Surface morphology and deuterium retention in ultrafine-grained tungsten fabricated by equal-channel angular pressing（ECAP） have been examined after exposure to a low energy,high-flux deuterium（D） plasma at fluenc...Surface morphology and deuterium retention in ultrafine-grained tungsten fabricated by equal-channel angular pressing（ECAP） have been examined after exposure to a low energy,high-flux deuterium（D） plasma at fluences of 3×10^24 D/m^2 and 1×10^25 D/m^2 in a temperature range of 100 ℃-150 ℃.The methods used were scanning electron microscopy（SEM） and thermal desorption spectroscopy（TDS）.Sparse and small blisters（0.1 μm） were observed by SEM after D plasma irradiation on every irradiated surface;yet they did not exhibit significant structure or plasma fluence dependence.Larger blisters or protrusions appeared after subsequent TDS heating up to 1000 ℃.The TDS results showed a single D desorption peak at 220℃ for all samples and the D retention increased with increasing numbers of extrusion passes,i.e.,the decrease of grain sizes.The increased D retention in this low temperature range should be attributed to the faster diffusion of D along the larger volume fraction of grain boundaries introduced by ECAP.展开更多
In the past two decades,the field of surface-enhanced Raman scattering (SERS) has flourished and many rational strategies have been reported for the successful construction of SERS substrates.However,it still lacks th...In the past two decades,the field of surface-enhanced Raman scattering (SERS) has flourished and many rational strategies have been reported for the successful construction of SERS substrates.However,it still lacks the mass-production and programmability for practical applications with arbitrary configurations,and it is highly desirable to develop SERS substrates with strong signal enhancement,large-scale surface area,easy fabrication and low cost.Herein,we demonstrate a large-area fabrication (1.5 m × 5 m) of low-cost (18.8 dollars per square meter),highly sensitive,flexible and transparent SERS substrate by a simple solution process.The high sensitivity of SERS substrate using 3,3'-diethylthiatricarbocyanine iodide (DTTCI) as probe molecules is strongly dependent on the density and diameter of gold nanoparticles (NPs) on the surface of nylon mesh with the best enhancement factor (EF) of 9.17 × 10^10 and the SERS detection limit of DTTCI molecules is as low as 10-14 M which shows no obvious degradation even after 10,000 cycles of fatigue test,high temperature (above than 160 ℃) and acid-alkali treatment,indicating their excellent stability for the performance in all climates.展开更多
Magnesium calcite(Mg-calcite)mesocrystal is widespread in the biominerals with specific functions.Until now,it remains challenging to obtain Mg-calcite mesocrystals without organic additives and the formation mechanis...Magnesium calcite(Mg-calcite)mesocrystal is widespread in the biominerals with specific functions.Until now,it remains challenging to obtain Mg-calcite mesocrystals without organic additives and the formation mechanism of Mg-calcite mesocrystals in the ocean is not clear yet.We report here the synthesis of corn-like Mg-calcite mesocrystals from pure amorphous calcium carbonate(ACC)via a facile method only by using Ca^(2+)and Mg^(2+).The obtained Mg-calcite is composed of many nanocubes with common crystallographic orientation,which shows very good single crystal feature.In the crystallizing procedure,the ACC nanospheres rapidly agglomerate into Mg-calcite corn-like mesocrystal by oriented attachment(OA)in a certain direction,which belongs to the non-classical nucleation.By this method,the molar ratio of Ca^(2+)and Mg^(2+)plays a vital role in the whole crystallization procedure,which may shed a new light on disclosing the mechanism behind for the effect of seawater in the formation of biological Mg-calcite in nature.展开更多
Nanowire devices have attracted considerable attention because of their unique structure and novel properties, and have opened up significant development opportunities. However, not many studies have focused on their ...Nanowire devices have attracted considerable attention because of their unique structure and novel properties, and have opened up significant development opportunities. However, not many studies have focused on their stability and durability under practical conditions, which limits the rapid development of real applications. Herein, we systematically investigate three different treatments, polymer coating, inert atmosphere protection, and thickness-induced self-protection, to protect the tellurium nanowire devices from oxidation when exposed to open air. The degree of oxidation was monitored by examining changes in the valence states of tellurium element and in the morphology of the nanowires~ After the protective treatments, the tellurium nanowire devices showed improved stability and remained stable even after 800 days of storage. This work highlights the importance of investigating the stability of nanowire devices, especially for their practical applications.展开更多
Solid acid catalysts(SACs)have attracted continuous research interest in past years as they play a pivotal role in establishing environmentally friendly and sustainable catalytic processes for various chemical industr...Solid acid catalysts(SACs)have attracted continuous research interest in past years as they play a pivotal role in establishing environmentally friendly and sustainable catalytic processes for various chemical industries.Development of low-cost and efcient SACs applicable to diferent catalysis processes are of immense signifcance but still very challenging so far.Here,we report a new kind of SACs consisting of sulfonated carbon nanofbers that are prepared via incomplete carbonization of low-cost natural nanofbrous cellulose followed by sulphonation with sulfuric acid.Te prepared SACs feature nanofbrous network structures,high specifc surface area,and abundant sulfonate as well as hydroxyl and carboxyl groups.Remarkably,the nanofbrous SACs exhibit superior performance to the state-of-the-art SACs for a wide range of acid-catalyzed reactions,including dimerization of�-methylstyrene,esterifcation of oleic acid,and pinacol rearrangement.Te present approach holds great promise for developing new families of economic but efcient SACs based on natural precursors via scalable and sustainable protocols in the future.展开更多
Material interfaces permit electron transfer that modulates the electronic structure and surface properties of catalysts,leading to radically enhanced rates for many important reactions.Unlike conventional thoughts,th...Material interfaces permit electron transfer that modulates the electronic structure and surface properties of catalysts,leading to radically enhanced rates for many important reactions.Unlike conventional thoughts,the nanoscale interfacial interactions have been recently envisioned to be able to afect the reactivity of catalysts far from the interface.However,demonstration of such unlocalized alterations in existing interfacial materials is rare,impeding the development of new catalysts.We report the observation of unprecedented long-range activation of polydymite Ni_(3)S_(4) nanorods through the interfacial interaction created by PdS_(x) nanodots(dot-on-rod structure)for high-performance water catalytic electroreduction.Experimental results show that this local interaction can activate Ni3S4 rods with length even up to 25 nanometers due to the tailored surface electronic structure.We anticipate that the long-range efect described here may be also applicable to other interfacial material systems,which will aid the development of newly advanced catalysts for modern energy devices.展开更多
Forming alloys with transition metal remarkably decreases the u sage of noble metal and offers benefits for electrocatalysis. Here we introduced a mixed-solvent strategy to synthesize unique Pt Au Cu ternary nanotubes...Forming alloys with transition metal remarkably decreases the u sage of noble metal and offers benefits for electrocatalysis. Here we introduced a mixed-solvent strategy to synthesize unique Pt Au Cu ternary nanotubes(NTs) with porous and rough surface, using high quality Cu nanowires(NWs) as the partial sacrificial templates. We found that Au plays a key role in the enhancement of e lectrocatalytic performance for both methanol oxidation reaction(MOR) and formic acid oxidation reaction(FAOR). The mass activities of Pt Au Cu NTs after acid leaching for MOR and FAOR reach 1698.8 m A mg-1Ptat 0.9 V and 1170 m A mg-1Pt at 0.65 V, respectively. Such ternary NTs show impressive stability due to the irreversibly adsorption of CO* on the Au surface instead of the active Pt surface and the excellent structure stability. The present method could be extended to prepare other new multi-functional electrocatalysts.展开更多
Although nickel-based catalysts display good catalytic capability and excellent corrosion resistance under alkaline electrolytes for water splitting,it is still imperative to enhance their activity for real device app...Although nickel-based catalysts display good catalytic capability and excellent corrosion resistance under alkaline electrolytes for water splitting,it is still imperative to enhance their activity for real device applications.Herein,we decorated Ni0.85Se hollow nanospheres onto reduced graphene oxide(RGO)through a hydrothermal route,then annealed this composite at different temperatures(400℃,NiSe2-400 and 450℃,NiSe2-450)under argon atmosphere,yielding a kind of NiSe2/RGO composite catalysts.Positron annihilation spectra revealed two types of vacancies formed in this composite catalyst.We found that the NiSe2-400 catalyst with dual Ni-Se vacancies is able to catalyze the oxygen evolution reaction(OER)efficiently,needing a mere 241 mV overpotential at 10 mA·cm−2.In addition,this catalyst exhibits outstanding stability.Computational studies show favorable energy barrier on NiSe2-400,enabling moderate OH−adsorption and O2 desorption,which leads to the enhanced energetics for OER.展开更多
Lightweight yet strong paper with high toughness is desirable especially for impact protection. Herein we demonstrated electrically conductive and mechanically robust paper(AP/PB-GP) made of reduced graphene oxide via...Lightweight yet strong paper with high toughness is desirable especially for impact protection. Herein we demonstrated electrically conductive and mechanically robust paper(AP/PB-GP) made of reduced graphene oxide via interfacial crosslinking with 1-aminopyrene(AP) and 1-pyrenebutyrat(PB) small molecules. The AP/PB-GP with thickness of over ten micrometer delivers a record-high toughness(~69.67 ± 15.3 MJ m^(-3) in average), simultaneously with superior strength(close to 1 GPa), allowing an impressive specific penetration energy absorption(~0.17 MJ kg^(-1)) at high impact velocities when used for ballistic impact protection. Detailed interfacial and structural analysis reveals that the reinforcement is synergistically determined by π-π interaction and H-bonding linkage between adjacent graphene lamellae. Especially, the defective pores within the graphene platelets benefit the favorable adsorption of the pyrene-containing molecules, which imperatively maximizes the interfacial binding, facilitating deflecting crack and plastic deformation under loading. Density functional theory simulation suggests that the coupling between the polar functional groups, e.g., –COOH, at the edges of graphene platelets and –NH_(2) and –COOH of AP/PB are critical to the formation of hydrogen bonding network.展开更多
The shape-controlled silver nanostructures have been widely used for template synthesis of metal nanostructures with desired morphologies and compositions for specific applications by galvanic replacement reaction,whi...The shape-controlled silver nanostructures have been widely used for template synthesis of metal nanostructures with desired morphologies and compositions for specific applications by galvanic replacement reaction,while the silver is sacrificed as oxidized to silver ion and abandoned as by-products.In view of the broad application prospect of the obtained metal nanostructures,the cost and environment problems after the template reactions should be taken into account for the large scale production in the future.To solve this problem,we conceptually demonstrate that the wasted AgCl generated from the template reactions can be easily recycled for the synthesis of valuable Ag nanowires.As representative examples,the average recovery of silver can be about 69.8%-84.6% after the template synthesis of Au/Pt nanostructures.The resynthesized Ag nanowires show uniform size distribution and excellent physical and chemical properties for the fabrication of transparent electrode and template synthesis.展开更多
Photooxidation provides a promising strategy for removing the dominant indoor pollutant of HCHO,while the underlying photooxidation mechanism is still unclear,especially the exact role of H2O molecules.Herein,we utili...Photooxidation provides a promising strategy for removing the dominant indoor pollutant of HCHO,while the underlying photooxidation mechanism is still unclear,especially the exact role of H2O molecules.Herein,we utilize in-situ spectral techniques to unveil the H2O-mediated HCHO photooxidation mechanism.As an example,the synthetic defective Bi2WO6 ultrathin sheets realize high-rate HCHO photooxidation with the assistance of H2O at room temperature.In-situ electron paramagnetic resonance spectroscopy demonstrates the existence of•OH radicals,possibly stemmed from H2O oxidation by the photoexcited holes.Synchrotron-radiation vacuum ultraviolet photoionization mass spectroscopy and H218O isotope-labeling experiment directly evidence the formed•OH radicals as the source of oxygen atoms,trigger HCHO photooxidation to produce CO2,while in-situ Fourier transform infrared spectroscopy discloses the HCOO*radical is the main photooxidation intermediate.Density-functional-theory calculations further reveal the•OH formation process is the rate-limiting step,strongly verifying the critical role of H2O in promoting HCHO photooxidation.This work first clearly uncovers the H2O-mediated HCHO photooxidation mechanism,holding promise for high-efficiency indoor HCHO removal at ambient conditions.展开更多
Efficient initiation and resolution of inflammation are crucial for wound repair.However,with using tissue adhesives for wound repair,patients occasionally suffered from delayed healing process because slow eliminatio...Efficient initiation and resolution of inflammation are crucial for wound repair.However,with using tissue adhesives for wound repair,patients occasionally suffered from delayed healing process because slow elimination of those exogenous adhesives generally leads to chronic inflammation.As the demand for minimal invasive therapy continues to rise,desire for adhesive materials that can effectively reconnect surgical gaps and promote wound regeneration becomes increasingly urgent.Herein,by exploiting the inherent porous structure and performance of adhesion to tissue of mesoporous silica nanoparticles(MSNs),we demonstrate a tissue adhesive that can elicit acute inflammatory response and get eliminated after tissue reformation.With formation of nanocomposites in wound gaps,the injured tissues can get reconnected conveniently.The resultant accelerated healing process verifty that the strategy of exploiting unique properties of nanomaterials can effectively promote inflammation resolution and wound repair.This design strategy will inspire more innovative tissue adhesives for clinical applications.展开更多
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2013GB105001,2013GB105002,2015GB109001)National Natural Science Foundation of China(Nos.11305213,11405201)+1 种基金Technological Development Grant of Hefei Science Center of CAS(No.2014TDG-HSC003)China National Funds for Distinguished Young Scientists(No.51325103)
文摘Surface morphology and deuterium retention in ultrafine-grained tungsten fabricated by equal-channel angular pressing（ECAP） have been examined after exposure to a low energy,high-flux deuterium（D） plasma at fluences of 3×10^24 D/m^2 and 1×10^25 D/m^2 in a temperature range of 100 ℃-150 ℃.The methods used were scanning electron microscopy（SEM） and thermal desorption spectroscopy（TDS）.Sparse and small blisters（0.1 μm） were observed by SEM after D plasma irradiation on every irradiated surface;yet they did not exhibit significant structure or plasma fluence dependence.Larger blisters or protrusions appeared after subsequent TDS heating up to 1000 ℃.The TDS results showed a single D desorption peak at 220℃ for all samples and the D retention increased with increasing numbers of extrusion passes,i.e.,the decrease of grain sizes.The increased D retention in this low temperature range should be attributed to the faster diffusion of D along the larger volume fraction of grain boundaries introduced by ECAP.
基金the National Natural Science Foundation of China (Nos.51732011,21431006,2176113200& 21401183 and 21771168)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No.21521001)+5 种基金Key Research Program of Frontier Sciences,CAS (No.QYZDJ-SSWSLH036)the National Basic Research Program of China (No.2014CB931800)the Users with Excellence and Scientific Research Grant of Hefei Science Center of CAS (No.2015HSC-UE007)the Fundamental Research Funds for the Central Universities (Nos.WK2100000005 and WK2090050043)the Joint Funds from Hefei National Synchrotron Radiation Laboratory (No.UN2018LHJJ)This work was partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication.
文摘In the past two decades,the field of surface-enhanced Raman scattering (SERS) has flourished and many rational strategies have been reported for the successful construction of SERS substrates.However,it still lacks the mass-production and programmability for practical applications with arbitrary configurations,and it is highly desirable to develop SERS substrates with strong signal enhancement,large-scale surface area,easy fabrication and low cost.Herein,we demonstrate a large-area fabrication (1.5 m × 5 m) of low-cost (18.8 dollars per square meter),highly sensitive,flexible and transparent SERS substrate by a simple solution process.The high sensitivity of SERS substrate using 3,3'-diethylthiatricarbocyanine iodide (DTTCI) as probe molecules is strongly dependent on the density and diameter of gold nanoparticles (NPs) on the surface of nylon mesh with the best enhancement factor (EF) of 9.17 × 10^10 and the SERS detection limit of DTTCI molecules is as low as 10-14 M which shows no obvious degradation even after 10,000 cycles of fatigue test,high temperature (above than 160 ℃) and acid-alkali treatment,indicating their excellent stability for the performance in all climates.
基金the National Natural Science Foundation of China(21701162,21761132008 and 51702312)Anhui Provincial Natural Science Foundation(1808085MB27)+2 种基金the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(21521001)the Key Research Program of Frontier Sciences,CAS(QYZDJ-SSW-SLH036)the Users with Excellence and Scientific Research Grant of Hefei Science Center of CAS(2015HSC-UE007)。
文摘Magnesium calcite(Mg-calcite)mesocrystal is widespread in the biominerals with specific functions.Until now,it remains challenging to obtain Mg-calcite mesocrystals without organic additives and the formation mechanism of Mg-calcite mesocrystals in the ocean is not clear yet.We report here the synthesis of corn-like Mg-calcite mesocrystals from pure amorphous calcium carbonate(ACC)via a facile method only by using Ca^(2+)and Mg^(2+).The obtained Mg-calcite is composed of many nanocubes with common crystallographic orientation,which shows very good single crystal feature.In the crystallizing procedure,the ACC nanospheres rapidly agglomerate into Mg-calcite corn-like mesocrystal by oriented attachment(OA)in a certain direction,which belongs to the non-classical nucleation.By this method,the molar ratio of Ca^(2+)and Mg^(2+)plays a vital role in the whole crystallization procedure,which may shed a new light on disclosing the mechanism behind for the effect of seawater in the formation of biological Mg-calcite in nature.
文摘Nanowire devices have attracted considerable attention because of their unique structure and novel properties, and have opened up significant development opportunities. However, not many studies have focused on their stability and durability under practical conditions, which limits the rapid development of real applications. Herein, we systematically investigate three different treatments, polymer coating, inert atmosphere protection, and thickness-induced self-protection, to protect the tellurium nanowire devices from oxidation when exposed to open air. The degree of oxidation was monitored by examining changes in the valence states of tellurium element and in the morphology of the nanowires~ After the protective treatments, the tellurium nanowire devices showed improved stability and remained stable even after 800 days of storage. This work highlights the importance of investigating the stability of nanowire devices, especially for their practical applications.
基金Shu-Hong Yu acknowledges the funding support from the National Natural Science Foundation of China(Grants 21431006,21761132008)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant 21521001)+8 种基金Key Research Program of Frontier Sciences,CAS(Grant QYZDJ-SSW-SLH036)the Users with Excellence and Scientifc Research Grant of Hefei Science Center of CAS(2015HSC-UE007)Hai-Wei Liang is thankful for the support by“the Recruitment Program of Global Experts,”National Natural Science Foundation of China(Grant 21671184)the Fundamental Research Funds for the Central Universities(Grant WK2340000076)Zhen-Yu Wu acknowledges the funding support from the National Postdoctoral Program for Innovative Talents(Grant BX201600142)the China Postdoctoral Science Foundation(Grant 2017M610383)the Fundamental Research Funds for the Central Universities(Grant WK2060190077)the National Natural Science Foundation of China(Grant 21703229)This work was partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication.
文摘Solid acid catalysts(SACs)have attracted continuous research interest in past years as they play a pivotal role in establishing environmentally friendly and sustainable catalytic processes for various chemical industries.Development of low-cost and efcient SACs applicable to diferent catalysis processes are of immense signifcance but still very challenging so far.Here,we report a new kind of SACs consisting of sulfonated carbon nanofbers that are prepared via incomplete carbonization of low-cost natural nanofbrous cellulose followed by sulphonation with sulfuric acid.Te prepared SACs feature nanofbrous network structures,high specifc surface area,and abundant sulfonate as well as hydroxyl and carboxyl groups.Remarkably,the nanofbrous SACs exhibit superior performance to the state-of-the-art SACs for a wide range of acid-catalyzed reactions,including dimerization of�-methylstyrene,esterifcation of oleic acid,and pinacol rearrangement.Te present approach holds great promise for developing new families of economic but efcient SACs based on natural precursors via scalable and sustainable protocols in the future.
基金We acknowledge the funding support from the National Natural Science Foundation of China(Grants 21521001,21431006,21225315,21321002,91645202,51702312,and 51802301)the Users with Excellence and Scientifc Research Grant of Hefei Science Center of CAS(2015HSCUE007)+3 种基金the Key Research Program of Frontier Sciences,CAS(Grant QYZDJ-SSWSLH036)the Chinese Academy of Sciences(Grants KGZDEW-T05,XDA090301001)the Fundamental Research Funds for the Central Universities(WK2060190045,WK2340000076)the Recruitment Program of Global Youth Experts.We would like to thank the beamline 1W1B station in the Beijing Synchrotron Radiation Facility and BL14W1 at the Shanghai Synchrotron Radiation Facility for help with the characterizations.Tis work was partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication.
文摘Material interfaces permit electron transfer that modulates the electronic structure and surface properties of catalysts,leading to radically enhanced rates for many important reactions.Unlike conventional thoughts,the nanoscale interfacial interactions have been recently envisioned to be able to afect the reactivity of catalysts far from the interface.However,demonstration of such unlocalized alterations in existing interfacial materials is rare,impeding the development of new catalysts.We report the observation of unprecedented long-range activation of polydymite Ni_(3)S_(4) nanorods through the interfacial interaction created by PdS_(x) nanodots(dot-on-rod structure)for high-performance water catalytic electroreduction.Experimental results show that this local interaction can activate Ni3S4 rods with length even up to 25 nanometers due to the tailored surface electronic structure.We anticipate that the long-range efect described here may be also applicable to other interfacial material systems,which will aid the development of newly advanced catalysts for modern energy devices.
基金supported by the National Natural Science Foundation of China(21431006)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(21521001)+2 种基金the National Basic Research Program of China(2014CB931800 and 2013CB931800)the Users with Excellence and Scientific Research Grant of Hefei Science Center of CAS(2015HSCUE007 and 2015SRG-HSC038)the Chinese Academy of Sciences(KJZD-EW-M01-1)
文摘Forming alloys with transition metal remarkably decreases the u sage of noble metal and offers benefits for electrocatalysis. Here we introduced a mixed-solvent strategy to synthesize unique Pt Au Cu ternary nanotubes(NTs) with porous and rough surface, using high quality Cu nanowires(NWs) as the partial sacrificial templates. We found that Au plays a key role in the enhancement of e lectrocatalytic performance for both methanol oxidation reaction(MOR) and formic acid oxidation reaction(FAOR). The mass activities of Pt Au Cu NTs after acid leaching for MOR and FAOR reach 1698.8 m A mg-1Ptat 0.9 V and 1170 m A mg-1Pt at 0.65 V, respectively. Such ternary NTs show impressive stability due to the irreversibly adsorption of CO* on the Au surface instead of the active Pt surface and the excellent structure stability. The present method could be extended to prepare other new multi-functional electrocatalysts.
基金We acknowledge financial support from the Tianjin science and technology support key projects(No.18YFZCSF00500)the National Natural Science Foundation of China(Nos.21521001,21431006,21225315,21321002,91645202,51702312,and 21975237)+6 种基金the Users with Excellence and Scientific Research Grant of Hefei Science Center of CAS(No.2015HSCUE007)the Key Research Program of Frontier Sciences,CAS(No.QYZDJ-SSW-SLH036)the National Basic Research Program of China(Nos.2014CB931800 and 2018YFA0702001)the Chinese Academy of Sciences(Nos.KGZD-EW-T05 and XDA090301001)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA21000000)the Fundamental Research Funds for the Central Universities(No.WK2340000076)the Recruitment Program of Global Youth Experts.
文摘Although nickel-based catalysts display good catalytic capability and excellent corrosion resistance under alkaline electrolytes for water splitting,it is still imperative to enhance their activity for real device applications.Herein,we decorated Ni0.85Se hollow nanospheres onto reduced graphene oxide(RGO)through a hydrothermal route,then annealed this composite at different temperatures(400℃,NiSe2-400 and 450℃,NiSe2-450)under argon atmosphere,yielding a kind of NiSe2/RGO composite catalysts.Positron annihilation spectra revealed two types of vacancies formed in this composite catalyst.We found that the NiSe2-400 catalyst with dual Ni-Se vacancies is able to catalyze the oxygen evolution reaction(OER)efficiently,needing a mere 241 mV overpotential at 10 mA·cm−2.In addition,this catalyst exhibits outstanding stability.Computational studies show favorable energy barrier on NiSe2-400,enabling moderate OH−adsorption and O2 desorption,which leads to the enhanced energetics for OER.
基金supported by the National Natural Science Foundation of China (51772282,51972299)funding from Hefei Center for Physical Science and Technology。
文摘Lightweight yet strong paper with high toughness is desirable especially for impact protection. Herein we demonstrated electrically conductive and mechanically robust paper(AP/PB-GP) made of reduced graphene oxide via interfacial crosslinking with 1-aminopyrene(AP) and 1-pyrenebutyrat(PB) small molecules. The AP/PB-GP with thickness of over ten micrometer delivers a record-high toughness(~69.67 ± 15.3 MJ m^(-3) in average), simultaneously with superior strength(close to 1 GPa), allowing an impressive specific penetration energy absorption(~0.17 MJ kg^(-1)) at high impact velocities when used for ballistic impact protection. Detailed interfacial and structural analysis reveals that the reinforcement is synergistically determined by π-π interaction and H-bonding linkage between adjacent graphene lamellae. Especially, the defective pores within the graphene platelets benefit the favorable adsorption of the pyrene-containing molecules, which imperatively maximizes the interfacial binding, facilitating deflecting crack and plastic deformation under loading. Density functional theory simulation suggests that the coupling between the polar functional groups, e.g., –COOH, at the edges of graphene platelets and –NH_(2) and –COOH of AP/PB are critical to the formation of hydrogen bonding network.
基金supported by the National Natural Science Foundation of China(21431006)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(21521001)+2 种基金the National Basic Research Program of China(2014CB931800 and 2013CB931800)the Users with Excellence and Scientific Research Grant of Hefei Science Center of Chinese Academy of Sciences(CAS)(2015HSC-UE007 and 2015SRG-HSC038)the CAS(KJZD-EW-M01-1)
文摘The shape-controlled silver nanostructures have been widely used for template synthesis of metal nanostructures with desired morphologies and compositions for specific applications by galvanic replacement reaction,while the silver is sacrificed as oxidized to silver ion and abandoned as by-products.In view of the broad application prospect of the obtained metal nanostructures,the cost and environment problems after the template reactions should be taken into account for the large scale production in the future.To solve this problem,we conceptually demonstrate that the wasted AgCl generated from the template reactions can be easily recycled for the synthesis of valuable Ag nanowires.As representative examples,the average recovery of silver can be about 69.8%-84.6% after the template synthesis of Au/Pt nanostructures.The resynthesized Ag nanowires show uniform size distribution and excellent physical and chemical properties for the fabrication of transparent electrode and template synthesis.
基金This work was financially supported by National Key R&D Program of China(Nos.2019YFA0210004 and 2017YFA0207301)the National Natural Science Foundation of China(Nos.21975242 and 21890754)+5 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36000000)Youth Innovation Promotion Association of CAS(No.CX2340007003)Major Program of Development Foundation of Hefei Center for Physical Science and Technology(No.2020HSC-CIP003)Key Research Program of Frontier Sciences of CAS(No.QYZDYSSW-SLH011)the Fok Ying-Tong Education Foundation(No.161012)Supercomputing USTC and National Supercomputing Center in Shenzhen are acknowledged for computational support.
文摘Photooxidation provides a promising strategy for removing the dominant indoor pollutant of HCHO,while the underlying photooxidation mechanism is still unclear,especially the exact role of H2O molecules.Herein,we utilize in-situ spectral techniques to unveil the H2O-mediated HCHO photooxidation mechanism.As an example,the synthetic defective Bi2WO6 ultrathin sheets realize high-rate HCHO photooxidation with the assistance of H2O at room temperature.In-situ electron paramagnetic resonance spectroscopy demonstrates the existence of•OH radicals,possibly stemmed from H2O oxidation by the photoexcited holes.Synchrotron-radiation vacuum ultraviolet photoionization mass spectroscopy and H218O isotope-labeling experiment directly evidence the formed•OH radicals as the source of oxygen atoms,trigger HCHO photooxidation to produce CO2,while in-situ Fourier transform infrared spectroscopy discloses the HCOO*radical is the main photooxidation intermediate.Density-functional-theory calculations further reveal the•OH formation process is the rate-limiting step,strongly verifying the critical role of H2O in promoting HCHO photooxidation.This work first clearly uncovers the H2O-mediated HCHO photooxidation mechanism,holding promise for high-efficiency indoor HCHO removal at ambient conditions.
基金This work was supported by the National Natural Science Foundation of China(Nos.51732011,21431006,21761132008,51471157,21401183,and 21771168)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.21521001)+3 种基金Key Research Program of Frontier Sciences,CAS(No.QYZDJ-SSW-SLH036)the National Basic Research Program of China(No.2014CB931800)the Users with Excellence and Scientific Research Grant of Hefei Science Center of CAS(No.2015HSC-UE007)the Youth Innovation Promotion Association of CAS(No.2014298).
文摘Efficient initiation and resolution of inflammation are crucial for wound repair.However,with using tissue adhesives for wound repair,patients occasionally suffered from delayed healing process because slow elimination of those exogenous adhesives generally leads to chronic inflammation.As the demand for minimal invasive therapy continues to rise,desire for adhesive materials that can effectively reconnect surgical gaps and promote wound regeneration becomes increasingly urgent.Herein,by exploiting the inherent porous structure and performance of adhesion to tissue of mesoporous silica nanoparticles(MSNs),we demonstrate a tissue adhesive that can elicit acute inflammatory response and get eliminated after tissue reformation.With formation of nanocomposites in wound gaps,the injured tissues can get reconnected conveniently.The resultant accelerated healing process verifty that the strategy of exploiting unique properties of nanomaterials can effectively promote inflammation resolution and wound repair.This design strategy will inspire more innovative tissue adhesives for clinical applications.
