Metal-air battery is an environmental friendly energy storage system with unique open structure.Magnesium(Mg)and its alloys have been extensively attempted as anodes for air batteries due to high theoretical energy de...Metal-air battery is an environmental friendly energy storage system with unique open structure.Magnesium(Mg)and its alloys have been extensively attempted as anodes for air batteries due to high theoretical energy density,low cost,and recyclability.However,the study on Mg-air battery(MAB)is still at the laboratory level currently,mainly owing to the low anodic efficiency caused by the poor corrosion resistance.In order to reduce corrosion losses and achieve optimal utilization efficiency of Mg anode,the design strategies are reviewed from microstructure perspectives.Firstly,the corrosion behaviors have been discussed,especially the negative difference effect derived by hydrogen evolution.Special attention is given to the effect of anode micro-structures on the MAB,which includes grain size,grain orientation,second phases,crystal structure,twins,and dislocations.For further improvement,the discharge performance,long period stacking ordered phase and its enhancing effect are considered.Meanwhile,given the current debates over Mg dendrites,the potential risk,the impact on discharge,and the elimination strategies are discussed.Microstructure control and single crystal would be promising ways for MAB anode.展开更多
We report the Lewis acid catalysis of aryldiazonium salts,and their Lewis acidity applications in photogeneration of aryl radicals under additive-,photocatalyst-and transition metal-free conditions.In this visible lig...We report the Lewis acid catalysis of aryldiazonium salts,and their Lewis acidity applications in photogeneration of aryl radicals under additive-,photocatalyst-and transition metal-free conditions.In this visible light-mediated transformation,the Lewis acidic character of aryldiazonium salts enables access to the photoactive charge transfer complex with dichalcogenides.The usefulness and versatility of this new protocol are demonstrated through the chalcogenation of a variety of aryldiazonium salts.展开更多
The vacuum electromagnetic induction nitriding technology was applied to prepare a gradient nitrided layer on the surface of a Ti6Al4V alloy,which possesses TiN andα-Ti(N)phases.Moreover,transmission electron microsc...The vacuum electromagnetic induction nitriding technology was applied to prepare a gradient nitrided layer on the surface of a Ti6Al4V alloy,which possesses TiN andα-Ti(N)phases.Moreover,transmission electron microscopy was conducted to confirm the presence of numerous high-density stacking faults caused by TiN and Ti_(2)N phases distributed on the surface of the alloy,along with a large number of basal stacking faults inside.A highdensity stacking fault led to serious distortion of lattice fringes.Lattice and numerous edge dislocations caused by defects were observed in the subsurface layer.For the surface layer,the Vickers hardness reached HV_(0.25)1211.30and the residual compressive stress increased,while the nano-hardness increased to 14.07 from 5.31 GPa in the substrate.The micrometre scratch test results indicated that the plasticity and hardness of the nitrided layer changed in a gradient.The 50-μm effective hardened layer depth and surface compressive stress of the Ti6Al4V alloy were enhanced by the stacking faults.展开更多
SrMoO_(3)(SMO)thin films are deposited on LaAlO_(3)substrates by magnetron sputtering.The effects of ambient temperature on the structural,electrical,and optical properties of the films are investigated.As the tempera...SrMoO_(3)(SMO)thin films are deposited on LaAlO_(3)substrates by magnetron sputtering.The effects of ambient temperature on the structural,electrical,and optical properties of the films are investigated.As the temperature increases from 23℃ to 800℃,the SMO film exhibits high crystallinity and low electrical resistivity,and the real part of dielectric functions becomes less negative in the visible and near-IR wavelength range,and the epsilon near zero(ENZ)wavelength increases from460 nm to 890 nm.The optical loss of the SMO film is significantly lower than that of Au,and its plasmonic performance is comparable to or even higher than TiN in the temperature range of 23℃ to 600℃.These studies are critical for the design of high-temperature SMO-based plasmonic devices.展开更多
Environmental pollution caused by the presence of aromatic aldehydes and dyes in wastewater is a serious global concern. An effective strategy for the removal of these pollutants is their catalytic conversion, possibl...Environmental pollution caused by the presence of aromatic aldehydes and dyes in wastewater is a serious global concern. An effective strategy for the removal of these pollutants is their catalytic conversion, possibly to valuable compounds. Therefore, the design of efficient, stable and long-lifetime catalysts is a worthwhile research goal. Herein, we used nanofibrous carbon microspheres (NCM) derived from the carbohydrate chitin present in seafood waste, and characterized by interconnected nanofibrous networks and N/O-containing groups, as carriers for the manufacture of a highly dispersed, efficient and stable Pd nano-catalyst (mean diameter ca. 2.52 nm). Importantly, the carbonised chitin’s graphitized structure, defect presence and large surface area could promote the transport of electrons between NCM and Pd, thereby endowing NCM supported Pd catalyst with high catalytic activity. The NCM supported Pd catalyst was employed in the degradation of some representative dyes and the chemoselective hydrogenation of aromatic aldehydes;this species exhibited excellent catalytic activity and stability, as well as applicability to a broad range of aromatic aldehydes, suggesting its potential use in green industrial catalysis.展开更多
The structure and hydriding/dehydriding behaviors ofLa2Mgl7-10 wt.%Ni composite prepared by mechanical milling were investigated. Compared with the tin-milled sample, the as-milled alloys were ready to be activated an...The structure and hydriding/dehydriding behaviors ofLa2Mgl7-10 wt.%Ni composite prepared by mechanical milling were investigated. Compared with the tin-milled sample, the as-milled alloys were ready to be activated and the kinetics of hydrogen ab- sorption was relatively fast even at environmental temperature. The composite milled for 10 h absorbed 3.16 wt.% hydrogen within 100 s at 290 K. The kinetic mechanisms ofhydriding/dehydriding reactions were analyzed by using a new model. The results showed that hydrogenation processes for all composites were controlled by hydrogen diffusion and the minimum activation energy was 15.3 kJ/mol H2 for the composite milled for 10 h. Mechanical milling changed the dehydriding reaction rate-controlling step from surface penetration to diffusion and reduced the activation energy from 204.6 to 87.4 kJ/mol H2. The optimum milled duration was 5 h for desorption in our trials.展开更多
Current synthetic methods for the functionalization of pyridinium salts usually rely on transition metals,oxidants and/or photocatalysts.To date,no direct photolysis method exists under photocatalyst-,transition metal...Current synthetic methods for the functionalization of pyridinium salts usually rely on transition metals,oxidants and/or photocatalysts.To date,no direct photolysis method exists under photocatalyst-,transition metal-and oxidant-free conditions.We herein demonstrate the first direct photolysis of N-methoxypyridinium salts for the selective assembly of various pyridines by using a series of common feedstocks,including amine-boranes,unactivated alkanes,phosphine oxides,amides,silanes and aldehydes.展开更多
Currently,SmFeO_(3)-based sensors are an effective platform for detecting acetone gas.However,they require high operating temperatures,which increases energy consumption and safety hazards,and their response is low wh...Currently,SmFeO_(3)-based sensors are an effective platform for detecting acetone gas.However,they require high operating temperatures,which increases energy consumption and safety hazards,and their response is low when the gas concentration is at 10^(-9)(PPB),which cannot meet the requirements of using exhaled breath to pre-diagnose diabetes.Herein,Pd-SmFeO_(3)hollow nanotubes with an extremely high specific surface area and porosity were synthesized by electrospinning.After Pd doping,the specific surface area improved by more than two times,and the acetone response improved by more than three times.In addition,the response further improved by more than 1.5 times,and the optimum operating temperature reduced by 100℃under light irradiation.Moreover,the relative humidity adaptability,long-term stability,and selectivity of the material were significantly improved after Pd doping or light irradiation.Finally,the acetone concentration in a person’s exhaled breath was detected by a Pd-SmFeO_(3)-based gas sensor,and the error was less than 10%compared to that obtained by gas chromatography-mass spectrometry method.展开更多
基金supported by National Natural Science Foundation of China(52371095)Innovation Research Group of Universities in Chongqing(CXQT21030)+2 种基金Chongqing Talents:Exceptional Young Talents Project(CQYC201905100)Chongqing Youth Expert Studio,Chongqing Overseas Chinese Entrepreneurship and Innovation Support Program(cx2023117)Chongqing Natural Science Foundation Innovation and Development Joint Fund(CSTB 2022NS CQLZX0054)。
文摘Metal-air battery is an environmental friendly energy storage system with unique open structure.Magnesium(Mg)and its alloys have been extensively attempted as anodes for air batteries due to high theoretical energy density,low cost,and recyclability.However,the study on Mg-air battery(MAB)is still at the laboratory level currently,mainly owing to the low anodic efficiency caused by the poor corrosion resistance.In order to reduce corrosion losses and achieve optimal utilization efficiency of Mg anode,the design strategies are reviewed from microstructure perspectives.Firstly,the corrosion behaviors have been discussed,especially the negative difference effect derived by hydrogen evolution.Special attention is given to the effect of anode micro-structures on the MAB,which includes grain size,grain orientation,second phases,crystal structure,twins,and dislocations.For further improvement,the discharge performance,long period stacking ordered phase and its enhancing effect are considered.Meanwhile,given the current debates over Mg dendrites,the potential risk,the impact on discharge,and the elimination strategies are discussed.Microstructure control and single crystal would be promising ways for MAB anode.
基金financial support from the National Natural Science Foundation of China(Nos.22001248 and 22173103)the Fundamental Research Funds for the Central Universities and the University of the Chinese Academy of Sciences。
文摘We report the Lewis acid catalysis of aryldiazonium salts,and their Lewis acidity applications in photogeneration of aryl radicals under additive-,photocatalyst-and transition metal-free conditions.In this visible light-mediated transformation,the Lewis acidic character of aryldiazonium salts enables access to the photoactive charge transfer complex with dichalcogenides.The usefulness and versatility of this new protocol are demonstrated through the chalcogenation of a variety of aryldiazonium salts.
基金financially supported by the Science and Technology Foundation of Guizhou Province(No.[2020]1Z041)。
文摘The vacuum electromagnetic induction nitriding technology was applied to prepare a gradient nitrided layer on the surface of a Ti6Al4V alloy,which possesses TiN andα-Ti(N)phases.Moreover,transmission electron microscopy was conducted to confirm the presence of numerous high-density stacking faults caused by TiN and Ti_(2)N phases distributed on the surface of the alloy,along with a large number of basal stacking faults inside.A highdensity stacking fault led to serious distortion of lattice fringes.Lattice and numerous edge dislocations caused by defects were observed in the subsurface layer.For the surface layer,the Vickers hardness reached HV_(0.25)1211.30and the residual compressive stress increased,while the nano-hardness increased to 14.07 from 5.31 GPa in the substrate.The micrometre scratch test results indicated that the plasticity and hardness of the nitrided layer changed in a gradient.The 50-μm effective hardened layer depth and surface compressive stress of the Ti6Al4V alloy were enhanced by the stacking faults.
基金supported by the Science and Technology Research Project of Hubei Provincial Department of Education(No.D20202703)the Science and Technology Program of Guizhou Province(No.(2022)311)。
文摘SrMoO_(3)(SMO)thin films are deposited on LaAlO_(3)substrates by magnetron sputtering.The effects of ambient temperature on the structural,electrical,and optical properties of the films are investigated.As the temperature increases from 23℃ to 800℃,the SMO film exhibits high crystallinity and low electrical resistivity,and the real part of dielectric functions becomes less negative in the visible and near-IR wavelength range,and the epsilon near zero(ENZ)wavelength increases from460 nm to 890 nm.The optical loss of the SMO film is significantly lower than that of Au,and its plasmonic performance is comparable to or even higher than TiN in the temperature range of 23℃ to 600℃.These studies are critical for the design of high-temperature SMO-based plasmonic devices.
基金This work was supported by the Guizhou Provincial Science and Technology Foundation(Grant No.[2020]1Y212)the Science and Technology Top Talent Project of Guizhou Province(Grant No.[2021]029)+6 种基金the National Natural Science Foundation of China(Grant Nos.52063008 and 52103124)the Graduate Education Innovation Project of Guizhou Province(Grant No.[2020]099)the Guizhou Province Science and Technology Plan Project(Grant No.ZK[2021]Key 050)the Guizhou Key Laboratory of Inorganic Nonmetallic Functional Materials(Grant No.[2022]012)the Hundred Talents Project of Guizhou Province(Grant No.[2016]5673)the Lightweight Materials Engineering Research Center of the Education Department of Guizhou(Grant No.[2022]045)the Guizhou Province Science and Technology Support Plan(Grant Nos.[2020]4Y063 and[2021]04).
文摘Environmental pollution caused by the presence of aromatic aldehydes and dyes in wastewater is a serious global concern. An effective strategy for the removal of these pollutants is their catalytic conversion, possibly to valuable compounds. Therefore, the design of efficient, stable and long-lifetime catalysts is a worthwhile research goal. Herein, we used nanofibrous carbon microspheres (NCM) derived from the carbohydrate chitin present in seafood waste, and characterized by interconnected nanofibrous networks and N/O-containing groups, as carriers for the manufacture of a highly dispersed, efficient and stable Pd nano-catalyst (mean diameter ca. 2.52 nm). Importantly, the carbonised chitin’s graphitized structure, defect presence and large surface area could promote the transport of electrons between NCM and Pd, thereby endowing NCM supported Pd catalyst with high catalytic activity. The NCM supported Pd catalyst was employed in the degradation of some representative dyes and the chemoselective hydrogenation of aromatic aldehydes;this species exhibited excellent catalytic activity and stability, as well as applicability to a broad range of aromatic aldehydes, suggesting its potential use in green industrial catalysis.
基金Project supported by the Guizhou Nomarch Fund Project of Excellent Technology and Education Talents (201019)Specialties Projects funded for the Scientific Research Condition of Guizhou High-Level Talents (TZJF200927)
文摘The structure and hydriding/dehydriding behaviors ofLa2Mgl7-10 wt.%Ni composite prepared by mechanical milling were investigated. Compared with the tin-milled sample, the as-milled alloys were ready to be activated and the kinetics of hydrogen ab- sorption was relatively fast even at environmental temperature. The composite milled for 10 h absorbed 3.16 wt.% hydrogen within 100 s at 290 K. The kinetic mechanisms ofhydriding/dehydriding reactions were analyzed by using a new model. The results showed that hydrogenation processes for all composites were controlled by hydrogen diffusion and the minimum activation energy was 15.3 kJ/mol H2 for the composite milled for 10 h. Mechanical milling changed the dehydriding reaction rate-controlling step from surface penetration to diffusion and reduced the activation energy from 204.6 to 87.4 kJ/mol H2. The optimum milled duration was 5 h for desorption in our trials.
基金supported by the National Natural Science Foundation of China(E2240303,22001248)the Fundamental Research Funds for the Central Universities and the University of the Chinese Academy of Sciences.
文摘Current synthetic methods for the functionalization of pyridinium salts usually rely on transition metals,oxidants and/or photocatalysts.To date,no direct photolysis method exists under photocatalyst-,transition metal-and oxidant-free conditions.We herein demonstrate the first direct photolysis of N-methoxypyridinium salts for the selective assembly of various pyridines by using a series of common feedstocks,including amine-boranes,unactivated alkanes,phosphine oxides,amides,silanes and aldehydes.
基金financially supported by Shandong Natural Science Foundation(No.ZR2021QE265)the Fundamental Research Funds of Taishan University(No.Y01-2020015)+1 种基金the National Natural Science Foundation of China(Nos.61574098,61204051)Shandong Province Key Research and Development Program(No.2019GGX101016)。
文摘Currently,SmFeO_(3)-based sensors are an effective platform for detecting acetone gas.However,they require high operating temperatures,which increases energy consumption and safety hazards,and their response is low when the gas concentration is at 10^(-9)(PPB),which cannot meet the requirements of using exhaled breath to pre-diagnose diabetes.Herein,Pd-SmFeO_(3)hollow nanotubes with an extremely high specific surface area and porosity were synthesized by electrospinning.After Pd doping,the specific surface area improved by more than two times,and the acetone response improved by more than three times.In addition,the response further improved by more than 1.5 times,and the optimum operating temperature reduced by 100℃under light irradiation.Moreover,the relative humidity adaptability,long-term stability,and selectivity of the material were significantly improved after Pd doping or light irradiation.Finally,the acetone concentration in a person’s exhaled breath was detected by a Pd-SmFeO_(3)-based gas sensor,and the error was less than 10%compared to that obtained by gas chromatography-mass spectrometry method.