The structural un-uniformity of microcrystalline silicon, thin film, amorphous incubation layerc-Si：H films prepared using very high frequency plasma-enhanced chemical vapour deposition method has been investigated ...The structural un-uniformity of microcrystalline silicon, thin film, amorphous incubation layerc-Si：H films prepared using very high frequency plasma-enhanced chemical vapour deposition method has been investigated by Raman spectroscopy, spectroscopic ellipsometer and atomic force mi- croscopy. It was found that the formation of amorphous incubation layer was caused by the back diffusion of SiH4 and the amorphous induction of glass surface during the initial ignition process, and growth of the incubation layer can be suppressed and uniform μc-Si：H phase is generated by the application of delayed initial SiH4 density and silane profiling methods.展开更多
Amorphous-layer-free nanocrystalline silicon films were prepared by a very high frequency plasma enhanced chem-ical vapor deposition （PECVD） technique using hydrogen-diluted Sill4 at 250 ℃. The dependence of the cr...Amorphous-layer-free nanocrystalline silicon films were prepared by a very high frequency plasma enhanced chem-ical vapor deposition （PECVD） technique using hydrogen-diluted Sill4 at 250 ℃. The dependence of the crystallinity of the film on the hydrogen dilution ratio and the film thickness was investigated. Raman spectra show that the thickness of the initial amorphous incubation layer on silicon oxide gradually decreases with increasing hydrogen dilution ratio. High-resolution transmission electron microscopy reveals that the initial amorphous incubation layer can be completely eliminated at a hydrogen dilution ratio of 98%, which is lower than that needed for the growth of amorphous-layer-free nanocrystalline silicon using an excitation frequency of 13.56 MHz. More studies on the microstructure evolution of the initial amorphous incubation layer with hydrogen dilution ratios were performed using Fourier-transform infrared spectroscopy. It is suggested that the high hydrogen dilution, as well as the higher plasma excitation frequency, plays an important role in the formation of amorphous-layer-free nanocrystalline silicon films.展开更多
Large-scale components of steel and aluminum alloys(Fe-Al)with high bonding strength are highly needed from space exploration to the fabrication of transportation systems.The formation of detrimental intermetallic com...Large-scale components of steel and aluminum alloys(Fe-Al)with high bonding strength are highly needed from space exploration to the fabrication of transportation systems.The formation of detrimental intermetallic compounds at the Al-Fe interface has limited the application range of the Fe-Al components.The modified friction stir additive manufacturing was developed for fabricating large-scale Fe-Al compo-nents with homogenously distributed interfacial amorphous layers rather than detrimental intermetallic compounds.The interfacial amorphous layers comprised an Mg-O rich amorphous layer<20 nm in thick-ness and an Al-Fe-Si amorphous layer<120 nm in thickness.The interfacial amorphous layers exhibited high thermal stability and did not change even after the post-processing heat treatment of heating at 500℃ for 20 min and aging at 170℃ for 7 h.The tensile strengths of the Fe-Al tensile specimens were increased from 160 to 250 MPa after the application of the post-processing heat treatment.The fracture occurred in the aluminum alloys instead of at the dissimilar metal interface,demonstrating that high bonding strength at the Al-Fe interface was enabled by the formation of homogenously distributed interfacial amorphous layers.展开更多
Electrocatalytic converting CO_(2) into chemical products has emerged as a promising approach to achieving carbon neutrality.Herein,we report a bismuth-based catalyst with high curvature terminal and amorphous layer w...Electrocatalytic converting CO_(2) into chemical products has emerged as a promising approach to achieving carbon neutrality.Herein,we report a bismuth-based catalyst with high curvature terminal and amorphous layer which fabricated via two-step electrodeposition achieves stable formate output in a wide voltage window of 600 mV.The Faraday efficiency(FE) of formate reached up to 99.4% at-0.8 V vs.RHE and it remained constant for more than 92 h at-15 mA cm^(-2).More intriguingly,FE formate of95.4% can be realized at a current density of industrial grade(-667.7 mA cm^(-2)) in flow cell.The special structure promoted CO_(2) adsorption and reduced its activation energy and enhanced the electric-thermal field and K^(+) enrichment which accelerated the reaction kinetics.In situ spectroscopy and theoretical calculation further confirmed that the introduction of amorphous structure is beneficial to adsorpting CO_(2)and stabling*OCHO intermediate.This work provides special insights to fabricate efficient electrocatalysts by means of structural and crystal engineering and makes efforts to realize the industrialization of bismuth-based catalysts.展开更多
To improve the thermal stability of nanocrystalline(NC)metals,their interface structure can be modified by applying amorphous intergranular layers.However,traditional amorphous metallic intergranular layers are rarely...To improve the thermal stability of nanocrystalline(NC)metals,their interface structure can be modified by applying amorphous intergranular layers.However,traditional amorphous metallic intergranular layers are rarely formed in most pure metals or alloys.In this study,we demonstrate that amorphous oxide intergranular layers can greatly improve the thermal stability of NC metals by tailoring the grain boundaries(GBs)of NC metals.Using a Au-ZrO_(2) model system,ultra-fine Au nanoparticles(∼3 nm)with exceptional thermal stability at temperatures up to 600℃ were formed after introducing amorphous ZrO_(2) intergranular layers at the GBs of NC Au.Quantitative thermodynamic model calculations revealed that the exceptional thermal stability of the Au nanoparticles originated fundamentally from the formation of low-energy Au|ZrO_(2) interfaces.The kinetic stabilization was further discussed,showing that the Ostwald ripening of Au nanoparticles was suppressed due to the presence of amorphous ZrO_(2) intergranular.This study sheds light on new strategies for enhancing the thermal stability of NC metals by utilizing amorphous oxide intergranular layers,paving the way for the achievement of ultra-stable NC metals through interface modification.展开更多
Lithium-and manganese-rich(LMR)oxide cathode materials are among the most attractive candidates for next-generation energy-storage materials owing to their anomalous capacity.However,severe Mn dissolution that occurs ...Lithium-and manganese-rich(LMR)oxide cathode materials are among the most attractive candidates for next-generation energy-storage materials owing to their anomalous capacity.However,severe Mn dissolution that occurs during long-term cycling,which leads to capacity loss,hinders their application prospects.In this study,nanoscale AlPO_(4)-coated Li_(1.2)Ni_(0.13)Co_(0.13)Mn_(0.54)O_(2)(LMR@APO)with significantly enhanced electrochemical performance is successfully synthesized using a simple and effective sol–gel method to mitigate Mn dissolution and suppress local structural distortion at high voltages.Because of the complex evolution of the structure and oxidation state of LMR materials during electrochemical cycling,observing and analyzing them using traditional single characterization methods may be difficult.Therefore,we combine various synchrotron-based characterization techniques to conduct a detailed analysis of the electronic and coordination structures of the cathode material from the surface to the bulk.Synchrotron-based hard and soft X-ray spectroscopies are integrated to investigate the differences in O and Mn evolution between the surfaces and bulk of the cathode.Advanced synchrotron-based transmission X-ray microscopy combined with X-ray near-edge absorption-structure technology is utilized to visualize the two-dimensional nanometer-scale reactivity of the LMR cathode.The AlPO_(4)-coating layer can stabilize the surface structure of the LMR material,effectively alleviating irreversible oxygen release on the surface and preventing the dissolution of Mn^(2+)at the interface caused by side reactions after a long cycle.Therefore,the spatial reaction uniformity of Mn is enhanced by the AlPO_(4)-coating layer,and rapid capacity decay caused by Mn deactivation is prevented.The AlPO_(4)-coating method is a facile modification strategy for high-performance LMR materials.展开更多
Flexible aqueous energy storage devices with high security and flexibility are crucial for the progress of wearable energy storage.Particularly,aqueous rechargeable Ni-Fe batteries owning a large theoretical capacity,...Flexible aqueous energy storage devices with high security and flexibility are crucial for the progress of wearable energy storage.Particularly,aqueous rechargeable Ni-Fe batteries owning a large theoretical capacity,low cost and outstanding safety characteristics have emerged as a promising candidate for flexible aqueous energy storage devices.Herein,Cu-doped Fe_(3)O_(4)(CFO)with 3D coral structure was prepared by doping Cu^(2+) based on Fe_(3)O_(4)nanosheets(FO).Furthermore,the Fe-based anode material(CFPO)grown on carbon fibers was obtained by reconstructing the surface of CFO to form a low-crystallization shell which can enhance the ion transport.Excitingly,the newly developed CFPO electrode as an innovative anode material further exhibited a high capacity of 117.5 mAh g^(-1)(or 423 F g^(-1))at 1 A g^(-1).Then,the assembled aqueous Ni-Fe batteries with a high cell-voltage output of 1.6 V deliver a high capacity of 49.02 mAh g^(-1) at 1 A g^(-1) and retention ratio of 96.8%for capacitance after 10000 continuous cycles.What’s more,the aqueous quasi-solid-state batteries present a remarkable maximal energy density of 45.6 Wh kg^(-1) and a power density of 12 kW kg^(-1).This work provides an innovative and feasible way and optimization idea for the design of high-performance Fe-based anodes,and may promote the development of a new generation of flexible aqueous Ni-Fe batteries.展开更多
This study is designed to determine whether the outermost layer of articular cartilage is deficient in Osteoarthritis (OA). Phospholipids present in healthy and osteoarthritis (OA) synovial fluid show significant diff...This study is designed to determine whether the outermost layer of articular cartilage is deficient in Osteoarthritis (OA). Phospholipids present in healthy and osteoarthritis (OA) synovial fluid show significant differences in their concentration. While examining the surface properties of OA joints, we found that OA PLs molecules cannot support lubrication, and increased friction was observed. Our lubrication mechanism was based on a surface active phospholipids (SAPL) multibilayer which in OA condition was deactivated and removed from the cartilage surface under OA conditions. Cartilage wettability study clearly demonstrated a significant decrease in hydrophobicity, the contact angle, θ (theta), dropping from 103° from bovine healthy cartilage to 65° in surface partially depleted and 35.1° for completely depleted surface. These results are discussed in the context that surface active phospholipid (SAPL) and lubricin, each has specific roles in a lamellar-repulsive lubrication system. However, deactivated phospholipid molecules are major indicator of cartilage wear (model) introduced in this study.展开更多
基金Project supported by the State Key Development Program for Basic Research of China(Grant No.2006CB202601)the Natural Science Research Program of the Education Bureau of Henan Province of China(Grant No.2009A140007)
文摘The structural un-uniformity of microcrystalline silicon, thin film, amorphous incubation layerc-Si：H films prepared using very high frequency plasma-enhanced chemical vapour deposition method has been investigated by Raman spectroscopy, spectroscopic ellipsometer and atomic force mi- croscopy. It was found that the formation of amorphous incubation layer was caused by the back diffusion of SiH4 and the amorphous induction of glass surface during the initial ignition process, and growth of the incubation layer can be suppressed and uniform μc-Si：H phase is generated by the application of delayed initial SiH4 density and silane profiling methods.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60806046)the Natural Science Foundation of Guangdong Province of China (Grant No. S2011010001853)the FDYT (Grant No. LYM10099)
文摘Amorphous-layer-free nanocrystalline silicon films were prepared by a very high frequency plasma enhanced chem-ical vapor deposition （PECVD） technique using hydrogen-diluted Sill4 at 250 ℃. The dependence of the crystallinity of the film on the hydrogen dilution ratio and the film thickness was investigated. Raman spectra show that the thickness of the initial amorphous incubation layer on silicon oxide gradually decreases with increasing hydrogen dilution ratio. High-resolution transmission electron microscopy reveals that the initial amorphous incubation layer can be completely eliminated at a hydrogen dilution ratio of 98%, which is lower than that needed for the growth of amorphous-layer-free nanocrystalline silicon using an excitation frequency of 13.56 MHz. More studies on the microstructure evolution of the initial amorphous incubation layer with hydrogen dilution ratios were performed using Fourier-transform infrared spectroscopy. It is suggested that the high hydrogen dilution, as well as the higher plasma excitation frequency, plays an important role in the formation of amorphous-layer-free nanocrystalline silicon films.
基金supported by the National Natu-ral Science Foundation of China(Nos.52375396,52034005,and 51975553)the Liaoning Provincial Department of Science and Technology(No.2023JH2/101300149)+4 种基金the Shenyang Science and Technology Bureau(No.22-315-6-03)and Institute of Metal Re-search,Chinese Academy of Sciences(No.2023-ZD02-01)the Liaoning Province Excellent Youth Foundation(No.2021-YQ-01)the Program of the Youth Innovation Promotion Association of the Chi-nese Academy of Sciences(No.Y2021061)the Bintech-IMR R&D Program(No.GYY-JSBU-2022-002).
文摘Large-scale components of steel and aluminum alloys(Fe-Al)with high bonding strength are highly needed from space exploration to the fabrication of transportation systems.The formation of detrimental intermetallic compounds at the Al-Fe interface has limited the application range of the Fe-Al components.The modified friction stir additive manufacturing was developed for fabricating large-scale Fe-Al compo-nents with homogenously distributed interfacial amorphous layers rather than detrimental intermetallic compounds.The interfacial amorphous layers comprised an Mg-O rich amorphous layer<20 nm in thick-ness and an Al-Fe-Si amorphous layer<120 nm in thickness.The interfacial amorphous layers exhibited high thermal stability and did not change even after the post-processing heat treatment of heating at 500℃ for 20 min and aging at 170℃ for 7 h.The tensile strengths of the Fe-Al tensile specimens were increased from 160 to 250 MPa after the application of the post-processing heat treatment.The fracture occurred in the aluminum alloys instead of at the dissimilar metal interface,demonstrating that high bonding strength at the Al-Fe interface was enabled by the formation of homogenously distributed interfacial amorphous layers.
基金financial support from the Zhejiang Provincial Natural Science Foundation of China(LQ22B060007)the National Natural Science Foundation of China(22206042)+2 种基金the Scientific Research Start-up of Hangzhou Normal University(2021GDL014)the Hebei Natural Science Foundation(E2021203047)the Hebei Provincial Foundation for Returness(C20200369)。
文摘Electrocatalytic converting CO_(2) into chemical products has emerged as a promising approach to achieving carbon neutrality.Herein,we report a bismuth-based catalyst with high curvature terminal and amorphous layer which fabricated via two-step electrodeposition achieves stable formate output in a wide voltage window of 600 mV.The Faraday efficiency(FE) of formate reached up to 99.4% at-0.8 V vs.RHE and it remained constant for more than 92 h at-15 mA cm^(-2).More intriguingly,FE formate of95.4% can be realized at a current density of industrial grade(-667.7 mA cm^(-2)) in flow cell.The special structure promoted CO_(2) adsorption and reduced its activation energy and enhanced the electric-thermal field and K^(+) enrichment which accelerated the reaction kinetics.In situ spectroscopy and theoretical calculation further confirmed that the introduction of amorphous structure is beneficial to adsorpting CO_(2)and stabling*OCHO intermediate.This work provides special insights to fabricate efficient electrocatalysts by means of structural and crystal engineering and makes efforts to realize the industrialization of bismuth-based catalysts.
基金financially supported by the National Natural Science Foundation of China(No.51971153).
文摘To improve the thermal stability of nanocrystalline(NC)metals,their interface structure can be modified by applying amorphous intergranular layers.However,traditional amorphous metallic intergranular layers are rarely formed in most pure metals or alloys.In this study,we demonstrate that amorphous oxide intergranular layers can greatly improve the thermal stability of NC metals by tailoring the grain boundaries(GBs)of NC metals.Using a Au-ZrO_(2) model system,ultra-fine Au nanoparticles(∼3 nm)with exceptional thermal stability at temperatures up to 600℃ were formed after introducing amorphous ZrO_(2) intergranular layers at the GBs of NC Au.Quantitative thermodynamic model calculations revealed that the exceptional thermal stability of the Au nanoparticles originated fundamentally from the formation of low-energy Au|ZrO_(2) interfaces.The kinetic stabilization was further discussed,showing that the Ostwald ripening of Au nanoparticles was suppressed due to the presence of amorphous ZrO_(2) intergranular.This study sheds light on new strategies for enhancing the thermal stability of NC metals by utilizing amorphous oxide intergranular layers,paving the way for the achievement of ultra-stable NC metals through interface modification.
基金supported by the National Key R&D Program of China(No.2022YFB3807700)National Natural Science Foundation of China(Nos.U20A20248 and 52372247)+1 种基金Shanghai Pujiang Programme(23PJD110)Science and Technology Commission of Shanghai Municipality(No.18DZ2280800)。
文摘Lithium-and manganese-rich(LMR)oxide cathode materials are among the most attractive candidates for next-generation energy-storage materials owing to their anomalous capacity.However,severe Mn dissolution that occurs during long-term cycling,which leads to capacity loss,hinders their application prospects.In this study,nanoscale AlPO_(4)-coated Li_(1.2)Ni_(0.13)Co_(0.13)Mn_(0.54)O_(2)(LMR@APO)with significantly enhanced electrochemical performance is successfully synthesized using a simple and effective sol–gel method to mitigate Mn dissolution and suppress local structural distortion at high voltages.Because of the complex evolution of the structure and oxidation state of LMR materials during electrochemical cycling,observing and analyzing them using traditional single characterization methods may be difficult.Therefore,we combine various synchrotron-based characterization techniques to conduct a detailed analysis of the electronic and coordination structures of the cathode material from the surface to the bulk.Synchrotron-based hard and soft X-ray spectroscopies are integrated to investigate the differences in O and Mn evolution between the surfaces and bulk of the cathode.Advanced synchrotron-based transmission X-ray microscopy combined with X-ray near-edge absorption-structure technology is utilized to visualize the two-dimensional nanometer-scale reactivity of the LMR cathode.The AlPO_(4)-coating layer can stabilize the surface structure of the LMR material,effectively alleviating irreversible oxygen release on the surface and preventing the dissolution of Mn^(2+)at the interface caused by side reactions after a long cycle.Therefore,the spatial reaction uniformity of Mn is enhanced by the AlPO_(4)-coating layer,and rapid capacity decay caused by Mn deactivation is prevented.The AlPO_(4)-coating method is a facile modification strategy for high-performance LMR materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.51802177)Independent Cultivation Program of Innovation Team of Ji’nan City(Grant No.2019GXRC011)。
文摘Flexible aqueous energy storage devices with high security and flexibility are crucial for the progress of wearable energy storage.Particularly,aqueous rechargeable Ni-Fe batteries owning a large theoretical capacity,low cost and outstanding safety characteristics have emerged as a promising candidate for flexible aqueous energy storage devices.Herein,Cu-doped Fe_(3)O_(4)(CFO)with 3D coral structure was prepared by doping Cu^(2+) based on Fe_(3)O_(4)nanosheets(FO).Furthermore,the Fe-based anode material(CFPO)grown on carbon fibers was obtained by reconstructing the surface of CFO to form a low-crystallization shell which can enhance the ion transport.Excitingly,the newly developed CFPO electrode as an innovative anode material further exhibited a high capacity of 117.5 mAh g^(-1)(or 423 F g^(-1))at 1 A g^(-1).Then,the assembled aqueous Ni-Fe batteries with a high cell-voltage output of 1.6 V deliver a high capacity of 49.02 mAh g^(-1) at 1 A g^(-1) and retention ratio of 96.8%for capacitance after 10000 continuous cycles.What’s more,the aqueous quasi-solid-state batteries present a remarkable maximal energy density of 45.6 Wh kg^(-1) and a power density of 12 kW kg^(-1).This work provides an innovative and feasible way and optimization idea for the design of high-performance Fe-based anodes,and may promote the development of a new generation of flexible aqueous Ni-Fe batteries.
文摘This study is designed to determine whether the outermost layer of articular cartilage is deficient in Osteoarthritis (OA). Phospholipids present in healthy and osteoarthritis (OA) synovial fluid show significant differences in their concentration. While examining the surface properties of OA joints, we found that OA PLs molecules cannot support lubrication, and increased friction was observed. Our lubrication mechanism was based on a surface active phospholipids (SAPL) multibilayer which in OA condition was deactivated and removed from the cartilage surface under OA conditions. Cartilage wettability study clearly demonstrated a significant decrease in hydrophobicity, the contact angle, θ (theta), dropping from 103° from bovine healthy cartilage to 65° in surface partially depleted and 35.1° for completely depleted surface. These results are discussed in the context that surface active phospholipid (SAPL) and lubricin, each has specific roles in a lamellar-repulsive lubrication system. However, deactivated phospholipid molecules are major indicator of cartilage wear (model) introduced in this study.
