The average thickncss of the interface layer wrapped about sols usually is determined by fitling the Porod curve that shuws anegative deviation from Porod's law.In this paper we show.that it could also be determin...The average thickncss of the interface layer wrapped about sols usually is determined by fitling the Porod curve that shuws anegative deviation from Porod's law.In this paper we show.that it could also be determined by a new method that includes the ful-lowing steps;(1)determining the average radius R,of the sol particles ineluding intlerface layer from the small angle X-ray scat-lering data in which shows negalive deviation from Porod's law;(2)detemining the average rardius R2 of the sol particlks not in-cluding the interface layer from the seattering daia in which las been correeted the negative deviation from P'orod'a law;(3)thedifference AR Lelwcen R1 and R2,i.e,AR=R1-R2,is just the average thieknoss of thr intcrfuce layer wrapperd alunt swuls,By using tlhe:above methol,the average thickness of tie interface layer wrapped about SiO2 wols prepared under dilferent runli-tions were determined.展开更多
Insulating parts are easily subjected to pollution which may cause damage to the electric system. A typical disc insulator is chosen as the target to test its flashover voltage by using an artificial pollution system....Insulating parts are easily subjected to pollution which may cause damage to the electric system. A typical disc insulator is chosen as the target to test its flashover voltage by using an artificial pollution system. This test system aims at obtaining characteristic parameters of damage for chosen conducting sola to the selected insulator. Experimental results show that thickness and electric conductivity of pollutant layer over insulators are the main parameters in damage evaluation. The flashover voltage decreases with increase of thickness and/or conductivity. These results provide a better basis on further revealing the damaging nature of conducting sol materials.展开更多
Cr2O3 has eminent slag corrosion resistance. So, the magnesite -chrome brick is thought as an important refractory material used in RH refining furnace in the process of steel-making around the world. After chromebear...Cr2O3 has eminent slag corrosion resistance. So, the magnesite -chrome brick is thought as an important refractory material used in RH refining furnace in the process of steel-making around the world. After chromebearing sols being prepared by sol-gel method, single sol （ Cr（ OH）3） and mixed sol （ Mg（ OH）2 - Cr（ OH）3） were impregnated into magnesite - chrome bricks by vacuum impregnation. The corrosion resistance of the impregnated bricks to silicon steel slag was studied by porosimetric analysis and fractal dimension calculation. The results showed that the corrosion resistance of impregnated magnesite -chrome brick was better than that of the unimpregnated brick and the brick impregnated by MgSO4 solution, and the one which has surface-treated by Mg（ OH）2 -Cr（OH）3 sol was the best, mainly because of lower apparent porosity, smaller pores diameter and their smoother inner sarface.展开更多
The TiO2, MoO3, PEO doped four-member tungstic acid sols were prepared for the first time. The stability of different doped content sols were investigated and optimized with rotational viscometer. The four-member dope...The TiO2, MoO3, PEO doped four-member tungstic acid sols were prepared for the first time. The stability of different doped content sols were investigated and optimized with rotational viscometer. The four-member doped tungstic acid sol was very stable which could be stored more than two months at room temperature. The WO3 electrochromic film prepared from this doped four- member tungstic acid sol had excellent performance and longevity of service.展开更多
Alumina sols with a molar ratio of 1 ： 50 between aluminum sec-batoxide（ ASB ） aud H2 O were fabricated by adding various amounts of nitric acid. The particle shape, zeta potential, polydispersity and effective par...Alumina sols with a molar ratio of 1 ： 50 between aluminum sec-batoxide（ ASB ） aud H2 O were fabricated by adding various amounts of nitric acid. The particle shape, zeta potential, polydispersity and effective particle size of alumina sol were examined by a TEM, a zeta PALS granularity analyzer and a zetaPALS zeta potential analyzer, respectively. By analyzing the change of zeta potential and doable-layer thickness with nitric acid concentration, the potential energy curves of colloidal particles were mapped on the basis of DLVO theory, and the effects of nitric acid concentration on the stability of alumina sols were intensively studied. The results show that for the alumina sols with a mol ratio of 1 ： 50 between ASB and H2O, the total interaction energy of the colloidal particle is at a maximum when the nitric acid concentration is 0.22 mol/ L. Therefore, the stability of the colloid reaches optimum at the nitric acid concentration of 0.22 mol / L.展开更多
The effects of liquid-solid ratio and reaction time on the leaching rate of magnesium at room temperature were investigated,as well as the effects of the molar ratio of MgO/MgCl_(2),the amount of water added,and the a...The effects of liquid-solid ratio and reaction time on the leaching rate of magnesium at room temperature were investigated,as well as the effects of the molar ratio of MgO/MgCl_(2),the amount of water added,and the amount of acid-impregnated slag dosed on the compressive strength and water resistance of LR-MOC.The results showed that the magnesium element in the boron mud could be maximally leached under the conditions of 1:1 concentration of hydrochloric acid at room temperature,liquid-solid ratio of 2.5 mL·g^(-1),and reaction time of 5 h,and the main products were amorphous SiO_(2) as well as a small amount of magnesium olivine which had not been completely reacted.The LR-MOC prepared using the acid-soaked mixture could reach a softening coefficient of 0.85 for 28 d of water immersion when the molar ratio of MgO/MgCl_(2) was 2.2,the amount of water added was 0 g,and the acid-soaked slag dosing was 40 wt%,which also led to an appreciable late-strength,with an increase of 19.4%in compressive strength at 28 d compared to that at 7 d.Unlike previous studies,LR-MOC prepared in this way has a final strength phase that is not the more easily hydrolysed 3-phase but the lath-like 5-phase.For this phenomenon,we analyzed the mechanism and found that,during the acid leaching process,a part of amorphous SiO_(2) dissolved in the acid leaching solution formed a silica sol,in which Mg^(2+)played a bridging role to make the silica sol more stable.With the addition and hydrolysis of MgO,the silica sol gel coagulation slows down,providing a capping layer to inhibit the hydrolysis of the 5-phase crystals and providing some strength after coagulation.The amorphous SiO_(2) in the other part of the acid-impregnated slag generated M-S-H gel with Mg^(2+)and OH-,which synergised with the dense structure composed of interlocking crystals to improve the water resistance of LR-MOC.展开更多
Cu_(2)ZnSnSSe_(4)(CZTSSe)thin film solar cells,with adjustable bandgap and rich elemental content,hold promise in next-gen photovoltaics.Crystalline quality is pivotal for efficient light absorption and carrier transp...Cu_(2)ZnSnSSe_(4)(CZTSSe)thin film solar cells,with adjustable bandgap and rich elemental content,hold promise in next-gen photovoltaics.Crystalline quality is pivotal for efficient light absorption and carrier transport.During the post-selenization process,understanding crystal growth mechanisms,and improving layer quality are essential.We explored the effects of ramp rate and annealing temperature on CZTSSe films,using X-ray diffraction(XRD),Raman spectroscopy,scanning electron microscope(SEM),and ultraviolet-visual spectrophotometry(UV-Vis).The optimal performance occurred at 25.25°C/min ramp rate and 530°C annealing.This led to smoother surfaces,higher density,and larger grains.This condition produced a single-layer structure with large grains,no secondary phases,and a 1.14 eV bandgap,making it promising for photovoltaic applications.The study has highlighted the effect of selenization conditions on the characteristics of the CZTSSe absorber layer and has provided valuable information for developing CZTSSe thin film solar cells.展开更多
The lining materials for blast furnaces have evolved from brick masonry to monolithic refractory materials.Monolithic castables are widely used in various industrial furnaces.The rapid development of silica sol materi...The lining materials for blast furnaces have evolved from brick masonry to monolithic refractory materials.Monolithic castables are widely used in various industrial furnaces.The rapid development of silica sol materials,combined with the commonly used construction methods of casting and spraying,offers greater flexibility,efficiency,environmental friendliness,and a longer lifespan.Typical monolithic refractory technologies,such as the integral casting technique for the furnace hearth,the pre-applied slag coating technique for the furnace belly and waist,and the inner lining gunning technique,are grounded in scientific theory and practice,thereby advancing the development of refractory materials and enhancing the operational quality of blast furnaces.展开更多
Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resi...Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resin composites.The influences of the SiB_(6)/SiO_(2)mixed modification on silica fiber properties were analyzed through thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and X-ray diffraction(XRD),respectively.Additionally,the influence of the SiB_(6)/SiO_(2)mixed modification on the mechanical properties of phenolic resin matrix composites was evaluated through mechanical testing.The experimeatal results indicate that the SiB_(6)/SiO_(2)mixed surface modification shows significant improvement in strength at room temperature and high temperatures,and crystallization temperature of silica fiber increases.The SiB_(6)/Silica sol co-modified silica fiber shows potential for future application in thermal protection and other high-temperature conditions.展开更多
This study successfully developed a series of carbon-sol-reinforced copper(Cu-CS)composite coatings by electrodeposition employing a superiorly dispersed carbon sol(CS)to avoid nanoparticle aggregation.The CS,characte...This study successfully developed a series of carbon-sol-reinforced copper(Cu-CS)composite coatings by electrodeposition employing a superiorly dispersed carbon sol(CS)to avoid nanoparticle aggregation.The CS,characterized using transmission electron microscopy and zeta potential analysis,consisted of carbon particles with an approximate diameter of 300 nm uniformly distributed in the electrolytes.The characteristics of the composite coatings were examined via scanning electron microscopy to observe its microstructures,X-ray diffraction to detect its phase constituents,and durability testing to determine the wear and corrosion resistance.Results indicated a significant improvement in coating thickness,density,and uniformity achieved for the Cu-CS composite coating with the addition of 20m L/L CS.Moreover,the Cu-CS composite coating exhibited a low wear volume(1.15×10^(-3)mm^(3)),a high hardness(HV_(0.5)137.1),and a low corrosion rate(0.191 mm/a).The significant contribution of carbon particles to the improvement of coating performance is mainly influenced by two factors,namely,the strengthening and lubricating effects resulting from the incorporated carbon particles.Nevertheless,overdosage of CS can compromise the microstructure of the Cu-CS composite coating,creating defects and undermining its functionality.展开更多
Founded in 2016,Zhejiang Haiyin Digital Technology Co.,Ltd.stands at the forefront of innovation as a certified China National High-Tech Enterprise,relentlessly advancing the boundaries of single-pass digital printing...Founded in 2016,Zhejiang Haiyin Digital Technology Co.,Ltd.stands at the forefront of innovation as a certified China National High-Tech Enterprise,relentlessly advancing the boundaries of single-pass digital printing technology.Our crowning achievement—the revolutionary KUNR High-Speed Digital Printing System—earned China’s prestigious National First-in-Kind Certification.Engineered with 100%independent patents across mechanical,control,software,ink supply,and inks,we deliver tailored intelligent turnkey solutions that transform textile production dynamics.展开更多
In order to restrain the huge volume expansion of bismuth(Bi)anodes in sodium ion batteries(SIBs),the core-shell structure Bi@mesoporous carbon nanospheres(Bi@mC)composite was designed and prepared by sol-gel method c...In order to restrain the huge volume expansion of bismuth(Bi)anodes in sodium ion batteries(SIBs),the core-shell structure Bi@mesoporous carbon nanospheres(Bi@mC)composite was designed and prepared by sol-gel method coupled heat treatment.Structural characterization displays that the average diameter of the as-prepared Bi@mC composites is about 200 nm and thickness of the N-doped mesoporous carbon shells is 20-30 nm.Electrochemical test and kinetic analysis results show that the mesoporous carbon shell can not only effectively relieve the stress caused by volume expansion of Bi and protect active material from pulverization caused by the stress during charging/discharging process,but also facilitate quick diffusion of sodium ions,thus improving rate and cycling performance.Bi@mC delivers a high specific capacity of 279 mA·h/g and a capacity retention of 97.6%after 3500 cycles at a current density of 5 A/g.Even at a high current density of 20 A/g,Bi@mC can still maintain a high specific capacity of 266 mA·h/g.Additionally,the Bi@mC//NVP full button sodium-ion batteries(SIBs)assembled using Bi@mC anode and Na_(3)V_(2)(PO_(4))_(3)(NVP)cathode deliver an energy density of 182 W·h/kg.展开更多
Rare earth metals and transition metals co-substitution have been shown to tailor the physical properties of BiFeO_(3).In this work,a series of Bi_(1-x)RE_(x)Fe_(1-x)Zr_(x)O_(3)(RE=La,Pr,Nd,Sm;x=0.00,0.03,0.06)multife...Rare earth metals and transition metals co-substitution have been shown to tailor the physical properties of BiFeO_(3).In this work,a series of Bi_(1-x)RE_(x)Fe_(1-x)Zr_(x)O_(3)(RE=La,Pr,Nd,Sm;x=0.00,0.03,0.06)multiferroic ferrites was synthesized using the sol-gel method.To gain comprehensive insights into these materials,we employed a range of characterization techniques,including X-ray diffraction,Raman and Fourier transform infrared spectroscopies,field emission scanning electron microscopy,UV-Vis spectroscopy,and a vibrating sample magnetometer.Our analysis reveals a rhombohedral crystal structure(R3c space group)for the synthesized ferrites.Notably,we observe a substantial decrease in the optical band gap as the RE/Zr co-substitution increases.Further investigation into the magnetic properties shows a remarkable transition from antiferromagnetic to ferromagnetic behavior,which we attribute to the disruption of the long-range periodicity of the spin cycloid and 4f-3d orbital interactions.In addition,we tested the photocatalytic performance of the RE/Zr co-substituted BiFeO_(3)nanoparticles for the degradation of methyl orange dye under sunlight.The results are quite impressive,with degradation efficiency reaching up to 100%at 40 min by the Bi_(1-x)RE_(x)Fe_(1-x)Zr_(x)O_(3)(RE=La,Sm).Overall,our study demonstrates the vast potential of Bi_(1-x)RE_(x)Fe_(1-x)Zr_(x)O_(3)ferrites in various fields,including optics,magnetism,water treatment,and environmental preservation.展开更多
文摘The average thickncss of the interface layer wrapped about sols usually is determined by fitling the Porod curve that shuws anegative deviation from Porod's law.In this paper we show.that it could also be determined by a new method that includes the ful-lowing steps;(1)determining the average radius R,of the sol particles ineluding intlerface layer from the small angle X-ray scat-lering data in which shows negalive deviation from Porod's law;(2)detemining the average rardius R2 of the sol particlks not in-cluding the interface layer from the seattering daia in which las been correeted the negative deviation from P'orod'a law;(3)thedifference AR Lelwcen R1 and R2,i.e,AR=R1-R2,is just the average thieknoss of thr intcrfuce layer wrapperd alunt swuls,By using tlhe:above methol,the average thickness of tie interface layer wrapped about SiO2 wols prepared under dilferent runli-tions were determined.
基金Sponsored by State Key Laboratory of Explosion Science and Technology Research Foundation (ZDKT08-04)
文摘Insulating parts are easily subjected to pollution which may cause damage to the electric system. A typical disc insulator is chosen as the target to test its flashover voltage by using an artificial pollution system. This test system aims at obtaining characteristic parameters of damage for chosen conducting sola to the selected insulator. Experimental results show that thickness and electric conductivity of pollutant layer over insulators are the main parameters in damage evaluation. The flashover voltage decreases with increase of thickness and/or conductivity. These results provide a better basis on further revealing the damaging nature of conducting sol materials.
基金supported by the Natural Science Foundation of Hubei Province (2007ABA372)the New Century Excellent Talents in University (NCET-06-0676)
文摘Cr2O3 has eminent slag corrosion resistance. So, the magnesite -chrome brick is thought as an important refractory material used in RH refining furnace in the process of steel-making around the world. After chromebearing sols being prepared by sol-gel method, single sol （ Cr（ OH）3） and mixed sol （ Mg（ OH）2 - Cr（ OH）3） were impregnated into magnesite - chrome bricks by vacuum impregnation. The corrosion resistance of the impregnated bricks to silicon steel slag was studied by porosimetric analysis and fractal dimension calculation. The results showed that the corrosion resistance of impregnated magnesite -chrome brick was better than that of the unimpregnated brick and the brick impregnated by MgSO4 solution, and the one which has surface-treated by Mg（ OH）2 -Cr（OH）3 sol was the best, mainly because of lower apparent porosity, smaller pores diameter and their smoother inner sarface.
文摘The TiO2, MoO3, PEO doped four-member tungstic acid sols were prepared for the first time. The stability of different doped content sols were investigated and optimized with rotational viscometer. The four-member doped tungstic acid sol was very stable which could be stored more than two months at room temperature. The WO3 electrochromic film prepared from this doped four- member tungstic acid sol had excellent performance and longevity of service.
基金Supported by the Foundation for University Key Teacher of theMinistry of Education,the Key Research Project of the Ministry ofEducation (No.99087)
文摘Alumina sols with a molar ratio of 1 ： 50 between aluminum sec-batoxide（ ASB ） aud H2 O were fabricated by adding various amounts of nitric acid. The particle shape, zeta potential, polydispersity and effective particle size of alumina sol were examined by a TEM, a zeta PALS granularity analyzer and a zetaPALS zeta potential analyzer, respectively. By analyzing the change of zeta potential and doable-layer thickness with nitric acid concentration, the potential energy curves of colloidal particles were mapped on the basis of DLVO theory, and the effects of nitric acid concentration on the stability of alumina sols were intensively studied. The results show that for the alumina sols with a mol ratio of 1 ： 50 between ASB and H2O, the total interaction energy of the colloidal particle is at a maximum when the nitric acid concentration is 0.22 mol/ L. Therefore, the stability of the colloid reaches optimum at the nitric acid concentration of 0.22 mol / L.
基金Funded by Provincial Basic Research Projects(No.LJKMZ20220947)。
文摘The effects of liquid-solid ratio and reaction time on the leaching rate of magnesium at room temperature were investigated,as well as the effects of the molar ratio of MgO/MgCl_(2),the amount of water added,and the amount of acid-impregnated slag dosed on the compressive strength and water resistance of LR-MOC.The results showed that the magnesium element in the boron mud could be maximally leached under the conditions of 1:1 concentration of hydrochloric acid at room temperature,liquid-solid ratio of 2.5 mL·g^(-1),and reaction time of 5 h,and the main products were amorphous SiO_(2) as well as a small amount of magnesium olivine which had not been completely reacted.The LR-MOC prepared using the acid-soaked mixture could reach a softening coefficient of 0.85 for 28 d of water immersion when the molar ratio of MgO/MgCl_(2) was 2.2,the amount of water added was 0 g,and the acid-soaked slag dosing was 40 wt%,which also led to an appreciable late-strength,with an increase of 19.4%in compressive strength at 28 d compared to that at 7 d.Unlike previous studies,LR-MOC prepared in this way has a final strength phase that is not the more easily hydrolysed 3-phase but the lath-like 5-phase.For this phenomenon,we analyzed the mechanism and found that,during the acid leaching process,a part of amorphous SiO_(2) dissolved in the acid leaching solution formed a silica sol,in which Mg^(2+)played a bridging role to make the silica sol more stable.With the addition and hydrolysis of MgO,the silica sol gel coagulation slows down,providing a capping layer to inhibit the hydrolysis of the 5-phase crystals and providing some strength after coagulation.The amorphous SiO_(2) in the other part of the acid-impregnated slag generated M-S-H gel with Mg^(2+)and OH-,which synergised with the dense structure composed of interlocking crystals to improve the water resistance of LR-MOC.
基金supported by the Science and Technology Innovation Development Program(No.70304901).
文摘Cu_(2)ZnSnSSe_(4)(CZTSSe)thin film solar cells,with adjustable bandgap and rich elemental content,hold promise in next-gen photovoltaics.Crystalline quality is pivotal for efficient light absorption and carrier transport.During the post-selenization process,understanding crystal growth mechanisms,and improving layer quality are essential.We explored the effects of ramp rate and annealing temperature on CZTSSe films,using X-ray diffraction(XRD),Raman spectroscopy,scanning electron microscope(SEM),and ultraviolet-visual spectrophotometry(UV-Vis).The optimal performance occurred at 25.25°C/min ramp rate and 530°C annealing.This led to smoother surfaces,higher density,and larger grains.This condition produced a single-layer structure with large grains,no secondary phases,and a 1.14 eV bandgap,making it promising for photovoltaic applications.The study has highlighted the effect of selenization conditions on the characteristics of the CZTSSe absorber layer and has provided valuable information for developing CZTSSe thin film solar cells.
文摘The lining materials for blast furnaces have evolved from brick masonry to monolithic refractory materials.Monolithic castables are widely used in various industrial furnaces.The rapid development of silica sol materials,combined with the commonly used construction methods of casting and spraying,offers greater flexibility,efficiency,environmental friendliness,and a longer lifespan.Typical monolithic refractory technologies,such as the integral casting technique for the furnace hearth,the pre-applied slag coating technique for the furnace belly and waist,and the inner lining gunning technique,are grounded in scientific theory and practice,thereby advancing the development of refractory materials and enhancing the operational quality of blast furnaces.
基金Funded by the Natural Science Foundation of Hubei Province(No.2024AFB833)。
文摘Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resin composites.The influences of the SiB_(6)/SiO_(2)mixed modification on silica fiber properties were analyzed through thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and X-ray diffraction(XRD),respectively.Additionally,the influence of the SiB_(6)/SiO_(2)mixed modification on the mechanical properties of phenolic resin matrix composites was evaluated through mechanical testing.The experimeatal results indicate that the SiB_(6)/SiO_(2)mixed surface modification shows significant improvement in strength at room temperature and high temperatures,and crystallization temperature of silica fiber increases.The SiB_(6)/Silica sol co-modified silica fiber shows potential for future application in thermal protection and other high-temperature conditions.
基金financially supported by the Jiangsu Provincial Outstanding Overseas Talent Project,China(No.BX2023029)the Jiangsu Provincial Natural Science Fund Research Project,China(No.BK20211344)+2 种基金the Project of Jiangsu Provincial Department of Science and Technology,Chinathe Jiangsu Provincial Postgraduate Research&Practice Innovation Program,China(No.KYCX22_3795)the Jiangsu Provincial Postgraduate Research&Practice Innovation Program,China(No.SJCX23_2171)。
文摘This study successfully developed a series of carbon-sol-reinforced copper(Cu-CS)composite coatings by electrodeposition employing a superiorly dispersed carbon sol(CS)to avoid nanoparticle aggregation.The CS,characterized using transmission electron microscopy and zeta potential analysis,consisted of carbon particles with an approximate diameter of 300 nm uniformly distributed in the electrolytes.The characteristics of the composite coatings were examined via scanning electron microscopy to observe its microstructures,X-ray diffraction to detect its phase constituents,and durability testing to determine the wear and corrosion resistance.Results indicated a significant improvement in coating thickness,density,and uniformity achieved for the Cu-CS composite coating with the addition of 20m L/L CS.Moreover,the Cu-CS composite coating exhibited a low wear volume(1.15×10^(-3)mm^(3)),a high hardness(HV_(0.5)137.1),and a low corrosion rate(0.191 mm/a).The significant contribution of carbon particles to the improvement of coating performance is mainly influenced by two factors,namely,the strengthening and lubricating effects resulting from the incorporated carbon particles.Nevertheless,overdosage of CS can compromise the microstructure of the Cu-CS composite coating,creating defects and undermining its functionality.
文摘Founded in 2016,Zhejiang Haiyin Digital Technology Co.,Ltd.stands at the forefront of innovation as a certified China National High-Tech Enterprise,relentlessly advancing the boundaries of single-pass digital printing technology.Our crowning achievement—the revolutionary KUNR High-Speed Digital Printing System—earned China’s prestigious National First-in-Kind Certification.Engineered with 100%independent patents across mechanical,control,software,ink supply,and inks,we deliver tailored intelligent turnkey solutions that transform textile production dynamics.
基金the support from National Natural Science Foundation of China (No.52004179)the Fundamental Research Program of Shanxi Province,China (Nos.202403021211028,202303021211036)+1 种基金Shanxi Water and Wood New Carbon Materials Technology Co.,Ltd.,ChinaGuangdong One Nano Technology Co.,Ltd.,China。
文摘In order to restrain the huge volume expansion of bismuth(Bi)anodes in sodium ion batteries(SIBs),the core-shell structure Bi@mesoporous carbon nanospheres(Bi@mC)composite was designed and prepared by sol-gel method coupled heat treatment.Structural characterization displays that the average diameter of the as-prepared Bi@mC composites is about 200 nm and thickness of the N-doped mesoporous carbon shells is 20-30 nm.Electrochemical test and kinetic analysis results show that the mesoporous carbon shell can not only effectively relieve the stress caused by volume expansion of Bi and protect active material from pulverization caused by the stress during charging/discharging process,but also facilitate quick diffusion of sodium ions,thus improving rate and cycling performance.Bi@mC delivers a high specific capacity of 279 mA·h/g and a capacity retention of 97.6%after 3500 cycles at a current density of 5 A/g.Even at a high current density of 20 A/g,Bi@mC can still maintain a high specific capacity of 266 mA·h/g.Additionally,the Bi@mC//NVP full button sodium-ion batteries(SIBs)assembled using Bi@mC anode and Na_(3)V_(2)(PO_(4))_(3)(NVP)cathode deliver an energy density of 182 W·h/kg.
文摘Rare earth metals and transition metals co-substitution have been shown to tailor the physical properties of BiFeO_(3).In this work,a series of Bi_(1-x)RE_(x)Fe_(1-x)Zr_(x)O_(3)(RE=La,Pr,Nd,Sm;x=0.00,0.03,0.06)multiferroic ferrites was synthesized using the sol-gel method.To gain comprehensive insights into these materials,we employed a range of characterization techniques,including X-ray diffraction,Raman and Fourier transform infrared spectroscopies,field emission scanning electron microscopy,UV-Vis spectroscopy,and a vibrating sample magnetometer.Our analysis reveals a rhombohedral crystal structure(R3c space group)for the synthesized ferrites.Notably,we observe a substantial decrease in the optical band gap as the RE/Zr co-substitution increases.Further investigation into the magnetic properties shows a remarkable transition from antiferromagnetic to ferromagnetic behavior,which we attribute to the disruption of the long-range periodicity of the spin cycloid and 4f-3d orbital interactions.In addition,we tested the photocatalytic performance of the RE/Zr co-substituted BiFeO_(3)nanoparticles for the degradation of methyl orange dye under sunlight.The results are quite impressive,with degradation efficiency reaching up to 100%at 40 min by the Bi_(1-x)RE_(x)Fe_(1-x)Zr_(x)O_(3)(RE=La,Sm).Overall,our study demonstrates the vast potential of Bi_(1-x)RE_(x)Fe_(1-x)Zr_(x)O_(3)ferrites in various fields,including optics,magnetism,water treatment,and environmental preservation.
