Biomass, as the most widely used carbon sources, is the main ingredient in the formation of fossil fuels. Biomass-derived novel carbons(BDNCs) have attracted much attention because of its adjustable physical/chemical ...Biomass, as the most widely used carbon sources, is the main ingredient in the formation of fossil fuels. Biomass-derived novel carbons(BDNCs) have attracted much attention because of its adjustable physical/chemical properties, environmentally friendliness, and considerable economic value. Nature contributes to the biomass with bizarre microstructures with micropores, mesopores or hierarchical pores.Currently, it has been confirmed that biomass has great potential applications in energy storage devices,especially in lithium-sulfur(Li–S) batteries. In this article, the synthesis and function of BDNCs for Li–S batteries are presented, and the electrochemical effects of structural diversity, porosity and surface heteroatom doping of the carbons in Li-S batteries are discussed. In addition, the economic benefits, new trends and challenges are also proposed for further design excellent BDNCs for Li–S batteries.展开更多
Two electron-rich, solution-processable phenonaphthazine derivatives, 5,12-bis(N-[4,4'-bis-(phenyl) aminophen-4 ''-yl]}-phenonaphthazine (BPZTPA) and 5,12-bis{N-[4,4'-bis(methoxy-phenyl)aminophen-4'...Two electron-rich, solution-processable phenonaphthazine derivatives, 5,12-bis(N-[4,4'-bis-(phenyl) aminophen-4 ''-yl]}-phenonaphthazine (BPZTPA) and 5,12-bis{N-[4,4'-bis(methoxy-phenyl)aminophen-4'-phenonaphthazine (MeO-BPZTPA) have been designed and employed in the fabrication of perovskite solar cells. BPZTPA and MeO-BPZTPA exhibit excellent thermal stabilities, hole mobilities (similar to 10(-4) cm(2)/(V.s)) and suitable HOMO levels (-5.34 and-5.29 eV, respectively) relative to the valence band of the CH3NH3PbI3 and Au work function, showing their potential as alternative hole-transporting materials (HTMs). Meanwhile, the corresponding mesoporous TiO2/CH3NH3PbI3/HTM/Au devices are investigated, and the best power conversion efficiency of 10.36% has been achieved for MeO-BPZTPA without using p-type dopant. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
we have synthesised a series of new optically nonlinear organic materials of cinnamylidene-acetophenone derivatives which have large nonl inear optical susceptibilities and short cut-off wavelengths.
A series of star-shaped molecules with benzene core and naphthalimides derivatives end groups have been designed to explore their optical,electronic,and charge transport properties as charge transport and/or luminesce...A series of star-shaped molecules with benzene core and naphthalimides derivatives end groups have been designed to explore their optical,electronic,and charge transport properties as charge transport and/or luminescent materials for organic light-emitting diodes（OLEDs）. The frontier molecular orbitals（FMOs） analysis has turned out that the vertical electronic transitions of absorption and emission are characterized as intramolecular charge transfer（ICT）. The calculated results show that the optical and electronic properties of star-shaped molecules are affected by the substituent groups in N-position of 1,8-naphthalimide ring. Our results suggest that star-shaped molecules with n-butyl（1）,benzene（2）,thiophene（3）,thiophene S？,S？-dioxide（4）,benzo[c][1,2,5]thiadiazole（5）,and 2,7a-dihydrobenzo[d]thiazole（6） fragments are expected to be promising candidates for luminescent and electron transport materials for OLEDs. This study should be helpful in further theoretical investigations on such kind of systems and also to the experimental study for charge transport and/or luminescent materials for OLEDs.展开更多
Lithium-sulfur(Li-S) battery is a potential energy storage technology with high energy density and low cost. However, the gap between theoretical expectation and practical performance limits its wide implementation. H...Lithium-sulfur(Li-S) battery is a potential energy storage technology with high energy density and low cost. However, the gap between theoretical expectation and practical performance limits its wide implementation. Herein, we report a nitrogen-doped porous carbon derived from biomass pomelo peel as sulfur host material for Li-S batteries. The hierarchical porous architecture and the polar surface introduced by N-doping render a favorable combination of physical and chemical sulfur confinements as well as an expedite electron/ion transfer, thus contributing to a facilitated and stabilized sulfur electrochemistry. As a result, the corresponding sulfur composite electrodes exhibit an ultrahigh initial capacity of 1534.6 mAh g^-1, high coulombic efficiency over 98% upon 300 cycles, and decent rate capability up to 2 C. This work provides an economical and effective strategy for the fabrication of advanced carbonaceous sulfur host material as well as the significant improvement of Li-S battery performance.展开更多
At present,two-dimensional(2D)materials have shown great application potential in numerous fields based on their physical chemical and electronic properties.Raman spectroscopy and de-rivative techniques are effective ...At present,two-dimensional(2D)materials have shown great application potential in numerous fields based on their physical chemical and electronic properties.Raman spectroscopy and de-rivative techniques are effective tools for characterizing 2D materials.Raman spectroscopy conveys lots of knowledge on 2D materials,including layer number,doping type,strain and interlayer coupling.This review summarized advanced applications of Raman spectroscopy in 2D materials.The challenges and possible applied directions of Raman spectroscopy to 2D materials are discussed in detail.展开更多
Biomass-derived carbon materials have aroused widespread concern as host material of sulfur to enhance electrochemical performances for lithium–sulfur batteries. Herein, goat hair, as a low-cost and eco-friendly prec...Biomass-derived carbon materials have aroused widespread concern as host material of sulfur to enhance electrochemical performances for lithium–sulfur batteries. Herein, goat hair, as a low-cost and eco-friendly precursor, is employed to fabricate cauliflower-like in-situ nitrogen, oxygen and phosphorus tri-doped porous biomass carbon(NOPC) by a facile activation with H_3PO_4 and carbonization process.The morphology and microstructure of NOPC can be readily tuned by altering pyrolysis temperature. The as-prepared NOPC matrix material carbonized at 600 °C possesses 3D hierarchical porous structure, high specific surface area(535.352 m^2 g^(-1)), and appropriate pore size and pore size distribution. Encapsulating sulfur into the NOPC depends on a stem-melting technology as cathode materials of Li–S batteries. Due to the synergistic effect of special physical structure and inherent tri-doping of N, O and P, electrons and ions transfer and utilization of active sulfur in the materials are improved, and the shuttle behaviors of soluble lithium polysulfides are also mitigated. Consequently, the S/NOPC-600 composite exhibits excellent electrochemical performance, giving a high initial discharge capacity of 1185 mA h g^(-1) at 0.05 C and maintaining a relatively considerable capacity of 489 m A h g^(-1) at 0.2 C after 300 cycles. Our work shows that a promising candidate for cathode material of Li–S batteries can be synthesized using low-cost and renewable biomass materials by a facile process.展开更多
Based on synthesizing pure spinel type lithium manganese oxides,the derivations such as LiMn1.5Ti0.5-O4,LiMn1.5Fe0.5O4,LiMn1 .5Ni0.5O4 and LiMn1.5Zn0.5O4 were prepared using solid- step-sintering method. The structure...Based on synthesizing pure spinel type lithium manganese oxides,the derivations such as LiMn1.5Ti0.5-O4,LiMn1.5Fe0.5O4,LiMn1 .5Ni0.5O4 and LiMn1.5Zn0.5O4 were prepared using solid- step-sintering method. The structures were characterized by using XRD,SEM and laser granulometer. The electrochemical measurement results show that the elemen t of iron or nickel can raise the discharging plateau voltage of LiMn2O4,an d element titanium improves the electrochemistry property of LiMn2O4 little,while element zinc destroys the electrochemistry property of LiMn2O4. The i nfluence of elements of titanium,iron,nickel,or zinc on the structure of LiMn 2O4 pure phase was discussed from the viewpoint of structural chemistry.展开更多
In the paper the elasticity tensor and the relation between stress and strain of transverse isotropic material and isotropic material are deduced by tensor derivate. From the derivation the reason why there are two in...In the paper the elasticity tensor and the relation between stress and strain of transverse isotropic material and isotropic material are deduced by tensor derivate. From the derivation the reason why there are two independent elasticity coefficients for isotropic elastic material and five for transverse isotropic elastic material can be seen more clearly.展开更多
In order to formulate a general expression of elastic tensor for anisotropic materials, a method of tensor derivative is used for determining relationship between fourth-order elastic tensor and second-order structure...In order to formulate a general expression of elastic tensor for anisotropic materials, a method of tensor derivative is used for determining relationship between fourth-order elastic tensor and second-order structure tensor that has satisfied material symmetrical conditions. From this general expression of elastic tensor, specific expressions of elastic tensor for different anisotropic materials, such as isotropic materials, transverse isotropic materials and orthogonal-anisotropic materials, can be deduced. This expression underlies the scalar description of anisotropic factors, which are used for classifying and analyzing anisotropic materials. Cubic crystals are analyzed macroscopically by means of the general expression and anisotropic factor.展开更多
基金supported by the National Natural Science Foundation of China (U1832136 and 21303038)Think-Tank Union Funds for Energy Storage (Grant No.JZ2016QTXM1097)+3 种基金Open Funds of the State Key Laboratory of Rare Earth Resource Utilization (Grant No. RERU2016004)the Fundamental Research Funds for the Central Universities (JZ2016HGTA0690)Natural Science Foundation of Anhui province (1808085QE140)100 Talents Plan of Anhui
文摘Biomass, as the most widely used carbon sources, is the main ingredient in the formation of fossil fuels. Biomass-derived novel carbons(BDNCs) have attracted much attention because of its adjustable physical/chemical properties, environmentally friendliness, and considerable economic value. Nature contributes to the biomass with bizarre microstructures with micropores, mesopores or hierarchical pores.Currently, it has been confirmed that biomass has great potential applications in energy storage devices,especially in lithium-sulfur(Li–S) batteries. In this article, the synthesis and function of BDNCs for Li–S batteries are presented, and the electrochemical effects of structural diversity, porosity and surface heteroatom doping of the carbons in Li-S batteries are discussed. In addition, the economic benefits, new trends and challenges are also proposed for further design excellent BDNCs for Li–S batteries.
基金the financial support from National High-tech R&D Program(863 Program)(2015AA033402)the Science and Technology Planning Project of Tianjin Province,China(No.14TXGCCX00017)+1 种基金Tianjin science and technology plan projects(13ZCZDGX00900)the National Natural Science Foundation of China(No.11474333)
文摘Two electron-rich, solution-processable phenonaphthazine derivatives, 5,12-bis(N-[4,4'-bis-(phenyl) aminophen-4 ''-yl]}-phenonaphthazine (BPZTPA) and 5,12-bis{N-[4,4'-bis(methoxy-phenyl)aminophen-4'-phenonaphthazine (MeO-BPZTPA) have been designed and employed in the fabrication of perovskite solar cells. BPZTPA and MeO-BPZTPA exhibit excellent thermal stabilities, hole mobilities (similar to 10(-4) cm(2)/(V.s)) and suitable HOMO levels (-5.34 and-5.29 eV, respectively) relative to the valence band of the CH3NH3PbI3 and Au work function, showing their potential as alternative hole-transporting materials (HTMs). Meanwhile, the corresponding mesoporous TiO2/CH3NH3PbI3/HTM/Au devices are investigated, and the best power conversion efficiency of 10.36% has been achieved for MeO-BPZTPA without using p-type dopant. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
文摘we have synthesised a series of new optically nonlinear organic materials of cinnamylidene-acetophenone derivatives which have large nonl inear optical susceptibilities and short cut-off wavelengths.
基金Support by the National Natural Science Foundation of China(No.21563002)the Natural Science Foundation of Inner Mongolia Autonomous Region(No.2015MS0201)the Research Program of Sciences at Universities of Inner Mongolia Autonomous Region(No.NJZZ235)
文摘A series of star-shaped molecules with benzene core and naphthalimides derivatives end groups have been designed to explore their optical,electronic,and charge transport properties as charge transport and/or luminescent materials for organic light-emitting diodes（OLEDs）. The frontier molecular orbitals（FMOs） analysis has turned out that the vertical electronic transitions of absorption and emission are characterized as intramolecular charge transfer（ICT）. The calculated results show that the optical and electronic properties of star-shaped molecules are affected by the substituent groups in N-position of 1,8-naphthalimide ring. Our results suggest that star-shaped molecules with n-butyl（1）,benzene（2）,thiophene（3）,thiophene S？,S？-dioxide（4）,benzo[c][1,2,5]thiadiazole（5）,and 2,7a-dihydrobenzo[d]thiazole（6） fragments are expected to be promising candidates for luminescent and electron transport materials for OLEDs. This study should be helpful in further theoretical investigations on such kind of systems and also to the experimental study for charge transport and/or luminescent materials for OLEDs.
基金financially supported by the Natural Science Foundation of Beijing (No. L182062)the Beijing Nova program (Z171100001117077)+5 种基金the Yue Qi Young Scholar Project of China University of Mining & Technology (Beijing) (No. 2017QN17)the Fundamental Research Funds for the Central Universities (No.2014QJ02)the program for the Development of Science and Technology of Jilin Province (Nos. 20190201309JC and 20190101009JH)the Project of Development and Reform Commission of Jilin Province (No. 2019C042-1)the support from Natural Sciences and Engineering Research Council of Canada (NSERC)the University of Waterloo.
文摘Lithium-sulfur(Li-S) battery is a potential energy storage technology with high energy density and low cost. However, the gap between theoretical expectation and practical performance limits its wide implementation. Herein, we report a nitrogen-doped porous carbon derived from biomass pomelo peel as sulfur host material for Li-S batteries. The hierarchical porous architecture and the polar surface introduced by N-doping render a favorable combination of physical and chemical sulfur confinements as well as an expedite electron/ion transfer, thus contributing to a facilitated and stabilized sulfur electrochemistry. As a result, the corresponding sulfur composite electrodes exhibit an ultrahigh initial capacity of 1534.6 mAh g^-1, high coulombic efficiency over 98% upon 300 cycles, and decent rate capability up to 2 C. This work provides an economical and effective strategy for the fabrication of advanced carbonaceous sulfur host material as well as the significant improvement of Li-S battery performance.
基金financial support from Natural Science Foundation of China(61605134)Basic Sichuan Applied Research Project(2019YJ0078)the Innovative Spark Project of Sichuan University(2018SCUH0043)
文摘At present,two-dimensional(2D)materials have shown great application potential in numerous fields based on their physical chemical and electronic properties.Raman spectroscopy and de-rivative techniques are effective tools for characterizing 2D materials.Raman spectroscopy conveys lots of knowledge on 2D materials,including layer number,doping type,strain and interlayer coupling.This review summarized advanced applications of Raman spectroscopy in 2D materials.The challenges and possible applied directions of Raman spectroscopy to 2D materials are discussed in detail.
基金supported by the projects of Sichuan Normal University(DJ GX2017017 and DJ GX2017018)
文摘Biomass-derived carbon materials have aroused widespread concern as host material of sulfur to enhance electrochemical performances for lithium–sulfur batteries. Herein, goat hair, as a low-cost and eco-friendly precursor, is employed to fabricate cauliflower-like in-situ nitrogen, oxygen and phosphorus tri-doped porous biomass carbon(NOPC) by a facile activation with H_3PO_4 and carbonization process.The morphology and microstructure of NOPC can be readily tuned by altering pyrolysis temperature. The as-prepared NOPC matrix material carbonized at 600 °C possesses 3D hierarchical porous structure, high specific surface area(535.352 m^2 g^(-1)), and appropriate pore size and pore size distribution. Encapsulating sulfur into the NOPC depends on a stem-melting technology as cathode materials of Li–S batteries. Due to the synergistic effect of special physical structure and inherent tri-doping of N, O and P, electrons and ions transfer and utilization of active sulfur in the materials are improved, and the shuttle behaviors of soluble lithium polysulfides are also mitigated. Consequently, the S/NOPC-600 composite exhibits excellent electrochemical performance, giving a high initial discharge capacity of 1185 mA h g^(-1) at 0.05 C and maintaining a relatively considerable capacity of 489 m A h g^(-1) at 0.2 C after 300 cycles. Our work shows that a promising candidate for cathode material of Li–S batteries can be synthesized using low-cost and renewable biomass materials by a facile process.
文摘Based on synthesizing pure spinel type lithium manganese oxides,the derivations such as LiMn1.5Ti0.5-O4,LiMn1.5Fe0.5O4,LiMn1 .5Ni0.5O4 and LiMn1.5Zn0.5O4 were prepared using solid- step-sintering method. The structures were characterized by using XRD,SEM and laser granulometer. The electrochemical measurement results show that the elemen t of iron or nickel can raise the discharging plateau voltage of LiMn2O4,an d element titanium improves the electrochemistry property of LiMn2O4 little,while element zinc destroys the electrochemistry property of LiMn2O4. The i nfluence of elements of titanium,iron,nickel,or zinc on the structure of LiMn 2O4 pure phase was discussed from the viewpoint of structural chemistry.
文摘In the paper the elasticity tensor and the relation between stress and strain of transverse isotropic material and isotropic material are deduced by tensor derivate. From the derivation the reason why there are two independent elasticity coefficients for isotropic elastic material and five for transverse isotropic elastic material can be seen more clearly.
文摘In order to formulate a general expression of elastic tensor for anisotropic materials, a method of tensor derivative is used for determining relationship between fourth-order elastic tensor and second-order structure tensor that has satisfied material symmetrical conditions. From this general expression of elastic tensor, specific expressions of elastic tensor for different anisotropic materials, such as isotropic materials, transverse isotropic materials and orthogonal-anisotropic materials, can be deduced. This expression underlies the scalar description of anisotropic factors, which are used for classifying and analyzing anisotropic materials. Cubic crystals are analyzed macroscopically by means of the general expression and anisotropic factor.
