Different amounts of dysprosium oxide were incorporated into barium titanate powders synthesized by hydrothermal method. Relations of substitution behaviors and lattice parameters with solid-solubility were studied. F...Different amounts of dysprosium oxide were incorporated into barium titanate powders synthesized by hydrothermal method. Relations of substitution behaviors and lattice parameters with solid-solubility were studied. Furthermore, the influences of dysprosium oxide doping fraction on grain size and dielectric properties of barium titanate ceramic, including dielectric constant and breakdown electric field strength , were investigated via scanning electron microscope, X-ray diffraction and electric property tester. The results show that dysprosium oxide can restrain abnormal grain growth during sintering and that fine-grained and high density of barium titanate ceramic can result in excellent dielectric properties. As mass fraction of dysprosium oxide is 0.6%, the lattice parameters of grain increase to the maximum because of the lowest vacancy concentration. The electric property parameters are cited as following： dielectric constant （25 ℃ ） reaches 4100, the change in relative dielectric constant with temperature is - 10% to 10% within the range of - 15 - 100 ℃, breakdown electric field strength （alternating current） achieves 3.2 kV·mm^-1, which can be used in manufacturing high voltage ceramic capacitors展开更多
An investigation into the corrosion behavior of pure Mo50Re and rare earth oxide-doped Mo50Re,produced by spark plasma sintering,was performed in Ringer's physiologic solution at a temperature of 37°C.Potenti...An investigation into the corrosion behavior of pure Mo50Re and rare earth oxide-doped Mo50Re,produced by spark plasma sintering,was performed in Ringer's physiologic solution at a temperature of 37°C.Potentiodynamic polarization testing indicated a reduction in corrosion current density from 3.1μA·cm^(^(-2))for the pure Mo50Re to 1.6μA·cm^(-2)for Y-doped,1.5μA·cm^(-2)for La-doped,and 2.1μA·cm^(-2)for Y-La co-doped variants.Furthermore,electrochemical impedance spectroscopy revealed that the charge transfer resistance for the rare earth-doped alloys was higher,with values reaching up to 2.4×10^(4)Ω·cm2for Y-doped,3.4×10^(4)Ω·cm2for La-doped,and 2.9×10^(4)Ω·cm2for Y-La co-doped materials,in contrast to the 1.7×10^(3)Ω·cm2resistance observed for the pure Mo50Re.The research highlights the significant enhancement in corrosion resistance conferred by the incorporation of rare earth elements,ascribed to their ability to refine the grain size and purify the grain boundaries.展开更多
Aluminum doped zinc oxide （AZO）, as an electrically conductive material, was applied to coating on the surface of olivine-type LiFePO4 synthesized by solid-state method. The charge-discharge test results show that t...Aluminum doped zinc oxide （AZO）, as an electrically conductive material, was applied to coating on the surface of olivine-type LiFePO4 synthesized by solid-state method. The charge-discharge test results show that the rate performance and low-temperature performance of LiFePO4 are greatly improved by the surface treatment. Even at 20C rate, the discharge specific capacity of 100.9 mA.h/g was obtained by the AZO-coated LiFePO4 at room temperature. At -20 ℃, the discharge specific capacity at 0.2C for un-coated LiFePO4 and the coated one are 50.3 mA.h/g and 119.4 mA.h/g, respectively. It should be attributed to the electrically conductive AZO-coating which increases the electronic conductivity of LiFePO4. Furthermore, the surface-coating increases the tap-density of LiFePO4. The results indicate that the AZO-coated LiFePO4 is a good candidate of cathode material for applying in lithium power batteries.展开更多
The synthesis,crystal structure and electrical conductivity properties of Fe-doped ZnO powders（in the range of 0.25-15 mol%） were reported in this paper.I-phase samples,which were indexed as single phase with a hexa...The synthesis,crystal structure and electrical conductivity properties of Fe-doped ZnO powders（in the range of 0.25-15 mol%） were reported in this paper.I-phase samples,which were indexed as single phase with a hexagonal（wurtzite） structure in the Fe-doped ZnO binary system,were determined by X-ray diffraction（XRD）.The solubility limit of Fe in the ZnO lattice is 3 mol% at 950℃.The above mixed phase was observed.And the impurity phase was determined as the cubic-ZnFe 2 O 4 phase when compared with standard XRD data using the PDF program.This study focused on single I-phase ZnO samples which were synthesized at 950℃ because the limit of the solubility range is the widest at this temperature.The lattice parameters a and c of the I-phase decreased with Fe-doping concentration.The morphology of the I-phase samples was analyzed with a scanning electron microscope.The grain size of the I-phase samples increased with heat treatment and doping concentration.The electrical conductivity of the pure ZnO and single I-phase samples was investigated using the four-probe dc method at 100-950℃ in air atmosphere.The electrical conductivity values of pure ZnO,0.25 and 3 mol% Fe-doped ZnO samples at 100℃ were 2×10-6,1.7×10-3 and 6.3×10-4 S.cm-1,and at 950℃ they were 3.4,8.5 and 4 S.cm-1,respectively.展开更多
Cu-Ce-O catalysts, prepared by the amorphous citrate precursor (ACP) method, wereinvestigated by ICP, XRD and ndcro-reactor techniques. At low copper content of Cu-Ce-Ocatalysts, fluorite structures formed at low calc...Cu-Ce-O catalysts, prepared by the amorphous citrate precursor (ACP) method, wereinvestigated by ICP, XRD and ndcro-reactor techniques. At low copper content of Cu-Ce-Ocatalysts, fluorite structures formed at low calcining temperatures, and Cuo doped into the CeO2matrix; at high copper content, in addition to the fluorite structure, crystalline monoclinic phaseCuO formed as well at high calcining temperatures. There was no other phase formed even calcinedat 1000℃. The results show that only a little CuO dopes into the CeO2 matrix to form complexoxide, which promotes the catalytic activity of CO oxidation greatly. The optimum Cu-Ce-Ocatalyst is composed of 15% copper by Cu/(Ce+Cu) atomic ratio, and calcined at 700℃ for 4h. Thephase compositions include the crystalline CuO and the active complex oxide with fluoritestructure. The formulation of the active complex oxide is Cu0.06Ce0. 94O1.94.展开更多
In this study we used a chemical solution method from oxalic acid (OX. acid) and zinc acetate (ZnAc) to prepare Zinc Oxide nanoparticles (ZnONPs) and Zinc Oxide nanoparticles doped with Chlorine (Cl:ZnONPs). The chara...In this study we used a chemical solution method from oxalic acid (OX. acid) and zinc acetate (ZnAc) to prepare Zinc Oxide nanoparticles (ZnONPs) and Zinc Oxide nanoparticles doped with Chlorine (Cl:ZnONPs). The characterizations (FTIR, X-ray, SEM, TEM) of ZnONPs and Cl:ZnONPs were determined. Amylase inhibitors of ZnONPs and Cl:ZnONPs also were determined. SEM indicated that the ZnONPs and Cl:ZnONPs have an average particle size of 46.65 - 74.64 nm. TEM images of the ZnONPs and Cl:ZnONPs showed the round shaped. Compounds b,<span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">d and e exhibited significant inhibitory activity against amylase enzyme</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">(from 69.21</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">±</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">1.44 to 76.32</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">±</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">0.78), respectively, and were comparable with that of acarbose (86.32 ± 0.63) at 1000</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">μg, thereby, projecting ZnONPs and Cl:ZnONPs as </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-amylase inhibitors.</span></span></span></span>展开更多
Tin oxide（SnO2） and fluorine doped tin oxide（FTO） films were prepared on glass substrates by sol-gel spin-coating using SnCl4 and NH4F precursors.Fluorine doping concentration was fixed at 4 at%and 20 at%by contro...Tin oxide（SnO2） and fluorine doped tin oxide（FTO） films were prepared on glass substrates by sol-gel spin-coating using SnCl4 and NH4F precursors.Fluorine doping concentration was fixed at 4 at%and 20 at%by controlling precursor sol composition.Films exhibited the tetragonal rutile-type crystal structure regardless of fluorine concentration.Uniform and highly transparent FTO films,with more than 85%of optical transmittance,were obtained by annealing at 600℃.Florine doping of films was verified by analyzing the valence band region obtained by XPS.It was found that the fluorine doping affects the shape of valence band of SnO2 films.In addition,it was observed that the band gap of SnO2 is reduced as well as the Fermi level is upward shifted by the effect of fluorine doping.展开更多
High transparent and conductive thin films of zinc doped tin oxide （ZTO） were deposited on quartz substrates by the radio-frequency （RF） magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO2 ceramic targe...High transparent and conductive thin films of zinc doped tin oxide （ZTO） were deposited on quartz substrates by the radio-frequency （RF） magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO2 ceramic target.The effect of substrate temperature on the structural,electrical and optical performances of ZTO films has been studied.X-ray diffraction （XRD） results show that ZTO films possess tetragonal rutile structure with the preferred orientation of （101）.The surface morphology and roughness of the films was investigated by the atomic force microscope （AFM）.The electrical characteristic （including carrier concentration,Hall mobility and resistivity） and optical transmittance were studied by the Hall tester and UV- VIS,respectively.The highest carrier concentration of -1.144×1020 cm-3 and the Hall mobility of 7.018 cm2（V ·sec）-1 for the film with an average transmittance of about 80.0% in the visible region and the lowest resistivity of 1.116×10-2 Ω·cm were obtained when the ZTO films deposited at 250 oC.展开更多
This paper reported the synthesis, crystal structure and electrical conductivity properties of Ni-doped ZnO powders （i.e. Zn1-xNixO binary system, X=0, 0.0025, 0.005, 0.0075 and in the range 0.01≤X〈0.15）. I- phase...This paper reported the synthesis, crystal structure and electrical conductivity properties of Ni-doped ZnO powders （i.e. Zn1-xNixO binary system, X=0, 0.0025, 0.005, 0.0075 and in the range 0.01≤X〈0.15）. I- phase samples, which were indexed as single phase with a hexagonal （wurtzite） structure in the Zn1-xNixO binary system, were determined by X-ray diffraction （XRD）. The widest range of the I-phase was determined as 0≤X≤0.03 at 1200℃; above this range the mixed phase was observed. The impurity phase was determined as NiO when compared with standard XRD data, using the PDF program. We focused on single f-phase ZnO samples which were synthesized at 1200℃ because of the widest range of solubility limit at this temperature. It was observed that the lattice parameters a and c of the I-phase decreased with Ni doping concentration. The morphology of the I-phase samples was analyzed with a scanning electron microscope. The electrical conductivity of the pure ZnO and single I-phase samples were studied by using the four-probe dc method at temperatures between 100 and 950℃ in air atmosphere. The electrical conductivity values of pure ZnO and 3 mol% Ni-doped ZnO samples at 100℃C were 2×10^-6 and 4.8×10^-6 Ω-1.cm^-1, and at 950℃ they were 1.8 and 3.6 Ω-1cm-1, respectively. In other words, electrical conductivity increased with Ni doping concentration.展开更多
Utilizing single atom sites doping into metal oxides to modulate their intrinsic active sites,achieving precise selectivity control in complex organic reactions,is a highly desirable yet challenging endeavor.Meanwhile...Utilizing single atom sites doping into metal oxides to modulate their intrinsic active sites,achieving precise selectivity control in complex organic reactions,is a highly desirable yet challenging endeavor.Meanwhile,identifying the active site also represents a significant obstacle,primarily due to the intricate electronic environment of single atom site doped metal oxide.Herein,a single atom Cu doped TiO_(2)catalyst(Cu_(1)-TiO_(2)) is prepared via a simple“colloid-acid treatment”strategy,which switches aniline oxidation selectivity of TiO_(2) from azoxybenzene to nitrosobenzene,without using additives or changing solvent,while other metal or nonmetal doped TiO_(2) did not possess.Comprehensive mechanistic investigations and DFT calculations unveil that Ti-O active site is responsible for triggering the aniline to form a new PhNOH intermediate,two PhNOH condense to azoxybenzene over TiO_(2) catalyst.As for Cu_(1)-TiO_(2),the charge-specific distribution between the isolated Cu and TiO_(2) generates unique Cu_(1)-O-Ti hybridization structure with nine catalytic active sites,eight of them make PhNOH take place spontaneous dissociation to produce nitrosobenzene.This work not only unveils a new mechanistic pathway featuring the PhNOH intermediate in aniline oxidation for the first time but also presents a novel approach for constructing single-atom doped metal oxides and exploring their intricate active sites.展开更多
Perovskite solar cells(PSCs)have made great advances in terms of power conversion efficiency(PCE),yet their subpar stability continues to hinder their commercialization.The interface between the perovskite layer and t...Perovskite solar cells(PSCs)have made great advances in terms of power conversion efficiency(PCE),yet their subpar stability continues to hinder their commercialization.The interface between the perovskite layer and the charge-carrier transporting layers plays a crucial role in undermining the stability of PSCs.In this work,we propose a strategy to stabilize high-performance PSCs with PCE over 23%by introducing a cesium-doped graphene oxide(GO-Cs)as an interlayer between the perovskite and hole-transporting material.The GO-Cs treated PSCs exhibit excellent operational stability with a projected T80(the time where the device PCE reduces to 80%of its initial value)of 2143 h of operation at the maximum powering point under one sun illumination.展开更多
Indium doped zinc oxide （ZnO：In） thin films were prepared by ultrasonic spray pyrolysis on corning eagle 2000 glass substrate. 1 and 2 at.% indium doped single-layer ZnO：In thin films with different amounts of ace...Indium doped zinc oxide （ZnO：In） thin films were prepared by ultrasonic spray pyrolysis on corning eagle 2000 glass substrate. 1 and 2 at.% indium doped single-layer ZnO：In thin films with different amounts of acetic acid added in the initial solution were fabricated. The 1 at.% indium doped single-layers have triangle grains. The 2 at.% indium doped single-layer with 0.18 acetic acid adding has the resistivity of 6.82 × 10^-3 Ω. cm and particle grains. The doublelayers structure is designed to fabricate the ZnO：In thin film with low resistivity （2.58 × 10^-3 Ω. cm） and good surface morphology. It is found that the surface morphology of the double-layer ZnO：In film strongly depends on the substratelayer, and the second-layer plays a large part in the resistivity of the doublewlayer ZnO：In thin film. Both total and direct transmittances of the double-layer ZnO：In film are above 80% in the visible light region. Single junction a-Si：H solar cell based on the double-layer ZnO：In as front electrode is also investigated.展开更多
Via the first principles calculations, we predict that Cu doped graphene oxide （GO） is a much better nanocatalyst in terms of activity and feasibility. The high activity of Cu doped graphene oxides may be attributed...Via the first principles calculations, we predict that Cu doped graphene oxide （GO） is a much better nanocatalyst in terms of activity and feasibility. The high activity of Cu doped graphene oxides may be attributed to the charge transfer between the GO and Cu atom, resulting in an activated Cu atom. In the ER mechanism, the CO molecules directly react with the activated O2, then forming a metastable carbonate-like intermediate state （OOCO）. The reaction may proceed via two reaction paths of OOCO → CO2 ＋ O and CO ＋ OOCO → 2CO2, respectively. The calculated results show that the latter path is relatively more thermodynamically favorable with a modest energy barrier, so it should be more preferred. We expect our theoretical predictions to open a new avenue to fabricate carbon-based catalysts for CO oxidation with lower cost and higher activity.展开更多
Tin-doped Indium Oxide （ITO） has been successfully prepared via solvothermal method with a mixture of Indium（Ill） acetylacetonate and Tin（IV） bis（acetylacetonate）dichioride in oleyamine solvent under the condi...Tin-doped Indium Oxide （ITO） has been successfully prepared via solvothermal method with a mixture of Indium（Ill） acetylacetonate and Tin（IV） bis（acetylacetonate）dichioride in oleyamine solvent under the condition of the different reaction time from 12 h to 48 h for the first time. The morphology, phase composition and particle size of the ITO powder were characterized by TEM and XRD. Two significant properties required for ITO samples to become noncarbon support for Pt in PEMFCs including specific surface area and electrical conductivity were studied.展开更多
Cu(copper)-doped ZnO(zinc oxide)was synthesized using Cu(NO3)2·3H2O(copper(II)nitrate)and Zn(NO3)2·6H2O(zinc nitrate)by chemical co-precipitation method.The weight percentages of dopant in solution were Cu(2...Cu(copper)-doped ZnO(zinc oxide)was synthesized using Cu(NO3)2·3H2O(copper(II)nitrate)and Zn(NO3)2·6H2O(zinc nitrate)by chemical co-precipitation method.The weight percentages of dopant in solution were Cu(2,3,and 5 wt%).Cu-doped ZnO thin films were prepared on p-Si(100)substrate by screen printing method.Cu-doped ZnO/Si films were annealed at different temperatures from 300 to 700°C.In this study,Cu-doped ZnO structures were prepared by a simple precipitation technique,and characterized by various techniques such as XRD(X-ray diffraction)and SEM(scanning electron microscope).The electrical properties of Cu-doped ZnO/Si were measured.It has found that Cu-doped ZnO/Si films can be used as optoelectronic devices.展开更多
Samples doped with different amount of dysprosium oxide into barium strontium titanate (BSTO) were prepared. Dielectric properties of the samples at high frequency were discussed. X-ray diffraction (XRD) method was em...Samples doped with different amount of dysprosium oxide into barium strontium titanate (BSTO) were prepared. Dielectric properties of the samples at high frequency were discussed. X-ray diffraction (XRD) method was employed for analyzing and comparing with the changes in the crystal lattice of the samples,and information of crystal growth was obtained through method of environmental scanning electron micrograph (ESEM). Influence of dysprosium oxide doping on dielectric properties of BSTO based ceramic system at high frequency was studied. Phenomenological coefficients of the samples were calculated on the base of tunability.展开更多
Vertical ZnO nanotube （ZNT） arrays were synthesized onto an indium doped tin oxide （ITO） glass substrate by a simple electrochemical deposition technique followed by a selective etching process. Scanning electron ...Vertical ZnO nanotube （ZNT） arrays were synthesized onto an indium doped tin oxide （ITO） glass substrate by a simple electrochemical deposition technique followed by a selective etching process. Scanning electron microscopy （SEM） showed formation of well-faceted hexagonal ZNT arrays spreading uniformly over a large area. X-ray diffraction （XRD） of ZNT layer showed substantially higher intensity for the （0002） diffraction peak, indicating that the ZnO crystallites were well aligned with their c-axis. Profilometer measurements of the ZNT layer showed an average thickness of -7 μm. Diameter size distribution （DSD） analysis showed that ZNTs exhibited a narrow diameter size distribution in the range of 65-120 nm and centered at -75 nm. The photoluminescence （PL） spectrum measurement showed violet and blue luminescence peaks that were centered at 410 and 480 nm, respectively, indicating the presence of internal defects. Ultra-violet （UV） spectroscopy showed major absorbance peak at ,-348 nm, exhibiting an increase in energy gap value of 3.4 eV. By employing the formed ZNTs as the photo-anode for a dye-sensitized solar cell （DSSC）, a full-sun conversion efficiency of 1.01% was achieved with a fill factor of 54%. Quantum efficiency studies showed the maximum of incident photon-to-electron conversion efficiency in a visible region located at 590-550 nm range.展开更多
The Ti/SnO2-Sb-Mo electrodes doped with different molar ratios of molybdenum（Mo） were prepared by sol—gel method in order to investigate the effect of Mo on the characterization of Ti/SnO2-Sb—Mo electrodes.X-ray d...The Ti/SnO2-Sb-Mo electrodes doped with different molar ratios of molybdenum（Mo） were prepared by sol—gel method in order to investigate the effect of Mo on the characterization of Ti/SnO2-Sb—Mo electrodes.X-ray diffraction（XRD）,field-emission scanning electron microscopy（FE-SEM）,energy dispersive spectrometry（EDS）,and linear scanning voltammetry（LSV） were used to scrutinize the coating material and the electrochemical activity.The concentration of phenol,the value of total organic carbon（TOC）,the mineralization current efficiency（MCE） and the ultraviolet—visible spectroscopy（UV-Vis） spectrum of phenol solution were measured over the electrochemical degradation process of phenol to confirm the phenol degradation characterization of Ti/SnO2-Sb-Mo electrodes.Results showed that the electrode at the Mo content of 1 at.%provided optimal catalytic activity for phenol degradation and the longest life time.The removal percentage of phenol and TOC were 99.62%and82.67%,respectively.The Ti/SnO2-Sb-Mo electrode with 1 at.%of Mo reached maximum MCE of phenol oxidation.The kinetic investigation of phenol and TOC degradation displayed the pseudo-first order reaction model.The Ti/SnO2-Sb-Mo electrode coating with 7 at.%Mo presented the highest oxygen evolution overpotential,indicating the diverse effects for different Mo molar ratio doping.展开更多
The promising solar irradiated photocatalyst by pairing of bismuth oxide quantum dots(BQDs)doped TiO_(2)with nitrogen doped graphene oxide(NGO)nanocomposite(NGO/BQDs-TiO_(2))was fabricated.It was used for degradation ...The promising solar irradiated photocatalyst by pairing of bismuth oxide quantum dots(BQDs)doped TiO_(2)with nitrogen doped graphene oxide(NGO)nanocomposite(NGO/BQDs-TiO_(2))was fabricated.It was used for degradation of organic pollutants like 2,4-dichlorophenol(2,4-DCP)and stable dyes,i.e.Rhodamine B and Congo Red.X-ray diffraction(XRD)profile of NGO showed reduction in oxygenic functional groups and restoring of graphitic crystal structure.The characteristic diffraction peaks of TiO_(2)and its composites showed crystalline anatase TiO_(2).Morphological images represent spherical shaped TiO_(2)evenly covered with BQDs spread on NGO sheet.The surface linkages of NO-O-Ti,C-O-Ti,Bi-O-Ti and vibrational modes are observed by Fourier transform infrared spectroscopy(FTIR)and Raman studies.BQDs and NGO modified TiO_(2)results into red shifting in visible region as studied in diffused reflectance spectroscopy(DRS).NGO and BQDs in TiO_(2)are linked with defect centers which reduced the recombination of free charge carriers by quenching of photoluminescence(PL)intensities.X-ray photoelectron spectroscopy(XPS)shows that no peak related to C-O in NGO/BQDs-TiO_(2)is observed.This indicated that doping of nitrogen into GO has reduced some oxygen functional groups.Nitrogen functionalities in NGO and photosensitizing effect of BQDs in ternary composite have improved photocatalytic activity against organic pollutants.Intermediate byproducts during photo degradation process of 2,4-DCP were studied through high performance liquid chromatography(HPLC).Study of radical scavengers indicated that O_(2)^(·-) has significant role for degradation of 2,4-DCP.Our investigations propose that fabricated nanohybrid architecture has potential for degradation of environmental pollutions.展开更多
文摘Different amounts of dysprosium oxide were incorporated into barium titanate powders synthesized by hydrothermal method. Relations of substitution behaviors and lattice parameters with solid-solubility were studied. Furthermore, the influences of dysprosium oxide doping fraction on grain size and dielectric properties of barium titanate ceramic, including dielectric constant and breakdown electric field strength , were investigated via scanning electron microscope, X-ray diffraction and electric property tester. The results show that dysprosium oxide can restrain abnormal grain growth during sintering and that fine-grained and high density of barium titanate ceramic can result in excellent dielectric properties. As mass fraction of dysprosium oxide is 0.6%, the lattice parameters of grain increase to the maximum because of the lowest vacancy concentration. The electric property parameters are cited as following： dielectric constant （25 ℃ ） reaches 4100, the change in relative dielectric constant with temperature is - 10% to 10% within the range of - 15 - 100 ℃, breakdown electric field strength （alternating current） achieves 3.2 kV·mm^-1, which can be used in manufacturing high voltage ceramic capacitors
基金financial supported by the National Natural Science Foundation of China(No.52164043)Jiangxi Province Key Laboratory of Ultra-high Temperature Metal Material(2024SSY05011)。
文摘An investigation into the corrosion behavior of pure Mo50Re and rare earth oxide-doped Mo50Re,produced by spark plasma sintering,was performed in Ringer's physiologic solution at a temperature of 37°C.Potentiodynamic polarization testing indicated a reduction in corrosion current density from 3.1μA·cm^(^(-2))for the pure Mo50Re to 1.6μA·cm^(-2)for Y-doped,1.5μA·cm^(-2)for La-doped,and 2.1μA·cm^(-2)for Y-La co-doped variants.Furthermore,electrochemical impedance spectroscopy revealed that the charge transfer resistance for the rare earth-doped alloys was higher,with values reaching up to 2.4×10^(4)Ω·cm2for Y-doped,3.4×10^(4)Ω·cm2for La-doped,and 2.9×10^(4)Ω·cm2for Y-La co-doped materials,in contrast to the 1.7×10^(3)Ω·cm2resistance observed for the pure Mo50Re.The research highlights the significant enhancement in corrosion resistance conferred by the incorporation of rare earth elements,ascribed to their ability to refine the grain size and purify the grain boundaries.
文摘Aluminum doped zinc oxide （AZO）, as an electrically conductive material, was applied to coating on the surface of olivine-type LiFePO4 synthesized by solid-state method. The charge-discharge test results show that the rate performance and low-temperature performance of LiFePO4 are greatly improved by the surface treatment. Even at 20C rate, the discharge specific capacity of 100.9 mA.h/g was obtained by the AZO-coated LiFePO4 at room temperature. At -20 ℃, the discharge specific capacity at 0.2C for un-coated LiFePO4 and the coated one are 50.3 mA.h/g and 119.4 mA.h/g, respectively. It should be attributed to the electrically conductive AZO-coating which increases the electronic conductivity of LiFePO4. Furthermore, the surface-coating increases the tap-density of LiFePO4. The results indicate that the AZO-coated LiFePO4 is a good candidate of cathode material for applying in lithium power batteries.
基金supported by the Research Foundation of Erciyes University (Kayseri,Turkey)
文摘The synthesis,crystal structure and electrical conductivity properties of Fe-doped ZnO powders（in the range of 0.25-15 mol%） were reported in this paper.I-phase samples,which were indexed as single phase with a hexagonal（wurtzite） structure in the Fe-doped ZnO binary system,were determined by X-ray diffraction（XRD）.The solubility limit of Fe in the ZnO lattice is 3 mol% at 950℃.The above mixed phase was observed.And the impurity phase was determined as the cubic-ZnFe 2 O 4 phase when compared with standard XRD data using the PDF program.This study focused on single I-phase ZnO samples which were synthesized at 950℃ because the limit of the solubility range is the widest at this temperature.The lattice parameters a and c of the I-phase decreased with Fe-doping concentration.The morphology of the I-phase samples was analyzed with a scanning electron microscope.The grain size of the I-phase samples increased with heat treatment and doping concentration.The electrical conductivity of the pure ZnO and single I-phase samples was investigated using the four-probe dc method at 100-950℃ in air atmosphere.The electrical conductivity values of pure ZnO,0.25 and 3 mol% Fe-doped ZnO samples at 100℃ were 2×10-6,1.7×10-3 and 6.3×10-4 S.cm-1,and at 950℃ they were 3.4,8.5 and 4 S.cm-1,respectively.
文摘Cu-Ce-O catalysts, prepared by the amorphous citrate precursor (ACP) method, wereinvestigated by ICP, XRD and ndcro-reactor techniques. At low copper content of Cu-Ce-Ocatalysts, fluorite structures formed at low calcining temperatures, and Cuo doped into the CeO2matrix; at high copper content, in addition to the fluorite structure, crystalline monoclinic phaseCuO formed as well at high calcining temperatures. There was no other phase formed even calcinedat 1000℃. The results show that only a little CuO dopes into the CeO2 matrix to form complexoxide, which promotes the catalytic activity of CO oxidation greatly. The optimum Cu-Ce-Ocatalyst is composed of 15% copper by Cu/(Ce+Cu) atomic ratio, and calcined at 700℃ for 4h. Thephase compositions include the crystalline CuO and the active complex oxide with fluoritestructure. The formulation of the active complex oxide is Cu0.06Ce0. 94O1.94.
文摘In this study we used a chemical solution method from oxalic acid (OX. acid) and zinc acetate (ZnAc) to prepare Zinc Oxide nanoparticles (ZnONPs) and Zinc Oxide nanoparticles doped with Chlorine (Cl:ZnONPs). The characterizations (FTIR, X-ray, SEM, TEM) of ZnONPs and Cl:ZnONPs were determined. Amylase inhibitors of ZnONPs and Cl:ZnONPs also were determined. SEM indicated that the ZnONPs and Cl:ZnONPs have an average particle size of 46.65 - 74.64 nm. TEM images of the ZnONPs and Cl:ZnONPs showed the round shaped. Compounds b,<span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">d and e exhibited significant inhibitory activity against amylase enzyme</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">(from 69.21</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">±</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">1.44 to 76.32</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">±</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">0.78), respectively, and were comparable with that of acarbose (86.32 ± 0.63) at 1000</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">μg, thereby, projecting ZnONPs and Cl:ZnONPs as </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-amylase inhibitors.</span></span></span></span>
文摘Tin oxide（SnO2） and fluorine doped tin oxide（FTO） films were prepared on glass substrates by sol-gel spin-coating using SnCl4 and NH4F precursors.Fluorine doping concentration was fixed at 4 at%and 20 at%by controlling precursor sol composition.Films exhibited the tetragonal rutile-type crystal structure regardless of fluorine concentration.Uniform and highly transparent FTO films,with more than 85%of optical transmittance,were obtained by annealing at 600℃.Florine doping of films was verified by analyzing the valence band region obtained by XPS.It was found that the fluorine doping affects the shape of valence band of SnO2 films.In addition,it was observed that the band gap of SnO2 is reduced as well as the Fermi level is upward shifted by the effect of fluorine doping.
基金Funded by the Program for Changjiang Scholars and Innovative Research Team in University, Ministry of Education, China (No.IRT0547)
文摘High transparent and conductive thin films of zinc doped tin oxide （ZTO） were deposited on quartz substrates by the radio-frequency （RF） magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO2 ceramic target.The effect of substrate temperature on the structural,electrical and optical performances of ZTO films has been studied.X-ray diffraction （XRD） results show that ZTO films possess tetragonal rutile structure with the preferred orientation of （101）.The surface morphology and roughness of the films was investigated by the atomic force microscope （AFM）.The electrical characteristic （including carrier concentration,Hall mobility and resistivity） and optical transmittance were studied by the Hall tester and UV- VIS,respectively.The highest carrier concentration of -1.144×1020 cm-3 and the Hall mobility of 7.018 cm2（V ·sec）-1 for the film with an average transmittance of about 80.0% in the visible region and the lowest resistivity of 1.116×10-2 Ω·cm were obtained when the ZTO films deposited at 250 oC.
基金supported by the Research Foundation of Erciyes University (Kayseri,Turkey)
文摘This paper reported the synthesis, crystal structure and electrical conductivity properties of Ni-doped ZnO powders （i.e. Zn1-xNixO binary system, X=0, 0.0025, 0.005, 0.0075 and in the range 0.01≤X〈0.15）. I- phase samples, which were indexed as single phase with a hexagonal （wurtzite） structure in the Zn1-xNixO binary system, were determined by X-ray diffraction （XRD）. The widest range of the I-phase was determined as 0≤X≤0.03 at 1200℃; above this range the mixed phase was observed. The impurity phase was determined as NiO when compared with standard XRD data, using the PDF program. We focused on single f-phase ZnO samples which were synthesized at 1200℃ because of the widest range of solubility limit at this temperature. It was observed that the lattice parameters a and c of the I-phase decreased with Ni doping concentration. The morphology of the I-phase samples was analyzed with a scanning electron microscope. The electrical conductivity of the pure ZnO and single I-phase samples were studied by using the four-probe dc method at temperatures between 100 and 950℃ in air atmosphere. The electrical conductivity values of pure ZnO and 3 mol% Ni-doped ZnO samples at 100℃C were 2×10^-6 and 4.8×10^-6 Ω-1.cm^-1, and at 950℃ they were 1.8 and 3.6 Ω-1cm-1, respectively. In other words, electrical conductivity increased with Ni doping concentration.
文摘Utilizing single atom sites doping into metal oxides to modulate their intrinsic active sites,achieving precise selectivity control in complex organic reactions,is a highly desirable yet challenging endeavor.Meanwhile,identifying the active site also represents a significant obstacle,primarily due to the intricate electronic environment of single atom site doped metal oxide.Herein,a single atom Cu doped TiO_(2)catalyst(Cu_(1)-TiO_(2)) is prepared via a simple“colloid-acid treatment”strategy,which switches aniline oxidation selectivity of TiO_(2) from azoxybenzene to nitrosobenzene,without using additives or changing solvent,while other metal or nonmetal doped TiO_(2) did not possess.Comprehensive mechanistic investigations and DFT calculations unveil that Ti-O active site is responsible for triggering the aniline to form a new PhNOH intermediate,two PhNOH condense to azoxybenzene over TiO_(2) catalyst.As for Cu_(1)-TiO_(2),the charge-specific distribution between the isolated Cu and TiO_(2) generates unique Cu_(1)-O-Ti hybridization structure with nine catalytic active sites,eight of them make PhNOH take place spontaneous dissociation to produce nitrosobenzene.This work not only unveils a new mechanistic pathway featuring the PhNOH intermediate in aniline oxidation for the first time but also presents a novel approach for constructing single-atom doped metal oxides and exploring their intricate active sites.
基金King Abdulaziz City for Science and Technology (KACST) for the fellowshipfunding from the European Union’s Horizon 2020 research and innovation program GRAPHENE Flagship Core 3 under agreement No.: 881603+2 种基金funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sk?odowska-Curie grant agreement No. 945363funding from the Shanghai Pujiang Program (22PJ1401200)the National Natural Science Foundation of China (No. 52302229)
文摘Perovskite solar cells(PSCs)have made great advances in terms of power conversion efficiency(PCE),yet their subpar stability continues to hinder their commercialization.The interface between the perovskite layer and the charge-carrier transporting layers plays a crucial role in undermining the stability of PSCs.In this work,we propose a strategy to stabilize high-performance PSCs with PCE over 23%by introducing a cesium-doped graphene oxide(GO-Cs)as an interlayer between the perovskite and hole-transporting material.The GO-Cs treated PSCs exhibit excellent operational stability with a projected T80(the time where the device PCE reduces to 80%of its initial value)of 2143 h of operation at the maximum powering point under one sun illumination.
基金supported by Hi-Tech Research and Development Program of China (Grant Nos. 2007AA05Z436 and 2009AA050602)Science and Technology Support Project of Tianjin (Grant No. 08ZCKFGX03500)+3 种基金the National Basic Research Program of China (Grant Nos. 2011CB201605 and 2011CB201606)the National Natural Science Foundation of China (Grant No. 60976051)International Cooperation Project between China-Greece Government (Grant No. 2009DFA62580)Program for New Century Excellent Talents in University of China (Grant No. NCET-08-0295)
文摘Indium doped zinc oxide （ZnO：In） thin films were prepared by ultrasonic spray pyrolysis on corning eagle 2000 glass substrate. 1 and 2 at.% indium doped single-layer ZnO：In thin films with different amounts of acetic acid added in the initial solution were fabricated. The 1 at.% indium doped single-layers have triangle grains. The 2 at.% indium doped single-layer with 0.18 acetic acid adding has the resistivity of 6.82 × 10^-3 Ω. cm and particle grains. The doublelayers structure is designed to fabricate the ZnO：In thin film with low resistivity （2.58 × 10^-3 Ω. cm） and good surface morphology. It is found that the surface morphology of the double-layer ZnO：In film strongly depends on the substratelayer, and the second-layer plays a large part in the resistivity of the doublewlayer ZnO：In thin film. Both total and direct transmittances of the double-layer ZnO：In film are above 80% in the visible light region. Single junction a-Si：H solar cell based on the double-layer ZnO：In as front electrode is also investigated.
基金supported by the National Natural Science Foundation of China(No.21004009)the Foundation of Jiangxi Educational Committee(No.GJJ14485)
文摘Via the first principles calculations, we predict that Cu doped graphene oxide （GO） is a much better nanocatalyst in terms of activity and feasibility. The high activity of Cu doped graphene oxides may be attributed to the charge transfer between the GO and Cu atom, resulting in an activated Cu atom. In the ER mechanism, the CO molecules directly react with the activated O2, then forming a metastable carbonate-like intermediate state （OOCO）. The reaction may proceed via two reaction paths of OOCO → CO2 ＋ O and CO ＋ OOCO → 2CO2, respectively. The calculated results show that the latter path is relatively more thermodynamically favorable with a modest energy barrier, so it should be more preferred. We expect our theoretical predictions to open a new avenue to fabricate carbon-based catalysts for CO oxidation with lower cost and higher activity.
文摘Tin-doped Indium Oxide （ITO） has been successfully prepared via solvothermal method with a mixture of Indium（Ill） acetylacetonate and Tin（IV） bis（acetylacetonate）dichioride in oleyamine solvent under the condition of the different reaction time from 12 h to 48 h for the first time. The morphology, phase composition and particle size of the ITO powder were characterized by TEM and XRD. Two significant properties required for ITO samples to become noncarbon support for Pt in PEMFCs including specific surface area and electrical conductivity were studied.
文摘Cu(copper)-doped ZnO(zinc oxide)was synthesized using Cu(NO3)2·3H2O(copper(II)nitrate)and Zn(NO3)2·6H2O(zinc nitrate)by chemical co-precipitation method.The weight percentages of dopant in solution were Cu(2,3,and 5 wt%).Cu-doped ZnO thin films were prepared on p-Si(100)substrate by screen printing method.Cu-doped ZnO/Si films were annealed at different temperatures from 300 to 700°C.In this study,Cu-doped ZnO structures were prepared by a simple precipitation technique,and characterized by various techniques such as XRD(X-ray diffraction)and SEM(scanning electron microscope).The electrical properties of Cu-doped ZnO/Si were measured.It has found that Cu-doped ZnO/Si films can be used as optoelectronic devices.
文摘Samples doped with different amount of dysprosium oxide into barium strontium titanate (BSTO) were prepared. Dielectric properties of the samples at high frequency were discussed. X-ray diffraction (XRD) method was employed for analyzing and comparing with the changes in the crystal lattice of the samples,and information of crystal growth was obtained through method of environmental scanning electron micrograph (ESEM). Influence of dysprosium oxide doping on dielectric properties of BSTO based ceramic system at high frequency was studied. Phenomenological coefficients of the samples were calculated on the base of tunability.
基金Department of Science and Technology (DST), Government of India was gratefully acknowledged for their financial support under the NATAG program monitored by Dr. G. Sundararajan
文摘Vertical ZnO nanotube （ZNT） arrays were synthesized onto an indium doped tin oxide （ITO） glass substrate by a simple electrochemical deposition technique followed by a selective etching process. Scanning electron microscopy （SEM） showed formation of well-faceted hexagonal ZNT arrays spreading uniformly over a large area. X-ray diffraction （XRD） of ZNT layer showed substantially higher intensity for the （0002） diffraction peak, indicating that the ZnO crystallites were well aligned with their c-axis. Profilometer measurements of the ZNT layer showed an average thickness of -7 μm. Diameter size distribution （DSD） analysis showed that ZNTs exhibited a narrow diameter size distribution in the range of 65-120 nm and centered at -75 nm. The photoluminescence （PL） spectrum measurement showed violet and blue luminescence peaks that were centered at 410 and 480 nm, respectively, indicating the presence of internal defects. Ultra-violet （UV） spectroscopy showed major absorbance peak at ,-348 nm, exhibiting an increase in energy gap value of 3.4 eV. By employing the formed ZNTs as the photo-anode for a dye-sensitized solar cell （DSSC）, a full-sun conversion efficiency of 1.01% was achieved with a fill factor of 54%. Quantum efficiency studies showed the maximum of incident photon-to-electron conversion efficiency in a visible region located at 590-550 nm range.
基金financial support from the China Environmental Protection Foundation,Geping Green ActionLiaoning Environmental Research and Education Fund "123 Project"(Grant No.CEPF2012-123-2-10)
文摘The Ti/SnO2-Sb-Mo electrodes doped with different molar ratios of molybdenum（Mo） were prepared by sol—gel method in order to investigate the effect of Mo on the characterization of Ti/SnO2-Sb—Mo electrodes.X-ray diffraction（XRD）,field-emission scanning electron microscopy（FE-SEM）,energy dispersive spectrometry（EDS）,and linear scanning voltammetry（LSV） were used to scrutinize the coating material and the electrochemical activity.The concentration of phenol,the value of total organic carbon（TOC）,the mineralization current efficiency（MCE） and the ultraviolet—visible spectroscopy（UV-Vis） spectrum of phenol solution were measured over the electrochemical degradation process of phenol to confirm the phenol degradation characterization of Ti/SnO2-Sb-Mo electrodes.Results showed that the electrode at the Mo content of 1 at.%provided optimal catalytic activity for phenol degradation and the longest life time.The removal percentage of phenol and TOC were 99.62%and82.67%,respectively.The Ti/SnO2-Sb-Mo electrode with 1 at.%of Mo reached maximum MCE of phenol oxidation.The kinetic investigation of phenol and TOC degradation displayed the pseudo-first order reaction model.The Ti/SnO2-Sb-Mo electrode coating with 7 at.%Mo presented the highest oxygen evolution overpotential,indicating the diverse effects for different Mo molar ratio doping.
基金International Islamic UniversityPakistan Institute of Engineering and Applied Sciences+1 种基金Higher Education Commission of Pakistan(NRPU grant No.3660)Aalto University Finland。
文摘The promising solar irradiated photocatalyst by pairing of bismuth oxide quantum dots(BQDs)doped TiO_(2)with nitrogen doped graphene oxide(NGO)nanocomposite(NGO/BQDs-TiO_(2))was fabricated.It was used for degradation of organic pollutants like 2,4-dichlorophenol(2,4-DCP)and stable dyes,i.e.Rhodamine B and Congo Red.X-ray diffraction(XRD)profile of NGO showed reduction in oxygenic functional groups and restoring of graphitic crystal structure.The characteristic diffraction peaks of TiO_(2)and its composites showed crystalline anatase TiO_(2).Morphological images represent spherical shaped TiO_(2)evenly covered with BQDs spread on NGO sheet.The surface linkages of NO-O-Ti,C-O-Ti,Bi-O-Ti and vibrational modes are observed by Fourier transform infrared spectroscopy(FTIR)and Raman studies.BQDs and NGO modified TiO_(2)results into red shifting in visible region as studied in diffused reflectance spectroscopy(DRS).NGO and BQDs in TiO_(2)are linked with defect centers which reduced the recombination of free charge carriers by quenching of photoluminescence(PL)intensities.X-ray photoelectron spectroscopy(XPS)shows that no peak related to C-O in NGO/BQDs-TiO_(2)is observed.This indicated that doping of nitrogen into GO has reduced some oxygen functional groups.Nitrogen functionalities in NGO and photosensitizing effect of BQDs in ternary composite have improved photocatalytic activity against organic pollutants.Intermediate byproducts during photo degradation process of 2,4-DCP were studied through high performance liquid chromatography(HPLC).Study of radical scavengers indicated that O_(2)^(·-) has significant role for degradation of 2,4-DCP.Our investigations propose that fabricated nanohybrid architecture has potential for degradation of environmental pollutions.
