In order to improve the corrosion resistance and microhardness of AZ91D magnesium alloy, TiN nanoparticles were addedto fabricate Ni-P-TiN composite coating by electrodeposition. The surface, cross-section morphology ...In order to improve the corrosion resistance and microhardness of AZ91D magnesium alloy, TiN nanoparticles were addedto fabricate Ni-P-TiN composite coating by electrodeposition. The surface, cross-section morphology and composition wereexamined using SEM, EDS and XRD, and the corrosion resistance was checked by electrochemical technology. The results indicatethat TiN nanoparticles were doped successfully in the Ni-P matrix after a series of complex pretreatments including activation, zincimmersion and pre-electroplating, which enhances the stability of magnesium alloy in electrolyte and the adhesion betweenmagnesium alloy and composite coating. The microhardness of the Ni-P coating increases dramatically by adding TiN nanoparticlesand subsequent heat treatment. The corrosion experimental results indicate that the corrosion resistance of Ni-P-TiN compositecoating is much higher than that of uncoated AZ91D magnesium alloy and similar with Ni-P coating in short immersion time.However, TiN nanoparticles play a significant role in long-term corrosion resistance of composite coatings.展开更多
Photocatalytic degradation of phenol with sol-gel prepared rare earth doped tin dioxide (SnO2) nanoparticles was reported. Gadolinium doped tin dioxide (SnO2:Gd) nanoparticles were found to absorb higher visible ...Photocatalytic degradation of phenol with sol-gel prepared rare earth doped tin dioxide (SnO2) nanoparticles was reported. Gadolinium doped tin dioxide (SnO2:Gd) nanoparticles were found to absorb higher visible light compared to lanthanum, neodymium and cerium doped materials that were studied in detail. Photocatalytic degradation of phenol under artificial white light and sunlight in the presence of SnO2:Gd nanoparticles was studied with high performance liquid chromatography (HPLC), capillary electrophoresis (CE), total organic carbon (TOC) measurements and the determination of chemical oxygen demand (COD). Clear correlations be- tween the results obtained from these multiple measurements were found, and a kinetic pathway for the degradation process was pro- posed. Within 150 min of solar irradiation, the TOC of a 10 ppm phenol solution in water was reduced by 95%-99%, thus demon- strating that SnO2:Gd nanoparticles are efficient visible light photocatalysts.展开更多
Lithium-sulfur(Li-S)batteries have attracted significant attention for their high specific capacity,non-toxic and harmless advantages.However,the shuttle effect limits their development.In this work,small-sized tin di...Lithium-sulfur(Li-S)batteries have attracted significant attention for their high specific capacity,non-toxic and harmless advantages.However,the shuttle effect limits their development.In this work,small-sized tin disulfide(SnS_(2))nanoparticles are embedded between interlayers of twodimensional porous carbon nanosheets(PCNs),forming a multi-functional nanocomposite(PCN-SnS_(2))as a cathode carrier for Li-S batteries.The graphitized carbon nanosheets improve the overall conductivity of the electrode,and the abundant pores not only facilitate ion transfer and electrolyte permeation,but also buffer the volume change during the charge and discharge process to ensure the integrity of the electrode material.More importantly,the physical confinement of PCN,as well as the strong chemical adsorption and catalytic reaction of small SnS_(2)nanoparticles,synergistically reduce the shuttle effect of polysulfides.The interaction between a porous layered structure and physical-chemical confinement gives the PCN-SnS_(2)-S electrode high electrochemical performance.Even at a high rate of 2 C,a discharge capacity of 650 mA h g^(-1)is maintained after 150 cycles,underscoring the positive results of SnS_(2)-based materials for Li-S batteries.The galvanostatic intermittent titration technique results further confirm that the PCN-SnS_(2)-S electrode has a high Li+transmission rate,which reduces the activation barrier and improves the electrochemical reaction kinetics.This work provides strong evidence that reducing the size of SnS_(2)nanostructures is beneficial for capturing and reacting with polysulfides to alleviate their shuttle effect in Li-S batteries.展开更多
The effect of particle size on the density and resistivity of ITO green bodies and targets was systematically investigated.The experimental results show that the relative density of ITO green bodies decreases with the...The effect of particle size on the density and resistivity of ITO green bodies and targets was systematically investigated.The experimental results show that the relative density of ITO green bodies decreases with the increase of ITO particle size.When the particle size is 10.7 nm,the relative density of ITO green bodies rises to the maximum value of 56.6%.The resistivity declines exponentially with the increase of particle size,which satisfies the exponential equation of R=exp(-41.823 × d).When the particle size is 41.6 nm,the resistivity reaches the minimum value of 0.8 Ω·cm.The relative density of ITO target decreases with the increase of particle size.Fine particles can increase the driving force of densification in initial stage.Electron mobility,caused by grain boundary scattering,will increase due to the increase of particle size or the decrease of grain boundary potential.When the particle size is 10.7 nm,the target with compact grain stacking and low porosity shows a maximum relative density of 99.25%,and the resistivity reaches the minimum value of 0.34×10^-3 Ω·cm.展开更多
The use of solar energy to produce steam is an effective method to purify sewage or seawater. Herein, we deposited TiN nanoparticles(NPs) on a piece of carbonized wood as a new type of double layer material for solar ...The use of solar energy to produce steam is an effective method to purify sewage or seawater. Herein, we deposited TiN nanoparticles(NPs) on a piece of carbonized wood as a new type of double layer material for solar water evaporation. TiN NPs possess better stability, lower cost,lower toxicity and wider and stronger optical absorption than the previously reported photo-thermal conversion(PTC)materials, such as plasmonic metals, carbon-based materials and semiconductor nanomaterials. The amounts of TiN NPs and the thicknesses and types of the substrates have important influences on water evaporation rates and solar-vapor conversion efficiency. A solar-vapor conversion efficiency of 92.5%, the highest efficiency in the reported wood-based PTC materials, is obtained under 1-sun simulated solar irradiation.In addition, the TBCF hybrid materials(TiN NPs on biocarbon foam) exhibit good reusability.展开更多
Rational designing and controlling of nanostructures is a key factor in realizing appropriate properties required for the high-performance energy fields. In the present study, hollow Sn O2@C nanoparticles(NPs) with ...Rational designing and controlling of nanostructures is a key factor in realizing appropriate properties required for the high-performance energy fields. In the present study, hollow Sn O2@C nanoparticles(NPs) with a mean size of 50 nm have been synthesized in large-scale via a facile hydrothermal approach.The morphology and composition of as-obtained products were studied by various characterized techniques. As an anode material for lithium ion batteries(LIBs), the as-prepared hollow Sn O2@C NPs exhibit significant improvement in cycle performances. The discharge capacity of lithium battery is as high as 370 m Ah g 1, and the current density is 3910 m A g 1(5 C) after 573 cycles. Furthermore, the capacity recovers up to 1100 m Ah g 1at the rate performances in which the current density is recovered to 156.4 m A g 1(0.2 C). Undoubtedly, sub-100 nm Sn O2@C NPs provide significant improvement to the electrochemical performance of LIBs as superior-anode nanomaterials, and this carbon coating strategy can pave the way for developing high-performance LIBs.展开更多
基金Projects(51171172,51131005)supported by the National Natural Science Foundation of ChinaProject(R16E010001)supported by Zhejiang Provincial Natural Science Foundation of China+1 种基金Project(2015QNA3011)supported by Fundamental Research Funds for the Central Universities,ChinaProject(14DZ2261000)supported by Science and Technology Commission of Shanghai Municipality,China
文摘In order to improve the corrosion resistance and microhardness of AZ91D magnesium alloy, TiN nanoparticles were addedto fabricate Ni-P-TiN composite coating by electrodeposition. The surface, cross-section morphology and composition wereexamined using SEM, EDS and XRD, and the corrosion resistance was checked by electrochemical technology. The results indicatethat TiN nanoparticles were doped successfully in the Ni-P matrix after a series of complex pretreatments including activation, zincimmersion and pre-electroplating, which enhances the stability of magnesium alloy in electrolyte and the adhesion betweenmagnesium alloy and composite coating. The microhardness of the Ni-P coating increases dramatically by adding TiN nanoparticlesand subsequent heat treatment. The corrosion experimental results indicate that the corrosion resistance of Ni-P-TiN compositecoating is much higher than that of uncoated AZ91D magnesium alloy and similar with Ni-P coating in short immersion time.However, TiN nanoparticles play a significant role in long-term corrosion resistance of composite coatings.
基金partial financial support from the Chair in Nanotechnology Programme of the Research Council of Oman
文摘Photocatalytic degradation of phenol with sol-gel prepared rare earth doped tin dioxide (SnO2) nanoparticles was reported. Gadolinium doped tin dioxide (SnO2:Gd) nanoparticles were found to absorb higher visible light compared to lanthanum, neodymium and cerium doped materials that were studied in detail. Photocatalytic degradation of phenol under artificial white light and sunlight in the presence of SnO2:Gd nanoparticles was studied with high performance liquid chromatography (HPLC), capillary electrophoresis (CE), total organic carbon (TOC) measurements and the determination of chemical oxygen demand (COD). Clear correlations be- tween the results obtained from these multiple measurements were found, and a kinetic pathway for the degradation process was pro- posed. Within 150 min of solar irradiation, the TOC of a 10 ppm phenol solution in water was reduced by 95%-99%, thus demon- strating that SnO2:Gd nanoparticles are efficient visible light photocatalysts.
基金the National Key R&D Program of China(2016YFA0202602)the National Natural Science Foundation of China(U1663225)+3 种基金the Fundamental Research Funds for the Central Universities(2020-YB-009)the Academy of Scientific Research and Technology(6611,ASRT,Egypt)the 111 National project(B20002)from the Ministry of Science and Technology and the Ministry of Education,ChinaSinopec Ministry of Science and Technology Basic Prospective Research Project(217027-5 and 218025-9)。
文摘Lithium-sulfur(Li-S)batteries have attracted significant attention for their high specific capacity,non-toxic and harmless advantages.However,the shuttle effect limits their development.In this work,small-sized tin disulfide(SnS_(2))nanoparticles are embedded between interlayers of twodimensional porous carbon nanosheets(PCNs),forming a multi-functional nanocomposite(PCN-SnS_(2))as a cathode carrier for Li-S batteries.The graphitized carbon nanosheets improve the overall conductivity of the electrode,and the abundant pores not only facilitate ion transfer and electrolyte permeation,but also buffer the volume change during the charge and discharge process to ensure the integrity of the electrode material.More importantly,the physical confinement of PCN,as well as the strong chemical adsorption and catalytic reaction of small SnS_(2)nanoparticles,synergistically reduce the shuttle effect of polysulfides.The interaction between a porous layered structure and physical-chemical confinement gives the PCN-SnS_(2)-S electrode high electrochemical performance.Even at a high rate of 2 C,a discharge capacity of 650 mA h g^(-1)is maintained after 150 cycles,underscoring the positive results of SnS_(2)-based materials for Li-S batteries.The galvanostatic intermittent titration technique results further confirm that the PCN-SnS_(2)-S electrode has a high Li+transmission rate,which reduces the activation barrier and improves the electrochemical reaction kinetics.This work provides strong evidence that reducing the size of SnS_(2)nanostructures is beneficial for capturing and reacting with polysulfides to alleviate their shuttle effect in Li-S batteries.
基金Funded by the Beijing Municipal Natural Science Foundation (No. 2192041)。
文摘The effect of particle size on the density and resistivity of ITO green bodies and targets was systematically investigated.The experimental results show that the relative density of ITO green bodies decreases with the increase of ITO particle size.When the particle size is 10.7 nm,the relative density of ITO green bodies rises to the maximum value of 56.6%.The resistivity declines exponentially with the increase of particle size,which satisfies the exponential equation of R=exp(-41.823 × d).When the particle size is 41.6 nm,the resistivity reaches the minimum value of 0.8 Ω·cm.The relative density of ITO target decreases with the increase of particle size.Fine particles can increase the driving force of densification in initial stage.Electron mobility,caused by grain boundary scattering,will increase due to the increase of particle size or the decrease of grain boundary potential.When the particle size is 10.7 nm,the target with compact grain stacking and low porosity shows a maximum relative density of 99.25%,and the resistivity reaches the minimum value of 0.34×10^-3 Ω·cm.
文摘The use of solar energy to produce steam is an effective method to purify sewage or seawater. Herein, we deposited TiN nanoparticles(NPs) on a piece of carbonized wood as a new type of double layer material for solar water evaporation. TiN NPs possess better stability, lower cost,lower toxicity and wider and stronger optical absorption than the previously reported photo-thermal conversion(PTC)materials, such as plasmonic metals, carbon-based materials and semiconductor nanomaterials. The amounts of TiN NPs and the thicknesses and types of the substrates have important influences on water evaporation rates and solar-vapor conversion efficiency. A solar-vapor conversion efficiency of 92.5%, the highest efficiency in the reported wood-based PTC materials, is obtained under 1-sun simulated solar irradiation.In addition, the TBCF hybrid materials(TiN NPs on biocarbon foam) exhibit good reusability.
基金the Program for the NSFC (Nos. 51302325, 51201115, 51471121)New Century Excellent Talents in University (No. NCET-12-0553)+4 种基金Program for Shenghua Overseas Talent (No. 1681-7607030005) from Central South UniversityHubei Provincial Natural Science Foundation (No. 2014CFB261)the partial financial support from the Open-End Fund for the Valuable and Precision Instruments of Central South University (No. CSUZC2014032)Fundamental Research Funds for the Central Universities (No. 2042015kf0184)Wuhan University
文摘Rational designing and controlling of nanostructures is a key factor in realizing appropriate properties required for the high-performance energy fields. In the present study, hollow Sn O2@C nanoparticles(NPs) with a mean size of 50 nm have been synthesized in large-scale via a facile hydrothermal approach.The morphology and composition of as-obtained products were studied by various characterized techniques. As an anode material for lithium ion batteries(LIBs), the as-prepared hollow Sn O2@C NPs exhibit significant improvement in cycle performances. The discharge capacity of lithium battery is as high as 370 m Ah g 1, and the current density is 3910 m A g 1(5 C) after 573 cycles. Furthermore, the capacity recovers up to 1100 m Ah g 1at the rate performances in which the current density is recovered to 156.4 m A g 1(0.2 C). Undoubtedly, sub-100 nm Sn O2@C NPs provide significant improvement to the electrochemical performance of LIBs as superior-anode nanomaterials, and this carbon coating strategy can pave the way for developing high-performance LIBs.