reforming of methane(DRM).The crystal structures of Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples were determined through X-ray diffraction,which confirmed the integration of nickel ions up to a concentration around 20 mol%,meanwhile beyond this value,a secondary phase was detected.These results were supported by XPS and TEM analyses.Then,dynamic and isothermal thermogravimetric analyses of CO_(2)capture revealed that Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples exhibited good CO_(2)chemisorption efficiencies,similarly to the pristine Li_(6)ZnO_(4)chemisorption trends observed.Moreover,a kinetic analysis of CO_(2)isothermal chemisorptions,using the Avrami-Erofeev model,evidenced an increment of the constant rates as a function of the Ni content.Since Ni^(2+)ions incorporation did not reduce the CO_(2)capture efficiency and kinetics,the catalytic properties of thesematerialswere evaluated in the DRM process.Results demonstrated that nickel ions favored hydrogen(H_(2))production over the pristine Li_(6)ZnO_(4)phase,despite a second H2 production reaction was determined,methane decomposition.Thereby,Li_(6)Zn_(1-x)Ni_(x)O_(4)ceramics can be employed as bifunctional materials.
基金supported by the National Natural Science Foundation(No.51678291)the Basic Science(Natural Science)Research in Higher Education in Jiangsu Province(No.23KJA610003)the High-level Scientific Research Foundation for the introduction of talent in Nanjing Institute of Technology(No.YKJ201999)。
文摘Most studies have shown that oxygen vacancies on Ce_(x)Zr_(1-x)O_(2) solid solution are important for enhancing the catalytic oxidation performance.However,a handful of studies investigated the different roles of surface and subsurface oxygen vacancies on the performance and mechanisms of catalysts.Herein,a series of zirconium doping on CeO_(2) samples(CeO_(2),Ce_(0.95)Zr_(0.05)O_(2),and Ce_(0.8)5Zr_(0.15)O_(2))with various surface-to-subsurface oxygen vacancies ratios have been synthesized and applied in toluene catalytic oxidation.The obtained Ce_(0.95)Zr_(0.05)O_(2) exhibits an excellent catalytic performance with a 90%toluene conversion at 295℃,which is 68℃lower than that of CeO_(2).Additionally,the obtained Ce_(0.95)Zr_(0.05)O_(2)catalyst also exhibited good catalytic stability and water resistance.The XRD and HRTEM results show that Zr ions are incorporated into CeO_(2) lattice,forming Ce_(x)Zr_(1-x)O_(2) solid solution.Temperature-programmed experiments reveal that Ce_(0.95)Zr_(0.05)O_(2) shows excellent lowtemperature reducibility and abundant surface oxygen species.In-situ DRIFTS tests were used to probe the reaction mechanism,and the function of Zr doping in promoting the activation of oxygen was further determined.Density functional theory(DFT)calculations indicate that the vacancy formation energy and O_(2) adsorption energy are both lower on Ce_(0.95)Zr_(0.05)O_(2),confirming the reason for its superior catalytic performance.
基金funding support from the National Key R&D Program of China(2020YFC1909105)the 2023 Basic Research Foundation Project for Universities in the Inner Mongolia Autonomous Region(2023RCTD006)+1 种基金the Major Science and Technology Project of Inner Mongolia Autonomous Region(2021ZD0016)the National Natural Science Foundation of China(51664044).
文摘To separate the phosphorus-containing phase from steel slag,the effects of B_(2)O_(3)and Na_(2)B_(4)O_(7)on the enrichment of phosphorus-containing phases in Ca_(2)SiO_(4)–Ca_(3)(PO_(4))_(2)(C_(2)S–C_(3)P)solid solution were comparatively analyzed through theoretical calculations and experimental investigations.The results indicate that the optimum reaction temperature between B_(2)O_(3)and C_(2)S–C_(3)P is 800℃.The phase compositions of C_(2)S–C_(3)P equilibrium system with 5 wt.%B_(2)O_(3)at 800℃ included Ca_(3)(PO_(4))_(2),CaSiO_(3)and Ca11B_(2)Si_(4)O_(22),among which the content of Ca_(3)(PO_(4))_(2)was the highest.For C_(2)S–C_(3)P with 5 wt.%Na_(2)B_(4)O_(7)equilibrium system,Ca_(3)(PO_(4))_(2),CaSiO_(3),Ca11B_(2)Si_(4)O_(22)and Na_(2)Ca_(2)P_(2)O_(8)were independent at 390–690℃.Ca_(3)(PO_(4))_(2)and Ca_(2)SiO_(4)precipitated in the solid solution when the addition of B_(2)O_(3)was more than 6 wt.%,and the content of Ca_(3)(PO_(4))_(2)raised with the increase in the addition of B_(2)O_(3).The main phases in the C_(2)S–C_(3)P solid solution with Na_(2)B_(4)O_(7)were(Ca_(2)SiO_(4))0.05[Ca_(3)(PO_(4))_(2)],Ca_(2)SiO_(4)and Na_(3)Ca_(6)(PO_(4))_(5)at 650℃.And when the addition of Na_(2)B_(4)O_(7)exceeded 6 wt.%,the content of Na_(3)Ca_(6)(PO_(4))_(5)increased significantly.There was no precipitation of Ca_(3)(PO_(4))_(2)or boron-containing phase in the samples with Na_(2)B_(4)O_(7),but a small proportion of Ca_(3)(PO_(4))_(2)transformed into(Ca_(2)SiO_(4))0.05[Ca_(3)(PO_(4))_(2)],and Ca^(2+)was partially replaced by Na^(+)to generate Na_(3)Ca_(6)(PO_(4))_(5).As a result,the temperature for Na_(2)B_(4)O_(7)to enrich the phosphorus-containing phase in C_(2)S–C_(3)P solid solution was lower than that for B_(2)O_(3).However,the grade of the phosphorus-containing phase for Na_(2)B_(4)O_(7)was lower than that for B_(2)O_(3).
基金Project supported by the State Key Research Project of Shandong Natural Science Foundation(ZR2020KB019)the fund of"Two-Hundred Talent"Plan of Yantai City+1 种基金the National Natural Science Foundation of China(11974013)the Natural Science Foundation of Fujian Province(2022J011270)。
文摘The low-dose X-ray induced long afterglow near infrared(NIR)luminescence from Cr^(3+)doped Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions was investigated.The structure analysis shows the good formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions,which possesses a cubic spinel structure with Fd3m space group.The formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions induces the obvious increase of long afterglow near infrared luminescence excited by low-dose X-ray,When the content of doped Cd^(2+)reaches 0.1,the low-dose X-ray induced long afterglow NIR luminescence is the maximum.More importantly,only 5 s Xray irradiation can induce more than 6 h NIR afterglow emission,of which the afterglow luminescent intensity is still 5 times stronger than the background intensity after 6 h.The thermoluminescent results show that under the 5 s exposure of X-ray,the trap density of Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):Cr^(3+)is much higher than that of ZnGa_(2)O_(4):Cr^(3+).The replacement of Cd^(2+)ions with large radius at Zn^(2+)sites causes the increase of de fects and dislocations,which results in the obvious increase of trap co ncentrations.And the addition of high-z number elements Cd^(2+)would enhance the X-ray absorption of the solid solutions,which thus can be easily excited by low-dose X-ray.Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):1%Cr^(3+)solid solution is a potential candidate of lowdose X-ray induced long afterglow luminescent materials.
文摘Ce0.6Zr0.4O2 solid solution ultrafine particle was prepared in the cyclohexane/water/OP-10/n-hexanol reversed microemulsion. The quasi-ternary phase diagram investigations showed that the system has narrow W/O type microemulison region, so it is the proper system to prepare Ce0.6Zr0.4O2 solid solution ultrafine particle. Some physical-chemical techniques such as TG/DTA, XRD, BET, and HRTEM are used to characterize the resultant powders. The results show that the fluorite cubic Ce0.6Zr0.4O2 solid solution is obtained at 400 ℃. The surface area is （146.7 m^2·g^-1）, which is higher than the surface area for sol-gel prepared sample （59.5m^2·g^-1）. HRTEM images indicated that the Ce0.6Zr0.4O2 solid solution ultrafine particle is well-crystallized, narrow size distribution, less agglomeration, within mean size of 5 -7 nm.
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The CeO_2-ZrO_2 solid solutions were prepared by a reverse microemulsion method. The effect of preparation parameters on the surface area and crystalline form of the solid solutions were studied by the BET surface area and XRD analysis. The studies indicate that the separation of the microemulsion phase during the preparation procedure can decrease the specific surface area of sample, adding hydrogen peroxide in the matrix solution can increase the specific surface area and stability of sample. The surface area of sample calcined at 550 ℃ for 5 h is 149 m^2·g^(-1), and that calcined at 900 ℃ for 6 h is 88 m^2·g^(-1). The sample with tetragonal symmetry Ce_(0.5)Zr_(0.5)O_2 phase has a higher stability.
基金supported by the National Natural Science Foundation of China(22202121,22005340)Shandong Provincial Natural Science Foundation(ZR2021QB079).
文摘CO_(2)reduction by CH4(CRM)to produce fuel is of great significance for solar energy storage and eliminating greenhouse gas.Herein,the catalyst of ultrafine Ni nanoparticles supported on CeZrNiO_(2)solid solution(Ni@CZNO)was synthesized by the sol-gel method.High yield of H_(2)and CO(58.0 and 69.8 mmol min^(-1)g^(-1))and excellent durability(50 h)were achieved by photothermal catalytic CRM merely under focused light irradiation.Structural characterization and DFT calculations reveal that CZNO has rich oxygen vacancies that can adsorb and activate CO_(2)to produce reactive oxygen species.Oxygen species are transferred to ultrafine Ni nanoparticles through the rich Ni-CZNO interface to accelerate carbon oxidation,thereby maintaining the excellent catalytic stability of the catalyst.Moreover,the experimental results reveal that light irradiation can not only enhance the photothermal catalytic CRM activity through photothermal conversion and molecular activation,but also improve the stability by increasing the concentration of oxygen vacancies and inhibiting CO disproportionation.
基金supported by the National Natural Science Foundation of China(51962028,51501095)the Natural Science Foundation of Inner Mongolia(2017MS(LH)0516,2018MS05040,2018BS05010,2017MS(LH)0519)the Innovation Fund of Inner Mongolia University of Science and Technology(2018YQL02).
文摘Fe^3+and Zn^2+ions were doped into the lattice of CeO2 via the hydrothermal method.The micro structure and spectra features were analyzed systemically.XRD results show that the solid solubility of Fe^3+and Zn^2+ions in Ce1-x(Fe0.5Zn0.5)xO2 can be identified as x=0.16.The cell volumes are decreased by increasing the doped content.The TEM graphs prove that the grain size of the sample is about 10 nm,and the EDS result indicates that the doped contents are in accordance with that of the theory concentrations.Meanwhile,the doping also causes the increasing concentrations of the defects and oxygen vacancies which are supported by the XPS,Raman,UV and PL characterizations.The samples exhibit better catalytic activities for improving the hydrogen storage properties and the electrochemical kinetics of the ball milled Mg2Ni based composites.Further,the catalysis effects are improved by increasing the doped contents,which can be ascribed to the increasing contents of the oxygen vacancies,defects,the special electron transition states and the nature of the doped ions in CeO2-based solid solutions.
基金supported by the National Natural Science Foundation of China (21263015,21567016 and 21503106)the Education Department Foundation of Jiangxi Province (KJLD14005 and GJJ150016)the Natural Science Foundation of Jiangxi Province (20142BAB213013 and 20151BBE50006),which are greatly acknowledged by the authors~~
文摘A series of SnO2‐based catalysts modified by Mn, Zr, Ti and Pb oxides with a Sn/M （M=Mn, Zr, Ti and Pb） molar ratio of 9/1 were prepared by a co‐precipitation method and used for CH4 and CO oxidation. The Mn3＋, Zr4＋, Ti4＋and Pb4＋cations are incorporated into the lattice of tetragonal rutile SnO2 to form a solid solution structure. As a consequence, the surface area and thermal stability of the catalysts are improved. Moreover, the oxygen species of the modified catalysts become easier to be reduced. Therefore, the oxidation activity over the catalysts was improved, except for the one modified by Pb oxide. Manganese oxide demonstrates the best promotional effects for SnO2. Using an X‐ray diffraction extrapolation method, the lattice capacity of SnO2 for Mn2O3 was 0.135 g Mn2O3/g SnO2, which indicates that to form stable solid solution, only 21%Sn4＋cations in the lattice can be maximally replaced by Mn3＋. If the amount of Mn3＋cations is over the capacity, Mn2O3 will be formed, which is not favorable for the activity of the catalysts. The Sn rich samples with only Sn‐Mn solid solution phase show higher activity than the ones with excess Mn2O3 species.
基金Project supported by the National Key Research and Development Program(2017YFC0211002)
文摘Nanostructured CeO_2-ZrO_2 materials are an irreplaceable constituent in catalytic systems for automobile exhaust purification due to their unique oxygen storage capacity(OSC). However, traditional CeO_2-ZrO_2 materials are easy to sinter at high temperature, which causes a sharp decrease of OSC. In this paper,La^(3+) , Nd^(3+) and Y^(3+) are chosen as dopants for CeO_2-ZrO_2 to improve anti-sintering and OSC properties.The Ce_(0.17) Zr_(0.73) La_(0.02) Nd_(0.04) Y_(0.04) O_2 powders(CZLNY) were prepared by co-precipitation method. The effects of grain sizes with different mixed chlorinated solution concentrations on performances were investigated. X-ray diffraction(XRD) and transmission electron micrograph(TEM) were performed to calculate the grain sizes of CZLNY. The specific surfaces, OSC and redox properties were investigated by N_2 adsorption/desorption and temperature programmed reduction(H2-TPR). The results show that introducing La^(3+) , Nd^(3+) and Y^(3+) into CeO_2-ZrO_2 lattice can improve the stability of phase structure and anti-sintering ability. Moreover, low concentration of mixed chlorinated solution remarkably improves structural and textural properties of CZLNY. Relatively large fresh grain exhibits superior thermal stability and OSC under the condition of being calcined at 800℃ for 3 h. The specific surface and OSC are42.37 m^2/g and 333.13 mmol/g after calcining at 1000℃ for 10 h, respectively. This is owing to the low sintered driving force of large grain and long-range migration energy of large pores during the sintering process, which are beneficial to the stability of structure in CZLNY materials.
基金Project supported by the National Natural Science Foundation of China(51501059)Talent Incubation Funding of School of Materials and Metallurgy and Inner Mongolia University of Science and Technology(2014CY012)
文摘Nanosized Fe^3＋ and Eu^3＋ codoped CeO2 solid solutions were synthesized via hydrothermal method. The crystalline structure of Ce1-x（Fe0.5Eu0.5）xO2-δx=0.00–0.30） solid solutions was carried out by the X-ray diffraction technique, and the spectrum features were identified by UV-Vis and Raman spectroscopy, respectively. It was observed that the cell parameters were first increased then decreased by increasing the doped ions content. The phase separation was detected when the dopant concentration reached to x=0.30. UV-Vis spectrum showed that the width of the band gap gradually reduced by increasing the doped content, and the solid solubility was determined to be x=0.20. The Raman technique displayed that the peak position of F2g mode gradually shifted to lower frequencies from 465 cm^–1 for x=0.00 to 440 cm^–1 for x=0.20. The catalytic effects of Ce1-x（Fe0.5Eu0.5）xO2-δsolid solutions on the electrochemistry properties of Mg2Ni/Ni were measured by mixing them together via ball milling technique. The electrochemical properties of the Mg_2Ni/Ni-Ce1-x（Fe0.5Eu0.5）xO2-δcomposites showed that the maximum discharge capability Cmax and the cycle stability were improved obviously. Meanwhile, the EIS characteristic also indicated that the doped solid solutions could enhance the rate of charge transfer on the surface of alloy. The catalytic effect of the solid solutions was speculated to rely on both the concentration of oxygen vacancies and the cell volumes of the solid solutions.
基金Project(2009BB4228) supported by the Natural Science Foundation of Chongqing City,ChinaProject(CK2010Z09) supported by the Research Foundation of Chongqing University of Science and Technology,China
文摘In order to reduce the oxidizing and volatilizing caused by Mg element in the traditional methods for synthesizing Mg2Sil-xSnx （x=0.2, 0.4, 0.6, 0.8） solid solutions, microwave irradiation techniques were used in preparing them as thermoelectric materials. Structure and phase composition of the obtained materials were investigated by X-ray diffraction （XRD）. The electrical conductivity, Seebeck coefficient and thermal conductivity were measured as a function of temperature from 300 to 750 K. It is found that Mg2Si1-xSnx solid solutions are well formed with excessive content of 5% （molar fraction） Mg from the stoichiometric MgESil.xSnx under microwave irradiation. A maximum dimensionless figure of merit, ZT, of about 0.26 is obtained for Mg2Si1-xSnx solid solutions at about 500 K for x=0.6.
文摘CexZr1-xO2 complex oxides doped by transition metal(Fe, Mn, Cu) were prepared by precipitation method. Thermal stability of samples was characterized by XRD, surface areas were measured by BET method and reductive property was characterized by TPR. The results show that MnO2 can be dispersed in solid solution after calcined at 1273 K, when the loading is 12%, while Fe and Cu is easy to separate from samples at this temperature. Samples doped simultaneously by Fe, Mn or Fe, Cu demonstrated high reactive property at low temperature. The starting reduction temperature are 413 and 373 K, respectively. TPR results also show a broad range of reductive temperature exists in these bi-metal doped samples.
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0700903)the National Natural Science Foundation of China(Nos.51871063 and 51590882)。
文摘It is confirmed that the solid solution temperature range to obtain optimal magnetic properties is different for the magnets with different Fe contents,and the correlation between magnetic properties and microstructures influenced by solid solution temperature(Ts)has been systematically studied.The optimal solid solution temperature range is 1413-1463 K for the Sm(Co_(bal)Fe_(0.213)Cu_(0.073)Zr_(0.024))_(7.6)magnet,which is higher than that of the Sm(Co_(bal)Fe_(0.262)Cu_(0.073)Zr_(0.024))_(7.6)magnet(1403-1453 K),and the optimal T_s range is about 50 K for both of the magnets.The solid solution temperature range shifting toward relatively high temperature is due to the increase in a phase transition temperature.The magnet solution-treated at proper temperature exhibits 1:7 H single phase,and intact cell structure and high Cu concentration(23.12 at%)in the cell boundary are found after aging process,which makes the magnet shows high intrinsic coercivity(H_(cj))and magnetic field at knee-point(H_(knee)).At a lower solid solution temperature,the 2:17 H,1:5 H and Zr-rich precipitation phases appear,which affects the cell structure,density of lamellar phase and Cu concentration in the cell boundary,leading to the reduced magnetic properties.However,at a higher solid solution temperature,there exist obviously light gray and dark regions with different Sm,Cu and Fe contents in scanning electron microscopy observation,and the magnet shows low pinning field in the two regions and incomplete cell structure,resulting in an inferior H_(cj)and H_(knee).
文摘The three way catalysts (TWCs) promoters (Ce Zr)O 2, (Pr Ce Zr)O 2 and (Pr Zr)O 2 were prepared by sol gel like method. They were characterized by XRD, EXAFS and BET surface area determination. The reduction features of the promoters were measured by temperature programmed reduction (TPR) of H 2 to access the potential for the promoters containing praseodymia as oxygen storage component in three way catalyst. The (Pr Zr)O 2 cubic solid solution is formed at high temperature up to 800 ℃, which makes it more reducible than the (Ce Zr)O 2 solid solution. For the (Pr Ce Zr)O 2 samples, the ternary solid solution plays an important role in the reduction process. The performance of the three way catalysts with fully formulated Pt, Pd and Rh is proceeded by using both light off temperature under a stoichiometric gas composition and the conversion of CO, C 3H 6 and NO under changing air/fuel ratio at a constant reaction temperature 400 ℃ . The results indicate that a small amount of praseodymia doping into (Ce Zr)O 2 favors the light off temperature of C 3H 6 and NO, and all the catalysts containing praseodymia obviously exhibits enhanced width of S value for NO conversion at lean region ( S ≥1.00).
