Synthesizing atomically precise Ag nanoclusters(NCs),which is essential for the general development of NCs,is quite challenging.In this study,we report the synthesis of high-purity atomically precise Ag NCs via a kine...Synthesizing atomically precise Ag nanoclusters(NCs),which is essential for the general development of NCs,is quite challenging.In this study,we report the synthesis of high-purity atomically precise Ag NCs via a kinetically controlled strategy.The Ag NCs were prepared using a mild reducing agent via a one-pot method.The as-prepared Ag NCs were confirmed to be Ag_(49)(D-pen)_(24)(D-pen:D-penicillamine)on the basis of their matrix-assisted laser desorption ionization time-of-flight mass spectrometric and thermogravimetric characteristics.The interfacial structures of the Ag NCs were illustrated by proton nuclear magnetic resonance and Fourier-transform infrared spectroscopy.The Ag NCs were supported on activated carbon(AC)to form Ag NCs/AC,which displayed excellent activity for the catalytic reduction of 4-nitrophenol with a kinetic reaction rate constant k of 0.21 min^(-1).Such a high k value indicates that the composite could outperform several previously reported catalysts.Moreover,the catalytic activity of Ag NCs/AC remained nearly constant after six times of recycle,which suggests its excellent stability.展开更多
The unique crystal structure and multiple redox couples of iron titanate(Fe_(2)TiO_(5)) provide it a high theoretical capacity and good cycling stability when used as an electrode. In this study, the electrospinning m...The unique crystal structure and multiple redox couples of iron titanate(Fe_(2)TiO_(5)) provide it a high theoretical capacity and good cycling stability when used as an electrode. In this study, the electrospinning method is employed to synthesize one-dimensional(1 D) Fe_(2)TiO_(5) nanochains. The as-prepared Fe_(2)TiO_(5) nanochains exhibited superior specific capacity(500 mAh·g^(-1) at 0.10 A·g^(-1)),excellent rate performance(180 mAh·g^(-1) at 5.00 A·g^(-1)),and good cycling stability(retaining 100% of the initial specific capacity at a current density of 1.00 A·g^(-1) after1000 cycles). The as-assembled Fe_(2)TiO_(5)/SCCB lithiumion capacitor(LIC) also delivered a competitive energy density(137.8 Wh·kg^(-1))andpowerdensity(11,250 W·kg^(-1)). This study proves that the as-fabricated1 D Fe_(2)TiO_(5) nanochains are promising anode materials for high-performance LICs.展开更多
Many electrochemical energy storage devices,such as batteries,supercapacitors,and metal ion capacitors,rely on effective and inexpensive electrode materials.Herein,we have developed highly active nitrogen-doped porous...Many electrochemical energy storage devices,such as batteries,supercapacitors,and metal ion capacitors,rely on effective and inexpensive electrode materials.Herein,we have developed highly active nitrogen-doped porous carbon nanofoams(NPCNs-600-N)for sodium-ion capacitors(SICs).NPCNs-600-N have a highly porous framework,extended interlayer spacing(0.41 nm),and lots of surface functional groups.Accordingly,NPCNs-600-N achieves a high reversible capacity(301 mAh·g^(-1)at 0.05 A·g^(-1)),superior rate capability(112 mAh·g^(-1)at 5.00 A·g^(-1)),and ultra-stable cyclability.The excellent rate and cycling performance originate from the abundant active sites and porous architecture of NPCNs-600-N.Further-more,SICs device is constructed by employing the NPCNs-600-N as the battery-like anode and commercial superconductive carbon black as the capacitive cathode,which delivers high energy/power densities of 92 Wh·kg^(-1)/15984 W·kg^(-1)with a remarkable cyclability(93%reten-tion over 5000 cycles at 1.00 A·g^(-1)).The methodology of the work enables the simultaneous tuning of the porous architectures and surface function groups of carbon for high-performance SICs.展开更多
Mesoporous silica(mSiO_(2))has attracted great interest as anode for lithium-ion batteries.However,the low intrinsic conductivity is a major challenge for its commercialization.In this study,a low-cost sol–gel method...Mesoporous silica(mSiO_(2))has attracted great interest as anode for lithium-ion batteries.However,the low intrinsic conductivity is a major challenge for its commercialization.In this study,a low-cost sol–gel method is employed to synthesize mesoporous silica anchored on graphene nanosheets(rGO)for lithium storage.The results exhibit that the nanocomposite(mSiO_(2)@rGO)with high surface area(616.45 m^(2)·g^(–1))has chemical coupling bonds(Si–O–C)between SiO2 and rGO species,which would be favorable for lithium storage upon synergistic effects.Consequently,the mSiO_(2)@rGO exhibits a high specific capacity of 1119.6 mAh·g^(–1)at 0.1 A·g^(–1)with outstanding cycling stability(92.5%retention over 1400 cycles at 1.0 A·g^(–1)).展开更多
Here we show a study of vibrational spectroscopic identification of a few typical organic compounds which are known as the main sources of organic aerosols（OAs） particle matter in air pollution. Raman and IR spectra...Here we show a study of vibrational spectroscopic identification of a few typical organic compounds which are known as the main sources of organic aerosols（OAs） particle matter in air pollution. Raman and IR spectra of isoprene, terpenoids, pinenes and their mixture are meticulously examined, showing distinguishable intrinsic vibrational spectroscopic fingerprints for these chemicals, respectively. As a reference, first-principles calculations of Raman and infrared activities are also conducted. It is interestingly found that, the experimental spectra are peak-to-peak consistent with the DFT（Density Functional Theory）-calculated vibrational activities. Also found is that, in a certain case such as for bpinene, a dimer model, rather than an isolated single molecular model, reproduces the experimental results, indicating unneglected intermolecular interactions. Starting with this study, we are endeavoring to advocate a database of Raman/IR fingerprint spectra for OA haze identification.展开更多
Herein,isotactic polypropylene films with smallβ-nucleating agent content were fabricated via a melt-extrusion-stretched technology with intended"shear-free"in barrel and die.Compared with neat films,the te...Herein,isotactic polypropylene films with smallβ-nucleating agent content were fabricated via a melt-extrusion-stretched technology with intended"shear-free"in barrel and die.Compared with neat films,the tensile strength,elongation at break and strain energy density at break of i PP film with 0.05 wt%β-nucleating agent are significantly improved by 13.8%,39.6%and 90.6%,respectively,indicating the simultaneously enhanced toughness and strength.Additionally,theβ-crystal content gradually increases with increasingβ-NA content,while the relative total daughter content ofα-andβ-crystal exhibits opposite tendency.Moreover,nucleation and crystal growth induced by variousβ-NA contents are different.This work proves an efficient strategy to enhance mechanical properties of isotactic polypropylene film via controlling elongation flow and addition of appropriateβ-NA content.展开更多
All-solid-state batteries(ASSBs) hold great promise for next-generation energy storage technologies owing to their advantage in different aspects such as energy density,safety,and wide temperature tolerance.However,th...All-solid-state batteries(ASSBs) hold great promise for next-generation energy storage technologies owing to their advantage in different aspects such as energy density,safety,and wide temperature tolerance.However,the use of solid-state electrolytes(SSEs) instead of liquid ones meanwhile brings serious concerns related to the point-to-point contact between SSEs and electrodes,which is known to result in high interface resistance and inhomogeneous distribution of charges during the Li^(+)plating/stripping process,eventually leading to a premature failure of ASSBs.This review focuses on the garnet-type SSEs in the formula of Li_(7)La_(3)Zr_(2)O_(12)(LLZO),and discusses the structure-performance relationship of this ceramic electrolyte in detail to achieve a clear understanding of its Li^(+)transmission mechanism.Meanwhile,the challenges of cubic phase LLZO(c-LLZO) for their application in solidstate batteries(SSBs) are demonstrated by the Li/LLZO interface,which features the importance of Li metal wettability and dendrite suppression for sustainable performance.Furthermore,this review summarizes the recent research strategies to combat these contact issues at the Li/LLZO interface,highlighting the essential role played by surface modification of LLZO electrolytes.Following the obtained insights,perspectives for future research on LLZO to accelerate its potential development of SSBs in commercialized applications are also provided.展开更多
基金financially supported by the Huaibei Normal University Doctoral Research Start-up Funding(No.15601012)the Natural Science Foundation of Anhui Provincial Department of Education(No.KJ2019A0598)+1 种基金the Excellent Young Talents Fund Program of Higher Education Institutions of Anhui Province,China(No.gxyq2019168)the Team of Superior Discipline of Chemistry(No.GFXK202108).
文摘Synthesizing atomically precise Ag nanoclusters(NCs),which is essential for the general development of NCs,is quite challenging.In this study,we report the synthesis of high-purity atomically precise Ag NCs via a kinetically controlled strategy.The Ag NCs were prepared using a mild reducing agent via a one-pot method.The as-prepared Ag NCs were confirmed to be Ag_(49)(D-pen)_(24)(D-pen:D-penicillamine)on the basis of their matrix-assisted laser desorption ionization time-of-flight mass spectrometric and thermogravimetric characteristics.The interfacial structures of the Ag NCs were illustrated by proton nuclear magnetic resonance and Fourier-transform infrared spectroscopy.The Ag NCs were supported on activated carbon(AC)to form Ag NCs/AC,which displayed excellent activity for the catalytic reduction of 4-nitrophenol with a kinetic reaction rate constant k of 0.21 min^(-1).Such a high k value indicates that the composite could outperform several previously reported catalysts.Moreover,the catalytic activity of Ag NCs/AC remained nearly constant after six times of recycle,which suggests its excellent stability.
基金financially supported by the Natural Science Foundation of Jiangsu Province(No.BK20170549)the National Natural Science Foundation of China(No.21706103)+1 种基金the China Postdoctoral Science Foundation(No.2019T120393)the Postdoctoral Science Foundation of Jiangsu Province(No.2019K295)。
文摘The unique crystal structure and multiple redox couples of iron titanate(Fe_(2)TiO_(5)) provide it a high theoretical capacity and good cycling stability when used as an electrode. In this study, the electrospinning method is employed to synthesize one-dimensional(1 D) Fe_(2)TiO_(5) nanochains. The as-prepared Fe_(2)TiO_(5) nanochains exhibited superior specific capacity(500 mAh·g^(-1) at 0.10 A·g^(-1)),excellent rate performance(180 mAh·g^(-1) at 5.00 A·g^(-1)),and good cycling stability(retaining 100% of the initial specific capacity at a current density of 1.00 A·g^(-1) after1000 cycles). The as-assembled Fe_(2)TiO_(5)/SCCB lithiumion capacitor(LIC) also delivered a competitive energy density(137.8 Wh·kg^(-1))andpowerdensity(11,250 W·kg^(-1)). This study proves that the as-fabricated1 D Fe_(2)TiO_(5) nanochains are promising anode materials for high-performance LICs.
基金financially supported by the Natural Science Foundation of Jiangsu Province (No. BK20170549)the National Natural Science Foundation of China (Nos. 21706103 and 22075109)+2 种基金Nanjing Tech University Research Start-Up Fund (No. 38274017111)Zhongyan Jilantai Chlor-Alkali Chemical Co., Ltd (No. FZ2019-RWS-027)the Open Fund of the Key Laboratory of Fine Chemical Application Technology of Luzhou (No. HYJH-2101-B)
文摘Many electrochemical energy storage devices,such as batteries,supercapacitors,and metal ion capacitors,rely on effective and inexpensive electrode materials.Herein,we have developed highly active nitrogen-doped porous carbon nanofoams(NPCNs-600-N)for sodium-ion capacitors(SICs).NPCNs-600-N have a highly porous framework,extended interlayer spacing(0.41 nm),and lots of surface functional groups.Accordingly,NPCNs-600-N achieves a high reversible capacity(301 mAh·g^(-1)at 0.05 A·g^(-1)),superior rate capability(112 mAh·g^(-1)at 5.00 A·g^(-1)),and ultra-stable cyclability.The excellent rate and cycling performance originate from the abundant active sites and porous architecture of NPCNs-600-N.Further-more,SICs device is constructed by employing the NPCNs-600-N as the battery-like anode and commercial superconductive carbon black as the capacitive cathode,which delivers high energy/power densities of 92 Wh·kg^(-1)/15984 W·kg^(-1)with a remarkable cyclability(93%reten-tion over 5000 cycles at 1.00 A·g^(-1)).The methodology of the work enables the simultaneous tuning of the porous architectures and surface function groups of carbon for high-performance SICs.
基金This study was financially supported by the Postdoctoral Science Foundation of Jiangsu Province(No.2019K295)the Six Talent Peaks Project in Jiangsu Province(No.XNY-007,2018)+3 种基金the“333”Project in Jiangsu Province(No.BRA2019277)the Natural Science Foundation of Jiangsu Province(No.BK20170549)and the National Natural Science Foundation of China(Nos.21706103 and 22075109)Sherif A.El-Khodary would like to thank Jiangsu University for supporting the post-doctoral fellowship and funding the current project.
文摘Mesoporous silica(mSiO_(2))has attracted great interest as anode for lithium-ion batteries.However,the low intrinsic conductivity is a major challenge for its commercialization.In this study,a low-cost sol–gel method is employed to synthesize mesoporous silica anchored on graphene nanosheets(rGO)for lithium storage.The results exhibit that the nanocomposite(mSiO_(2)@rGO)with high surface area(616.45 m^(2)·g^(–1))has chemical coupling bonds(Si–O–C)between SiO2 and rGO species,which would be favorable for lithium storage upon synergistic effects.Consequently,the mSiO_(2)@rGO exhibits a high specific capacity of 1119.6 mAh·g^(–1)at 0.1 A·g^(–1)with outstanding cycling stability(92.5%retention over 1400 cycles at 1.0 A·g^(–1)).
基金supported by Young Professionals Program in Institute of Chemistry,Chinese Academy of Sciences (No. Y3297B1261)financial support from CAS project (Nos. Y31M0112C1 and Y5294512C1)
文摘Here we show a study of vibrational spectroscopic identification of a few typical organic compounds which are known as the main sources of organic aerosols（OAs） particle matter in air pollution. Raman and IR spectra of isoprene, terpenoids, pinenes and their mixture are meticulously examined, showing distinguishable intrinsic vibrational spectroscopic fingerprints for these chemicals, respectively. As a reference, first-principles calculations of Raman and infrared activities are also conducted. It is interestingly found that, the experimental spectra are peak-to-peak consistent with the DFT（Density Functional Theory）-calculated vibrational activities. Also found is that, in a certain case such as for bpinene, a dimer model, rather than an isolated single molecular model, reproduces the experimental results, indicating unneglected intermolecular interactions. Starting with this study, we are endeavoring to advocate a database of Raman/IR fingerprint spectra for OA haze identification.
基金financially supported by the National Natural Science Foundation of China(Nos.11432003 and 11572290)Young Teacher Project of Zhongyuan University of Technology(No.2019XQG05)。
文摘Herein,isotactic polypropylene films with smallβ-nucleating agent content were fabricated via a melt-extrusion-stretched technology with intended"shear-free"in barrel and die.Compared with neat films,the tensile strength,elongation at break and strain energy density at break of i PP film with 0.05 wt%β-nucleating agent are significantly improved by 13.8%,39.6%and 90.6%,respectively,indicating the simultaneously enhanced toughness and strength.Additionally,theβ-crystal content gradually increases with increasingβ-NA content,while the relative total daughter content ofα-andβ-crystal exhibits opposite tendency.Moreover,nucleation and crystal growth induced by variousβ-NA contents are different.This work proves an efficient strategy to enhance mechanical properties of isotactic polypropylene film via controlling elongation flow and addition of appropriateβ-NA content.
基金financially supported by the National Natural Science Foundation of China (Nos. 22025507 and 21931012)the Key Research Program of Frontier Sciences, CAS (No. ZDBS-LY-SLH020)Beijing National Laboratory for Molecular Sciences (No. BNLMS-CXXM-202010)。
文摘All-solid-state batteries(ASSBs) hold great promise for next-generation energy storage technologies owing to their advantage in different aspects such as energy density,safety,and wide temperature tolerance.However,the use of solid-state electrolytes(SSEs) instead of liquid ones meanwhile brings serious concerns related to the point-to-point contact between SSEs and electrodes,which is known to result in high interface resistance and inhomogeneous distribution of charges during the Li^(+)plating/stripping process,eventually leading to a premature failure of ASSBs.This review focuses on the garnet-type SSEs in the formula of Li_(7)La_(3)Zr_(2)O_(12)(LLZO),and discusses the structure-performance relationship of this ceramic electrolyte in detail to achieve a clear understanding of its Li^(+)transmission mechanism.Meanwhile,the challenges of cubic phase LLZO(c-LLZO) for their application in solidstate batteries(SSBs) are demonstrated by the Li/LLZO interface,which features the importance of Li metal wettability and dendrite suppression for sustainable performance.Furthermore,this review summarizes the recent research strategies to combat these contact issues at the Li/LLZO interface,highlighting the essential role played by surface modification of LLZO electrolytes.Following the obtained insights,perspectives for future research on LLZO to accelerate its potential development of SSBs in commercialized applications are also provided.
