Subwavelength metal-dielectric plasmonic metasurfaces enable light management beyond the diffraction limit.However,a costeffective and reliable fabrication method for such structures remains a major challenge hinderin...Subwavelength metal-dielectric plasmonic metasurfaces enable light management beyond the diffraction limit.However,a costeffective and reliable fabrication method for such structures remains a major challenge hindering their full exploitation.Here,we propose a simple yet powerful manufacturing route for plasmonic metasurfaces based on a bottom-up approach.The fabricated metasurfaces consist of a dense distribution of randomly oriented nanoscale scatterers composed of aluminum(Al)nanohole-disk pairs,which exhibit angle-independent scattering that is tunable across the entire visible spectrum.The macroscopic response of the metasurfaces is controlled via the properties of an isolated Al nanohole-disk pair at the nanoscale.In addition,the optical field confinement at the scatterers and their random distribution of sizes result in a strongly enhanced Raman signal that enables broadly tunable excitation using a single substrate.This unique combination of a reliable and lithography-free methodology with the use of aluminum permits the exploitation of the full potential of random plasmonic metasurfaces for diagnostics and coloration.展开更多
Carbon dioxide(CO_(2))is the main greenhouse gas,whereas it is also a nontoxic,abundant,cheap carbon and oxygen resource.The copolymerization of CO_(2) with epoxide presents a sustainable approach to the synthesis of ...Carbon dioxide(CO_(2))is the main greenhouse gas,whereas it is also a nontoxic,abundant,cheap carbon and oxygen resource.The copolymerization of CO_(2) with epoxide presents a sustainable approach to the synthesis of biodegradable polymers,which upcycles the waste into wealth.Metal complex catalyst plays the central role in the reaction,since it provides oxophilic and Lewis acidic active center both for monomer activation and chain end stabilization,and nucleophiles as Lewis base for initiation.However,heavy metal catalyst with certain toxicity such as cobalt undisputedly dominates the copolymerization catalysis which comprises the overall sustainability.To circumvent the potential environmental hazard,developing highly active catalyst composed of green metals is of great importance especially when the polymer was utilized for agriculture purpose.This work reviews the development of sustainable metal catalysts for the production of CO_(2) copolymer,centered by Al,Mg,Ti,Fe,generally acknowledged as low toxic,environmentally benign,biocompatible,and also abundant in earth's crust.Emphasis is placed in recent five years where several historic examples are also included to construct a full picture of the sustainable catalysis explored to date.展开更多
Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. U...Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. Up to date, reaction delay of Al particles is still limited by the efficiency of mass and heat transfer from oxidizers to Al particles. To address this issue, a homogeneous fuel-oxidizer assembly has recently become a promising strategy. In this work, oxidizer-activated Al fuel particles(ALG) were prepared with glycidyl azide polymer(GAP) as the oxidizer. The ALG was in uniform spherical shape and core-shell structure with shell layer of around 5 nm which was observed by scanning electron microscope and transmission electron microscope. The localized nanoscale mid-IR measurement detected the uniform distribution of characteristic absorption bond of GAP in the shell layer which confirmed the homogenous fuel-oxidizer structure of ALG. A thermal gravimetric analysis of ALG at ultrafast heating rate of 1000℃/min under argon atmosphere was conducted. The decomposition of GAP finished much earlier than that of GAP at heating rate of 10℃/min. Under ultrafast high laser fluence, the reaction response of ALG was characterized and compared with that of micro-sized Al(μAl). With the increase of laser energy, the propagation distance of the shock wave increased. However, the velocity histories were nearly the same when energies were lower than 299 mJ or higher than 706 mJ. The propagation distance of the shock wave for ALG was 0.5 mm larger than that for μAl at 2.1 μs. The underwater explosion showed the peak pressure and the shock wave energy of the ALG-based explosive were both higher than those of the μAl-based explosive at 2.5 m. This study shows the feasibility to improve the energy release of Al-based explosives via using the oxidizer-activated Al fuel particles with energetic polymer as the oxidizer.展开更多
The thermal conductivity of polymer composites can be enhanced by the vertical alignment of anisotropic aluminum nitride(AlN)platelet fillers in polymer matrices.The AlN platelets in polymer matrix were aligned in the...The thermal conductivity of polymer composites can be enhanced by the vertical alignment of anisotropic aluminum nitride(AlN)platelet fillers in polymer matrices.The AlN platelets in polymer matrix were aligned in the direction of in-plane and out-of-plane by using the doctor blading and the lamination process.The alignment of AlN plates in the out-of-plane or the in-plane direction has been confirmed by XRD and FE-SEM investigations.The polymer composite with the out-of-plane aligned AlN platelets showed almost 1.5 times or 2 times higher thermal conductivity than those with the AlN spheres or the in-plane aligned AlN platelets at the same filler content,respectively.This result could be attributed to the improvement of thermal pathway generated along the plane of platelets and the decrease of interfaces between the filler and the polymer.展开更多
Aluminum-sulfur(Al-S)batteries are regarded as a desirable candidate for large-scale energy storage be-cause of their high energy density and abundant natural resources of electrode materials.To address the critical i...Aluminum-sulfur(Al-S)batteries are regarded as a desirable candidate for large-scale energy storage be-cause of their high energy density and abundant natural resources of electrode materials.To address the critical issues of low discharge voltage and rapid capacity decay in Al-S batteries,here an electrocatalyst-assisted gel-polymer electrolyte(GPE)-based Al-S battery is fabricated using platinum nanoparticles deco-rated platinum/nitrogen co-doped graphene(PtNG)as sulfur host for positive electrode and metal-organic frameworks(MOF)filled GPE(MOF@GPE)as solid electrolyte.Pt-based active sites derived from Pt nan-oclusters’surface and atomically dispersed Pt-N_(2) chemical bonds in PtNG can catalyze the decomposition of sulfur and polysulfides in the electrochemical process,greatly accelerating the sulfur redox kinetics.Furthermore,the MOF fillers in MOF@GPE electrolyte significantly inhibit the shuttle effect of polysul-fides,efficiently improving the utilization of sulfur.Consequently,the established Al-S battery delivers a specific capacity of 1009 mAh g^(−1) with a discharge plateau of∼0.95 V,along with a capacity retention of 65% after 300 cycles,revealing ultrahigh energy density and long cycle life.Such a strategy of combin-ing electrocatalyst and MOF-based gel electrolyte affords a fresh plateau for promoting the rechargeable ability of Al-S batteries,advancing remarkable routes for achieving efficient and stable energy storage devices.展开更多
Rechargeable aluminum batteries are believed as a promising next-generation energy-storage system due to abundant low-cost Al sources and high volumetric specific capacity.The Al-storage cathodes,however,are plagued b...Rechargeable aluminum batteries are believed as a promising next-generation energy-storage system due to abundant low-cost Al sources and high volumetric specific capacity.The Al-storage cathodes,however,are plagued by strong electrostatic interaction between host materials and carrier ions,leading to large overpotential and undesired cycling stability as well as sluggish ion diffusion kinetics.Herein,sulfur-linked carbonyl polymer based on perylene-3,4,9,10-tetracarboxylic dianhydride(PTCDA) as the cathode materials for ABs is proposed,which demonstrates a small voltage polarization(135 mV),a reversible capacity of 110 mAh g^(-1) at 100 mA g^(-1) even after 1200 cycles,and rapid Al-storage kinetics.Compared with PTCDA,the sulfide polymer possesses higher working voltage because of its lower LUMO energy level according to theoretical calculation.The ordered carbonyl active sites in sulfide polymer contribute to the maximized material utilization and rapid ion coordination and dissociation,resulting in superior rate capability.Besides,the bridged thioether bonds endow the polysulfide with robust and flexible structure,which inhibits the dissolution of active materials and improves cycling stability.This work implies the importance of ordered arrangement of redox active moieties for organic electrode,which provides the theoretical direction for the structural design of organic materials applied in multivalent-ion batteries.展开更多
[AlO4Al12(OH)24(H2O)12]7+ (Al13) formation in electrolysis process is studied. The results detected by27Al NMR spectroscopy show that high content of Al13 polymer is formed in the partially hydrolyzed aluminum solutio...[AlO4Al12(OH)24(H2O)12]7+ (Al13) formation in electrolysis process is studied. The results detected by27Al NMR spectroscopy show that high content of Al13 polymer is formed in the partially hydrolyzed aluminum solution prepared by controlled electrolysis process. In the produced electrolyte of total Al concentration ([AlT]) 2.0 mol · L?1 with a basicity (B = OH/Al molar ratios) of 2.0, the content of Al13 polymer is over 60% of total Al. Dynamic light scattering shows that the size distribution of the final electrolyte solutions ([AlT] = 2.0 mol · L?1) is trimodal with B = 2.0 and bimodal with B = 2.5. The aggregates of Al13 complexes increase the particle size of partially hydrolyzed aluminum solution.展开更多
Aluminum nanocrystals(Al NCs)are sustainable plasmonic nanomaterials with unique localized surface plasmonic resonance(LSPR)in the ultraviolet(UV)region.Chemical synthesis of sub-100-nm Al NCs remains a considerable c...Aluminum nanocrystals(Al NCs)are sustainable plasmonic nanomaterials with unique localized surface plasmonic resonance(LSPR)in the ultraviolet(UV)region.Chemical synthesis of sub-100-nm Al NCs remains a considerable challenge due to the lack of effective ligands to control their growth.Here,we describe a precise size-controlled synthesis of small colloidal Al NCs(25–100 nm)with strong and tunable LSPR peak from 250 to 372 nmin the UV spectral region by the use of poly(ethylene oxide)(PEO)as a polydentate surface ligand.展开更多
基金supported by the Karlsruhe School of Optics and Photonics(KSOP,www.ksop.idschools.kit.edu)the Karlsruhe Nano Micro Facility(KNMF,www.kit.edu/knmf)+3 种基金a Helmholtz Research Infrastructure at Karlsruhe Institute of Technology(KIT,www.kit.edu)a BBSRC David Phillips fellowship(BB/K014617/1)ERC-2014-STG H2020639088support from the EPSRC(EP/G060649/1).
文摘Subwavelength metal-dielectric plasmonic metasurfaces enable light management beyond the diffraction limit.However,a costeffective and reliable fabrication method for such structures remains a major challenge hindering their full exploitation.Here,we propose a simple yet powerful manufacturing route for plasmonic metasurfaces based on a bottom-up approach.The fabricated metasurfaces consist of a dense distribution of randomly oriented nanoscale scatterers composed of aluminum(Al)nanohole-disk pairs,which exhibit angle-independent scattering that is tunable across the entire visible spectrum.The macroscopic response of the metasurfaces is controlled via the properties of an isolated Al nanohole-disk pair at the nanoscale.In addition,the optical field confinement at the scatterers and their random distribution of sizes result in a strongly enhanced Raman signal that enables broadly tunable excitation using a single substrate.This unique combination of a reliable and lithography-free methodology with the use of aluminum permits the exploitation of the full potential of random plasmonic metasurfaces for diagnostics and coloration.
基金The authors greatly appreciated the financial support from National Natural Science Foundation of China(Grant No.51988102).
文摘Carbon dioxide(CO_(2))is the main greenhouse gas,whereas it is also a nontoxic,abundant,cheap carbon and oxygen resource.The copolymerization of CO_(2) with epoxide presents a sustainable approach to the synthesis of biodegradable polymers,which upcycles the waste into wealth.Metal complex catalyst plays the central role in the reaction,since it provides oxophilic and Lewis acidic active center both for monomer activation and chain end stabilization,and nucleophiles as Lewis base for initiation.However,heavy metal catalyst with certain toxicity such as cobalt undisputedly dominates the copolymerization catalysis which comprises the overall sustainability.To circumvent the potential environmental hazard,developing highly active catalyst composed of green metals is of great importance especially when the polymer was utilized for agriculture purpose.This work reviews the development of sustainable metal catalysts for the production of CO_(2) copolymer,centered by Al,Mg,Ti,Fe,generally acknowledged as low toxic,environmentally benign,biocompatible,and also abundant in earth's crust.Emphasis is placed in recent five years where several historic examples are also included to construct a full picture of the sustainable catalysis explored to date.
基金National Natural Science Foundation of China(Grant No.11832006,U1530262,21975024).
文摘Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. Up to date, reaction delay of Al particles is still limited by the efficiency of mass and heat transfer from oxidizers to Al particles. To address this issue, a homogeneous fuel-oxidizer assembly has recently become a promising strategy. In this work, oxidizer-activated Al fuel particles(ALG) were prepared with glycidyl azide polymer(GAP) as the oxidizer. The ALG was in uniform spherical shape and core-shell structure with shell layer of around 5 nm which was observed by scanning electron microscope and transmission electron microscope. The localized nanoscale mid-IR measurement detected the uniform distribution of characteristic absorption bond of GAP in the shell layer which confirmed the homogenous fuel-oxidizer structure of ALG. A thermal gravimetric analysis of ALG at ultrafast heating rate of 1000℃/min under argon atmosphere was conducted. The decomposition of GAP finished much earlier than that of GAP at heating rate of 10℃/min. Under ultrafast high laser fluence, the reaction response of ALG was characterized and compared with that of micro-sized Al(μAl). With the increase of laser energy, the propagation distance of the shock wave increased. However, the velocity histories were nearly the same when energies were lower than 299 mJ or higher than 706 mJ. The propagation distance of the shock wave for ALG was 0.5 mm larger than that for μAl at 2.1 μs. The underwater explosion showed the peak pressure and the shock wave energy of the ALG-based explosive were both higher than those of the μAl-based explosive at 2.5 m. This study shows the feasibility to improve the energy release of Al-based explosives via using the oxidizer-activated Al fuel particles with energetic polymer as the oxidizer.
基金a financial support from Korean Ministry of Industry,Energy,and Commerce through the program of Industrial Core Material development.(Project No.10038631)。
文摘The thermal conductivity of polymer composites can be enhanced by the vertical alignment of anisotropic aluminum nitride(AlN)platelet fillers in polymer matrices.The AlN platelets in polymer matrix were aligned in the direction of in-plane and out-of-plane by using the doctor blading and the lamination process.The alignment of AlN plates in the out-of-plane or the in-plane direction has been confirmed by XRD and FE-SEM investigations.The polymer composite with the out-of-plane aligned AlN platelets showed almost 1.5 times or 2 times higher thermal conductivity than those with the AlN spheres or the in-plane aligned AlN platelets at the same filler content,respectively.This result could be attributed to the improvement of thermal pathway generated along the plane of platelets and the decrease of interfaces between the filler and the polymer.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51725401 and 51874019)the Fundamental Research Funds for the Central Universities(No.FRF-TP-17-002C2)。
文摘Aluminum-sulfur(Al-S)batteries are regarded as a desirable candidate for large-scale energy storage be-cause of their high energy density and abundant natural resources of electrode materials.To address the critical issues of low discharge voltage and rapid capacity decay in Al-S batteries,here an electrocatalyst-assisted gel-polymer electrolyte(GPE)-based Al-S battery is fabricated using platinum nanoparticles deco-rated platinum/nitrogen co-doped graphene(PtNG)as sulfur host for positive electrode and metal-organic frameworks(MOF)filled GPE(MOF@GPE)as solid electrolyte.Pt-based active sites derived from Pt nan-oclusters’surface and atomically dispersed Pt-N_(2) chemical bonds in PtNG can catalyze the decomposition of sulfur and polysulfides in the electrochemical process,greatly accelerating the sulfur redox kinetics.Furthermore,the MOF fillers in MOF@GPE electrolyte significantly inhibit the shuttle effect of polysul-fides,efficiently improving the utilization of sulfur.Consequently,the established Al-S battery delivers a specific capacity of 1009 mAh g^(−1) with a discharge plateau of∼0.95 V,along with a capacity retention of 65% after 300 cycles,revealing ultrahigh energy density and long cycle life.Such a strategy of combin-ing electrocatalyst and MOF-based gel electrolyte affords a fresh plateau for promoting the rechargeable ability of Al-S batteries,advancing remarkable routes for achieving efficient and stable energy storage devices.
基金supported by the Ministry of Science and Technology of China (2019YFA0705600 and 2017YFA0206700)the National Natural Science Foundation of China (21805141,22005155 and 52072186)+2 种基金the 111 Project from the Ministry of Education of China (B12015)the Fundamental Research Funds for the Central Universities (92122001)the Young Elite Scientist Sponsorship Program by CAST (2019QNRC001)。
文摘Rechargeable aluminum batteries are believed as a promising next-generation energy-storage system due to abundant low-cost Al sources and high volumetric specific capacity.The Al-storage cathodes,however,are plagued by strong electrostatic interaction between host materials and carrier ions,leading to large overpotential and undesired cycling stability as well as sluggish ion diffusion kinetics.Herein,sulfur-linked carbonyl polymer based on perylene-3,4,9,10-tetracarboxylic dianhydride(PTCDA) as the cathode materials for ABs is proposed,which demonstrates a small voltage polarization(135 mV),a reversible capacity of 110 mAh g^(-1) at 100 mA g^(-1) even after 1200 cycles,and rapid Al-storage kinetics.Compared with PTCDA,the sulfide polymer possesses higher working voltage because of its lower LUMO energy level according to theoretical calculation.The ordered carbonyl active sites in sulfide polymer contribute to the maximized material utilization and rapid ion coordination and dissociation,resulting in superior rate capability.Besides,the bridged thioether bonds endow the polysulfide with robust and flexible structure,which inhibits the dissolution of active materials and improves cycling stability.This work implies the importance of ordered arrangement of redox active moieties for organic electrode,which provides the theoretical direction for the structural design of organic materials applied in multivalent-ion batteries.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 50108016).
文摘[AlO4Al12(OH)24(H2O)12]7+ (Al13) formation in electrolysis process is studied. The results detected by27Al NMR spectroscopy show that high content of Al13 polymer is formed in the partially hydrolyzed aluminum solution prepared by controlled electrolysis process. In the produced electrolyte of total Al concentration ([AlT]) 2.0 mol · L?1 with a basicity (B = OH/Al molar ratios) of 2.0, the content of Al13 polymer is over 60% of total Al. Dynamic light scattering shows that the size distribution of the final electrolyte solutions ([AlT] = 2.0 mol · L?1) is trimodal with B = 2.0 and bimodal with B = 2.5. The aggregates of Al13 complexes increase the particle size of partially hydrolyzed aluminum solution.
基金the National Natural Science Foundation of China(21975094,21674042,and 21534004)for financial support.K.L.and T.S.thank the Interdisciplinary Innovation Project of the First Hospital of Jilin University(JDYYJCHX001).
文摘Aluminum nanocrystals(Al NCs)are sustainable plasmonic nanomaterials with unique localized surface plasmonic resonance(LSPR)in the ultraviolet(UV)region.Chemical synthesis of sub-100-nm Al NCs remains a considerable challenge due to the lack of effective ligands to control their growth.Here,we describe a precise size-controlled synthesis of small colloidal Al NCs(25–100 nm)with strong and tunable LSPR peak from 250 to 372 nmin the UV spectral region by the use of poly(ethylene oxide)(PEO)as a polydentate surface ligand.
