The development of high-energy-density Li-ion batteries is hindered by the irreversible capacity loss during the initial charge-discharge process.Therefore,pre-lithiation technology has emerged in the past few decades...The development of high-energy-density Li-ion batteries is hindered by the irreversible capacity loss during the initial charge-discharge process.Therefore,pre-lithiation technology has emerged in the past few decades as a powerful method to supplement the undesired lithium loss,thereby maximizing the energy utilization of LIBs and extending their cycle life.Lithium oxalate(Li_(2)C_(2)O_(4)),with a high lithium content and excellent air stability,has been considered one of the most promising materials for lithium compensation.However,the sluggish electrochemical decomposition kinetics of the material severely hinders its further commercial application.Here,we introduce a recrystallization strategy combined with atomic Ni catalysts to modulate the mass transport and decomposition reaction kinetics.The decomposition potential of Li_(2)C_(2)O_(4)is significantly decreased from~4.90V to~4.30V with a high compatibility with the current battery systems.In compared to the bare NCM//Li cell,the Ni/N-rGO and Li_(2)C_(2)O_(4)composite(Ni-LCO)modified cell releases an extra capacity of~11.7%.Moreover,this ratio can be magnified in the NCM//SiOx full cell,resulting in a 30.4%higher reversible capacity.Overall,this work brings the catalytic paradigm into the pre-lithiation technology,which opens another window for the development of high-energy-density battery systems.展开更多
In this work,mechanical alloying of the alternating stacked pure Al and Zn thin foils was accomplished via high-pressure torsion(HPT).In the alloyed Al-Zn system,an exotic phase transformation from hexagonal close-pac...In this work,mechanical alloying of the alternating stacked pure Al and Zn thin foils was accomplished via high-pressure torsion(HPT).In the alloyed Al-Zn system,an exotic phase transformation from hexagonal close-packed(HCP)to face-centered cubic(FCC)was identified.The atomic-scale evolution process and underlying mechanism of phase transformation down to atomic scale are provided by molecular dynamics simulation and high-resolution transmission electron microscopy.The HCP→FCC phase transformation was attributed to the sliding of Shockley partial dislocations generated at the Al-Zn grain boundaries,which resulted in an[2110][011]and(0001)/(111)orientation relationship between the two phases.This work provides a new approach for the in-depth study of the solid phase transformation of Al-Zn alloys and also shed lights on understanding the mechanical properties of the HPT processed Al-Zn alloys.展开更多
To the Editor:Genomic instability is a hallmark of cancer,with increasing genetic changes and DNA damage.The accumulated mutations in the tumor genome can generate neoantigens,which can trigger an antitumor immune res...To the Editor:Genomic instability is a hallmark of cancer,with increasing genetic changes and DNA damage.The accumulated mutations in the tumor genome can generate neoantigens,which can trigger an antitumor immune response.Moreover,as a consequence of genomic instability,the leakage of nuclear DNA can directly alert the immune system to the presence of malignant cells.Cyclic guanosine monophosphate-adenosine monophosphate synthase(cGAS)is a major DNA sensor that triggers the innate immune response.[1]The accumulation of doublestranded DNA fragments in the cytoplasm can directly bind to cGAS,functioning as an activator or stimulator of interferon genes(STING).STING acts as a signaling platform to recruit TANK-binding kinase 1(TBK1)and interferon regulatory factor 3(IRF3)for phosphorylation.Phosphorylated IRF3 translocates to the nuclei,where it functions as a transcription factor to promote the expression of type I interferon(IFN)and immune-stimulated cytokines.This leads to the migration and activation of various immune cells.展开更多
Visible-light-driven photocatalysis has great potential in environmental remediation and organic synthesis.Rational design and regulation of the reaction interfacial microenvironment is critical for photocatalytic per...Visible-light-driven photocatalysis has great potential in environmental remediation and organic synthesis.Rational design and regulation of the reaction interfacial microenvironment is critical for photocatalytic performance,yet challenging.We report here a highly efficient photocatalytic system based on hydrophobic TiO_(2) porous(H-OTP)film for visible-light-driven dye-sensitized photo-oxidation.Such interface architecture design enhances the adsorption capability of organic dyes and enables the formation of air trapped triphase reaction interface microenvironment as confirmed via three-dimensional(3D)laser scanning confocal microscopy.Based on this interface architecture,the concentrations of O_(2) and organic molecule at the local reaction zone are both significantly increased,which promotes the generation of reactive oxygen species(·O_(2)^(−)and·OH),and enhances the photocatalytic performance in terms of both kinetics and organic mineralization efficiency.This study highlights the importance of interface microenvironment design and reveals an effective way to develop highly efficient photocatalytic systems.展开更多
The Li-O_(2) battery(LOB)has attracted growing interest,including for its great potential in next-generation energy storage systems due to its extremely high theoretical specific capacity.However,a series of challenge...The Li-O_(2) battery(LOB)has attracted growing interest,including for its great potential in next-generation energy storage systems due to its extremely high theoretical specific capacity.However,a series of challenges have seriously hindered LOB development,such as sluggish kinetics during the oxygen reduction and oxygen evolution reactions(ORR/OER)at the cathode,the formation of lithium dendrites,and undesirable corrosion at the lithium metal anode.Herein,we propose a strategy based on the ultra-low loading of atomic Ni catalysts to simultaneously boost the ORR/OER at the cathode while stabilizing the Li metal anode.The resultant LOB delivers a superior discharge capacity(>16,000 mAh g^(-1)),excellent long-term cycling stability(>200 cycles),and enhanced high rate capability(>300 cycles@500 mA g^(-1)).The working mechanisms of these atomic Ni catalysts are revealed through carefully designed in situ experiments and theoretical calculations.This work provides a novel research paradigm for designing high-performance LOBs that are useable in practical applications.展开更多
Alloying-type anode materials are considered promising candidates for next-generation alkali-ion batteries.However,they face significant challenges owing to severe volume variations and sluggish kinetics,which hinder t...Alloying-type anode materials are considered promising candidates for next-generation alkali-ion batteries.However,they face significant challenges owing to severe volume variations and sluggish kinetics,which hinder their practical applications.To address these issues,we propose a universal synthetic strategy,which can realize the facile synthesis of various alloying-type anode materials composed of a porous carbon matrix with uniformly embedded nanoparticles(Sb,Bi,or Sn).Besides,we construct the interactions among active materials,electrolyte compositions,and the resulting interface chemistries.This understanding assists in establishing balanced kinetics and stability.As a result,the fabricated battery cells based on the above strategy demonstrate high reversible capacity(515.6 mAh g1),long cycle life(200 cycles),and excellent high-rate capability(at 5.0 C).Additionally,it shows improved thermal stability at 45 and 60C.Moreover,our alloying-type anodes exhibit significant potential for constructing a 450 Wh kg1 battery system.This proposed strategy could boost the development of alloying-type anode materials,aligning with the future demands for low-cost,high stability,high safety,wide-temperature,and fast-charging battery systems.展开更多
The low energy efficiency and poor cycle stability arising from the high aggressivity of discharge products toward organic electrolytes limit the practical applications of Li-O_(2)batteries(LOBs).Compared with the typ...The low energy efficiency and poor cycle stability arising from the high aggressivity of discharge products toward organic electrolytes limit the practical applications of Li-O_(2)batteries(LOBs).Compared with the typical discharge product Li_(2)O_(2),LiOH shows better chemical and electrochemical stability.In this study,a free-standing cathode composed of hydrangea-likeδ-MnO_(2)with Ag nanoparticles(NPs)embedded in carbon paper(CP)(Ag/δ-MnO_(2)@CP)is fabricated and used as the catalyst for the reversible formation and decomposition of LiOH.The possible discharge mechanism is investigated by in situ Raman measurement and density functional theory calculation.Results confirm thatδ-MnO_(2)dominantly catalyzes the conversion reaction of discharge intermediate LiO_(2)*to LiOH and that Ag particles promote its catalytic ability.In the presence of Ag/δ-MnO_(2)@CP cathode,the LOB exhibits enhanced specific capacity and a high discharge voltage plateau under humid O_(2)atmosphere.At a current density of 200 mA g^(−1),the LOB with the Ag/δ-MnO_(2)@CP cathode presents an overpotential of 0.5 V and an ultra-long cycle life of 867 cycles with a limited specific capacity of 500 mA h g^(−1).This work provides a fresh view on the role of solid catalysts in LOBs and promotes the development of LOBs based on LiOH discharge product for practical applications.展开更多
The hydrogen evolution reaction(HER)in alkaline water electrolysis faces significant kinetic and thermodynamic challenges that hinder its efficiency and scalability for sustainable hydrogen production.Herein,we employ...The hydrogen evolution reaction(HER)in alkaline water electrolysis faces significant kinetic and thermodynamic challenges that hinder its efficiency and scalability for sustainable hydrogen production.Herein,we employed an in-situ synthesis strategy to incorporate H atoms into the PdRu alloy lattice to form H_(Inc)-PdRu electrocatalyst,thereby modulating its electronic structure and enhancing its alkaline HER performance.We demonstrate that the incorporation of H atoms significantly improves electrocatalytic activity,achieving a remarkably low overpotential of 25 mV at 10 mA cm^(-2)compared with the Pd,Ru and PdRu catalysts while maintaining robust catalyst stability.Operando spectroscopic analysis indicates that H insertion into the H_(Inc)-PdRu electrocatalyst enhances the availability of H_(2)O^(*)at the surface,promoting water dissociation at the active sites.Theoretical calculations proposed that the co-incorporating H and Ru atoms induces s-d orbital coupling within the Pd lattices,effectively weakening hydrogen adsorption strength and optimizing the alkaline HER energetics.This work presents a facile approach for the rational design of bimetallic electrocatalysts for efficient and stable alkaline water electrolysis for renewable hydrogen production.展开更多
The Dynamical-microphysical-electrical Processes in Severe Thunderstorms and Lightning Hazards(STORM973)project conducted coordinated comprehensive field observations of thunderstorms in the Beijing metropolitan regio...The Dynamical-microphysical-electrical Processes in Severe Thunderstorms and Lightning Hazards(STORM973)project conducted coordinated comprehensive field observations of thunderstorms in the Beijing metropolitan region(BMR)during the warm season from 2014 to 2018.The aim of the project was to understand how dynamical,microphysical and electrical processes interact in severe thunderstorms in the BMR,and how to assimilate lightning data in numerical weather prediction models to improve severe thunderstorm forecasts.The platforms used in the field campaign included the Beijing Lightning Network(BLNET,consisting of 16 stations),2 X-band dual linear polarimetric Doppler radars,and 4 laser raindrop spectrometers.The collaboration also made use of the China Meteorological Administration’s mesoscale meteorological observation network in the Beijing-Tianjin-Hebei region.Although diverse thunderstorm types were documented,it was found that squall lines and multicell storms were the two major categories of severe thunderstorms with frequent lightning activity and extreme rainfall or unexpected local short-duration heavy rainfall resulting in inundations in the central urban area,influenced by the terrain and environmental conditions.The flash density maximums were found in eastern Changping District,central and eastern Shunyi District,and the central urban area of Beijing,suggesting that the urban heat island effect has a crucial role in the intensification of thunderstorms over Beijing.In addition,the flash rate associated with super thunderstorms can reach hundreds of flashes per minute in the central city regions.The super(5%of the total),strong(35%),and weak(60%)thunderstorms contributed about 37%,56%,and 7%to the total flashes in the BMR,respectively.Owing to the close connection between lightning activity and the thermodynamic and microphysical characteristics of the thunderstorms,the lightning flash rate can be used as an indicator of severe weather events,such as hail and short-duration heavy rainfall.Lightning data can also be assimilated into numerical weather prediction models to help improve the forecasting of severe convection and precipitation at the cloud-resolved scale,through adjusting or correcting the thermodynamic and microphysical parameters of the model.展开更多
Due to the increasing demand and wide applications of lithium-ion batteries,higher requirements have been placed on the energy density and safety.Polymer solid-state electrolytes have gained significant popularity due...Due to the increasing demand and wide applications of lithium-ion batteries,higher requirements have been placed on the energy density and safety.Polymer solid-state electrolytes have gained significant popularity due to their excellent interface compatibility and safety.However,their applications have been greatly restricted by the high crystallinity at room temperature,which hinders the transport of lithium ions.Herein,we utilize inorganic tubular fillers with abundant lone-pair atoms to reduce the crystallinity of the polyethylene oxide(PEO)solid-state electrolyte membrane and improve its ionic conductivity at room temperature,enabling stable operation of the battery.The tubular lone-pair-rich inorganic fillers play a key role in providing avenues for both internal and external charge transportation.The surface lone-pair electrons facilitate the dissociation and transport of lithium ions,while the internally tubular electron-rich layer attracts ions into the cavities,further enhancing the ion transport.After 100 cycles at room temperature,the lithium battery loaded with this solid-state electrolyte membrane delivers a specific capacity of 141.6 mAh·g−1,which is 51.3%higher compared to the membrane without the fillers.展开更多
Regularly assembled structures of nanowires, such as aligned arrays, junctions and interconnected networks, have great potential for the applications in logical circuits, address decoders, photoelectronic devices and ...Regularly assembled structures of nanowires, such as aligned arrays, junctions and interconnected networks, have great potential for the applications in logical circuits, address decoders, photoelectronic devices and transparent electrodes. However, for now it is still lack of effective approaches for constructing nanowire bifurcated junctions and crosslinked networks with ordered orientations and high quality. Herein, we report the controlled growth of Bi2S3 semiconductor nanowire bifurcated junctions and crosslinked networks with well-aligned directions and high crystalline degree by utilizing the proportional lattice match between nanowires and substrates. Taking advantages of the “tip-to-stem splice” assembly of individual nanowires, the precise orientation alignments of Bi2S3 semiconductor nanowire bifurcated junctions and crosslinked networks were successfully realized. The controlled growth mechanism and structural evolution process have been elucidated by detailed atomic structure characterizations and modeling. The highly crystal quality and direct energy bandgap of as-assembled photodetectors based on individual bismuth sulfide nanowires enabled high photoresponsivity and fast switch time under light illumination. The three-terminal devices based on nanowire bifurcated junctions present rapid carrier transport across the junction. The flexible photodetectors based on nanowire crosslinked networks show very minimal decay of photocurrent after long-term bending test. This work may provide new insights for the guided construction and regular assembly of low-dimensional ordered functional nanostructures towards advanced nanotechnologies.展开更多
The fundamental understanding of the mechanism underlying the early stages of crystallization of hexagonal-close-packed(hcp)nanocrystals is crucial for their synthesis with desired properties,but it remains a signific...The fundamental understanding of the mechanism underlying the early stages of crystallization of hexagonal-close-packed(hcp)nanocrystals is crucial for their synthesis with desired properties,but it remains a significant challenge.Here,we report using in situ liquid cell transmission electron microscopy(TEM)to directly capture the dynamic nucleation process and track the real-time growth pathway of hcp Ni nanocrystals at the atomic scale.It is demonstrated that the growth of amorphous-phase-mediated hcp Ni nanocrystals is from the metal-rich liquid phases.In addition,the reshaped preatomic facet development of a single nanocrystal is also imaged.Theoretical calculations further identify the non-classical features of hcp Ni crystallization.These discoveries could enrich the nucleation and growth model theory and provide useful information for the rational design of synthesis pathways of hcp nanocrystals.展开更多
基金supported by National Natural Science Foundation of China(Grant No.52002094)Guangdong Basic and Applied Basic Research Foundation(Grant No.2019A1515110756)+2 种基金Shenzhen Science and Technology Program(Grant No.JCYJ20210324121411031,JSGG202108021253804014,RCBS20210706092218040)the Shenzhen Steady Support Plan(GXWD20221030205923001,GXWD20201230155427003-20200824103000001)School Research Startup Expenses of Harbin Institute of Technology(Shenzhen)(Grant No.DD29100027,DD45001022).
文摘The development of high-energy-density Li-ion batteries is hindered by the irreversible capacity loss during the initial charge-discharge process.Therefore,pre-lithiation technology has emerged in the past few decades as a powerful method to supplement the undesired lithium loss,thereby maximizing the energy utilization of LIBs and extending their cycle life.Lithium oxalate(Li_(2)C_(2)O_(4)),with a high lithium content and excellent air stability,has been considered one of the most promising materials for lithium compensation.However,the sluggish electrochemical decomposition kinetics of the material severely hinders its further commercial application.Here,we introduce a recrystallization strategy combined with atomic Ni catalysts to modulate the mass transport and decomposition reaction kinetics.The decomposition potential of Li_(2)C_(2)O_(4)is significantly decreased from~4.90V to~4.30V with a high compatibility with the current battery systems.In compared to the bare NCM//Li cell,the Ni/N-rGO and Li_(2)C_(2)O_(4)composite(Ni-LCO)modified cell releases an extra capacity of~11.7%.Moreover,this ratio can be magnified in the NCM//SiOx full cell,resulting in a 30.4%higher reversible capacity.Overall,this work brings the catalytic paradigm into the pre-lithiation technology,which opens another window for the development of high-energy-density battery systems.
基金funded by the National Natural Science Foundation of China(Grant Nos.51905215,U22A20187)the Major Scientific and Technological Innovation Project of Shandong Province of China(Grant No.2019JZZY020111).
文摘In this work,mechanical alloying of the alternating stacked pure Al and Zn thin foils was accomplished via high-pressure torsion(HPT).In the alloyed Al-Zn system,an exotic phase transformation from hexagonal close-packed(HCP)to face-centered cubic(FCC)was identified.The atomic-scale evolution process and underlying mechanism of phase transformation down to atomic scale are provided by molecular dynamics simulation and high-resolution transmission electron microscopy.The HCP→FCC phase transformation was attributed to the sliding of Shockley partial dislocations generated at the Al-Zn grain boundaries,which resulted in an[2110][011]and(0001)/(111)orientation relationship between the two phases.This work provides a new approach for the in-depth study of the solid phase transformation of Al-Zn alloys and also shed lights on understanding the mechanical properties of the HPT processed Al-Zn alloys.
基金founded by Beijing Xisike Clinical Oncology Research Foundation(No.Y-2019AZMS-0439).
文摘To the Editor:Genomic instability is a hallmark of cancer,with increasing genetic changes and DNA damage.The accumulated mutations in the tumor genome can generate neoantigens,which can trigger an antitumor immune response.Moreover,as a consequence of genomic instability,the leakage of nuclear DNA can directly alert the immune system to the presence of malignant cells.Cyclic guanosine monophosphate-adenosine monophosphate synthase(cGAS)is a major DNA sensor that triggers the innate immune response.[1]The accumulation of doublestranded DNA fragments in the cytoplasm can directly bind to cGAS,functioning as an activator or stimulator of interferon genes(STING).STING acts as a signaling platform to recruit TANK-binding kinase 1(TBK1)and interferon regulatory factor 3(IRF3)for phosphorylation.Phosphorylated IRF3 translocates to the nuclei,where it functions as a transcription factor to promote the expression of type I interferon(IFN)and immune-stimulated cytokines.This leads to the migration and activation of various immune cells.
基金supported by the National Key R&D Program of China(2019YFA0709200)the National Natural Science Foundation of China(21988102,51772198,21975171)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Visible-light-driven photocatalysis has great potential in environmental remediation and organic synthesis.Rational design and regulation of the reaction interfacial microenvironment is critical for photocatalytic performance,yet challenging.We report here a highly efficient photocatalytic system based on hydrophobic TiO_(2) porous(H-OTP)film for visible-light-driven dye-sensitized photo-oxidation.Such interface architecture design enhances the adsorption capability of organic dyes and enables the formation of air trapped triphase reaction interface microenvironment as confirmed via three-dimensional(3D)laser scanning confocal microscopy.Based on this interface architecture,the concentrations of O_(2) and organic molecule at the local reaction zone are both significantly increased,which promotes the generation of reactive oxygen species(·O_(2)^(−)and·OH),and enhances the photocatalytic performance in terms of both kinetics and organic mineralization efficiency.This study highlights the importance of interface microenvironment design and reveals an effective way to develop highly efficient photocatalytic systems.
基金supported by National Natural Science Foundation of China(Grant No.52002094,22479037)Guangdong Basic and Applied Basic Research Foundation(Grant No.2019A1515110756)+2 种基金Shenzhen Science and Technology Program(Grant No.JCYJ20210324121411031,JSGG202108021253804014,RCBS20210706092218040)the Shenzhen Steady Support Plan(GXWD20221030205923001,GXWD20201230155427003-20200824103000001)State Key Laboratory of Precision Welding&Joining of Materials and Structures(Grant Nos.24-Z-17,24-T-08).
文摘The Li-O_(2) battery(LOB)has attracted growing interest,including for its great potential in next-generation energy storage systems due to its extremely high theoretical specific capacity.However,a series of challenges have seriously hindered LOB development,such as sluggish kinetics during the oxygen reduction and oxygen evolution reactions(ORR/OER)at the cathode,the formation of lithium dendrites,and undesirable corrosion at the lithium metal anode.Herein,we propose a strategy based on the ultra-low loading of atomic Ni catalysts to simultaneously boost the ORR/OER at the cathode while stabilizing the Li metal anode.The resultant LOB delivers a superior discharge capacity(>16,000 mAh g^(-1)),excellent long-term cycling stability(>200 cycles),and enhanced high rate capability(>300 cycles@500 mA g^(-1)).The working mechanisms of these atomic Ni catalysts are revealed through carefully designed in situ experiments and theoretical calculations.This work provides a novel research paradigm for designing high-performance LOBs that are useable in practical applications.
基金supported by the National Natural Science Foundation of China(52002094)Guangdong Basic and Applied Basic Research Foundation(2019A1515110756)+1 种基金Shenzhen Science and Technology Program(JCYJ20210324121411031,JSGG202108021253804014,RCBS 20210706092218040,GXWD20221030205923001,and GXWD20201230155427003-20200824103000001)State Key Laboratory of Precision Welding&Joining of Materials and Structures(Nos.24-Z-17,24-T-08).
文摘Alloying-type anode materials are considered promising candidates for next-generation alkali-ion batteries.However,they face significant challenges owing to severe volume variations and sluggish kinetics,which hinder their practical applications.To address these issues,we propose a universal synthetic strategy,which can realize the facile synthesis of various alloying-type anode materials composed of a porous carbon matrix with uniformly embedded nanoparticles(Sb,Bi,or Sn).Besides,we construct the interactions among active materials,electrolyte compositions,and the resulting interface chemistries.This understanding assists in establishing balanced kinetics and stability.As a result,the fabricated battery cells based on the above strategy demonstrate high reversible capacity(515.6 mAh g1),long cycle life(200 cycles),and excellent high-rate capability(at 5.0 C).Additionally,it shows improved thermal stability at 45 and 60C.Moreover,our alloying-type anodes exhibit significant potential for constructing a 450 Wh kg1 battery system.This proposed strategy could boost the development of alloying-type anode materials,aligning with the future demands for low-cost,high stability,high safety,wide-temperature,and fast-charging battery systems.
基金financially supported by the National Key R&D Program of China(2019YFA0709200)the National Natural Science Foundation of China(21988102,51772198,21975171)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
基金financially supported by the High-level Talents’Discipline Construction Fund of Shandong University(31370089963078)the School Research Startup Expenses of Harbin Institute of Technology(Shenzhen)(20190037 and 20210028)+3 种基金China Postdoctoral Science Foundation(2019M661276 and 2021T140150)Guangdong Basic and Applied Basic Research Foundation(2019A1515110756)the National Natural Science Foundation of China(52002094)the Open Fund of Guangdong Provincial Key laboratory of Advanced Energy Storage Materials(AESM202107)。
文摘The low energy efficiency and poor cycle stability arising from the high aggressivity of discharge products toward organic electrolytes limit the practical applications of Li-O_(2)batteries(LOBs).Compared with the typical discharge product Li_(2)O_(2),LiOH shows better chemical and electrochemical stability.In this study,a free-standing cathode composed of hydrangea-likeδ-MnO_(2)with Ag nanoparticles(NPs)embedded in carbon paper(CP)(Ag/δ-MnO_(2)@CP)is fabricated and used as the catalyst for the reversible formation and decomposition of LiOH.The possible discharge mechanism is investigated by in situ Raman measurement and density functional theory calculation.Results confirm thatδ-MnO_(2)dominantly catalyzes the conversion reaction of discharge intermediate LiO_(2)*to LiOH and that Ag particles promote its catalytic ability.In the presence of Ag/δ-MnO_(2)@CP cathode,the LOB exhibits enhanced specific capacity and a high discharge voltage plateau under humid O_(2)atmosphere.At a current density of 200 mA g^(−1),the LOB with the Ag/δ-MnO_(2)@CP cathode presents an overpotential of 0.5 V and an ultra-long cycle life of 867 cycles with a limited specific capacity of 500 mA h g^(−1).This work provides a fresh view on the role of solid catalysts in LOBs and promotes the development of LOBs based on LiOH discharge product for practical applications.
文摘The hydrogen evolution reaction(HER)in alkaline water electrolysis faces significant kinetic and thermodynamic challenges that hinder its efficiency and scalability for sustainable hydrogen production.Herein,we employed an in-situ synthesis strategy to incorporate H atoms into the PdRu alloy lattice to form H_(Inc)-PdRu electrocatalyst,thereby modulating its electronic structure and enhancing its alkaline HER performance.We demonstrate that the incorporation of H atoms significantly improves electrocatalytic activity,achieving a remarkably low overpotential of 25 mV at 10 mA cm^(-2)compared with the Pd,Ru and PdRu catalysts while maintaining robust catalyst stability.Operando spectroscopic analysis indicates that H insertion into the H_(Inc)-PdRu electrocatalyst enhances the availability of H_(2)O^(*)at the surface,promoting water dissociation at the active sites.Theoretical calculations proposed that the co-incorporating H and Ru atoms induces s-d orbital coupling within the Pd lattices,effectively weakening hydrogen adsorption strength and optimizing the alkaline HER energetics.This work presents a facile approach for the rational design of bimetallic electrocatalysts for efficient and stable alkaline water electrolysis for renewable hydrogen production.
基金supported by the National Natural Science Foundation of China(Grant Nos.41630425,41671144074)the Key Research Program of Frontier Science,CAS(Grant No.QYZDJ-SSW-DQC007)the National Key Basic Research Program of China(Grant No.2014CB441401)。
文摘The Dynamical-microphysical-electrical Processes in Severe Thunderstorms and Lightning Hazards(STORM973)project conducted coordinated comprehensive field observations of thunderstorms in the Beijing metropolitan region(BMR)during the warm season from 2014 to 2018.The aim of the project was to understand how dynamical,microphysical and electrical processes interact in severe thunderstorms in the BMR,and how to assimilate lightning data in numerical weather prediction models to improve severe thunderstorm forecasts.The platforms used in the field campaign included the Beijing Lightning Network(BLNET,consisting of 16 stations),2 X-band dual linear polarimetric Doppler radars,and 4 laser raindrop spectrometers.The collaboration also made use of the China Meteorological Administration’s mesoscale meteorological observation network in the Beijing-Tianjin-Hebei region.Although diverse thunderstorm types were documented,it was found that squall lines and multicell storms were the two major categories of severe thunderstorms with frequent lightning activity and extreme rainfall or unexpected local short-duration heavy rainfall resulting in inundations in the central urban area,influenced by the terrain and environmental conditions.The flash density maximums were found in eastern Changping District,central and eastern Shunyi District,and the central urban area of Beijing,suggesting that the urban heat island effect has a crucial role in the intensification of thunderstorms over Beijing.In addition,the flash rate associated with super thunderstorms can reach hundreds of flashes per minute in the central city regions.The super(5%of the total),strong(35%),and weak(60%)thunderstorms contributed about 37%,56%,and 7%to the total flashes in the BMR,respectively.Owing to the close connection between lightning activity and the thermodynamic and microphysical characteristics of the thunderstorms,the lightning flash rate can be used as an indicator of severe weather events,such as hail and short-duration heavy rainfall.Lightning data can also be assimilated into numerical weather prediction models to help improve the forecasting of severe convection and precipitation at the cloud-resolved scale,through adjusting or correcting the thermodynamic and microphysical parameters of the model.
基金supported by School Research Startup Expenses of Harbin Institute of Technology(Shenzhen)(Nos.DD29100027 and DD45001022)the National Natural Science Foundation of China(No.52002094)+1 种基金Shenzhen Science and Technology Program(Nos.JCYJ20210324121411031,JSGG202108021253804014,and RCBS20210706092218040)the Open Fund of the Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials(No.asem202107).
文摘Due to the increasing demand and wide applications of lithium-ion batteries,higher requirements have been placed on the energy density and safety.Polymer solid-state electrolytes have gained significant popularity due to their excellent interface compatibility and safety.However,their applications have been greatly restricted by the high crystallinity at room temperature,which hinders the transport of lithium ions.Herein,we utilize inorganic tubular fillers with abundant lone-pair atoms to reduce the crystallinity of the polyethylene oxide(PEO)solid-state electrolyte membrane and improve its ionic conductivity at room temperature,enabling stable operation of the battery.The tubular lone-pair-rich inorganic fillers play a key role in providing avenues for both internal and external charge transportation.The surface lone-pair electrons facilitate the dissociation and transport of lithium ions,while the internally tubular electron-rich layer attracts ions into the cavities,further enhancing the ion transport.After 100 cycles at room temperature,the lithium battery loaded with this solid-state electrolyte membrane delivers a specific capacity of 141.6 mAh·g−1,which is 51.3%higher compared to the membrane without the fillers.
基金This work was supported by the National Key R&D Program(Nos.2017YFA0208200 and 2016YFB0700600)the Fundamental Research Funds for the Central Universities(No.0205-14380219)+2 种基金the Projects of the National Natural Science Foundation of China(NSFC)(Nos.21872069,51761135104,and 21573108)the Natural Science Foundation of Jiangsu Province(No.BK20180008)the High-Level Innovation and Entrepreneurship Project of Jiangsu Province of China.
文摘Regularly assembled structures of nanowires, such as aligned arrays, junctions and interconnected networks, have great potential for the applications in logical circuits, address decoders, photoelectronic devices and transparent electrodes. However, for now it is still lack of effective approaches for constructing nanowire bifurcated junctions and crosslinked networks with ordered orientations and high quality. Herein, we report the controlled growth of Bi2S3 semiconductor nanowire bifurcated junctions and crosslinked networks with well-aligned directions and high crystalline degree by utilizing the proportional lattice match between nanowires and substrates. Taking advantages of the “tip-to-stem splice” assembly of individual nanowires, the precise orientation alignments of Bi2S3 semiconductor nanowire bifurcated junctions and crosslinked networks were successfully realized. The controlled growth mechanism and structural evolution process have been elucidated by detailed atomic structure characterizations and modeling. The highly crystal quality and direct energy bandgap of as-assembled photodetectors based on individual bismuth sulfide nanowires enabled high photoresponsivity and fast switch time under light illumination. The three-terminal devices based on nanowire bifurcated junctions present rapid carrier transport across the junction. The flexible photodetectors based on nanowire crosslinked networks show very minimal decay of photocurrent after long-term bending test. This work may provide new insights for the guided construction and regular assembly of low-dimensional ordered functional nanostructures towards advanced nanotechnologies.
基金supported by the National Natural Science Foundation of China(Nos.22001083,52072323,and 52122211)the“Double-First Class”Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen University.J.Y.L.thanks the Research Startup Fund from Harbin Institute of Technology(Shenzhen)with the project number University(No.20210028)the Shenzhen Steady Support Plan(No.GXWD20201230155427003-20200824103000001).
文摘The fundamental understanding of the mechanism underlying the early stages of crystallization of hexagonal-close-packed(hcp)nanocrystals is crucial for their synthesis with desired properties,but it remains a significant challenge.Here,we report using in situ liquid cell transmission electron microscopy(TEM)to directly capture the dynamic nucleation process and track the real-time growth pathway of hcp Ni nanocrystals at the atomic scale.It is demonstrated that the growth of amorphous-phase-mediated hcp Ni nanocrystals is from the metal-rich liquid phases.In addition,the reshaped preatomic facet development of a single nanocrystal is also imaged.Theoretical calculations further identify the non-classical features of hcp Ni crystallization.These discoveries could enrich the nucleation and growth model theory and provide useful information for the rational design of synthesis pathways of hcp nanocrystals.
