Developing single-atom catalysts(SACs) for electrochemical devices is a frontier in energy conversion.The comparison of stability,activity and selectivity between various single atoms is one of the main research focus...Developing single-atom catalysts(SACs) for electrochemical devices is a frontier in energy conversion.The comparison of stability,activity and selectivity between various single atoms is one of the main research focuses in SACs.However,the in-depth understanding of the role that the coordination atoms of single atom play in the catalytic process is lacking.Herein,we proposed a graphene-like boroncarbon-nitride(BCN) monolayer as the support of single metal atom.The electrocatalytic nitrogen reduction reaction(eNRR) performances of 3 d,4 d transition metal(TM) atoms embedded in defective BCN were systematically investigated by means of density functional theory(DFT) computations.Our study shows that the TM-to-N and B-to-N π-back bonding can contribute to the activation of N_(2).Importantly,a combined effect is revealed between single TM atom and boron atom on eNRR:TM atom enhances the nitrogen reduction process especially in facilitating the N_(2) adsorption and the NH3 desorption,while boron atom modulates the bonding strength of key intermediates by balancing the charged species.Furthermore,Nb@BN3 possesses the highest electrocata lytic activity with limiting potential of-0.49 V,and exhibits a high selectivity for nitrogen reduction reaction(NRR) to ammonia compared with hydrogen evolution reaction(HER).As such,this work can stimulate a research doorway for designing multi-active sites of the anchored single atoms and the innate atoms of substrate based on the mechanistic insights to guide future eNRR research.展开更多
High resolution and full-color light-emitting diodes require precise and efficient patterning of light-emitting structures containing quantum dots or nanocrystals.We report light-induced inverted patterning of nanocry...High resolution and full-color light-emitting diodes require precise and efficient patterning of light-emitting structures containing quantum dots or nanocrystals.We report light-induced inverted patterning of nanocrystals in glasses for micro-light-emitting diodes.Ultrafast laser pulse induces structural destruction and amorphization of nanocrystals in glasses,forming inverted luminescent patterns.High-throughput patterning of micrometer-scale,thermally stable,and highly photoluminescent structures in nanocrystals embedded glass is realized.This patterning method provides a novel way to fabricate high-performance and ultrahigh-resolution color conversion layers for micrometer-scale light-emitting diodes.展开更多
Biomimetic superhydrophobic(SH)coatings have emerged as a promising alternative to traditional room temperature vulcanizing(RTV)silicone rubber coatings for improving the flashover strength of insulators.However,organ...Biomimetic superhydrophobic(SH)coatings have emerged as a promising alternative to traditional room temperature vulcanizing(RTV)silicone rubber coatings for improving the flashover strength of insulators.However,organic contamination occurs in outdoor applications and thus a superamphiphobic(SAP)surface is more desirable but not yet reported for improving flashover performance.Herein,we developed a novel anti-flashover technique by fabricating robust SAP coating with unique gradient and micro-nanoscale hierarchical architecture.The SAP coating was fabricated by sequentially spray-depositing a resin-based primer and a silica-based topcoat on substrates(i.e.,glass slides and insulators).The primer not only functions as an adhesive offering strong adhesion to the substrate but also offers a micromastoid-like structure facilitating the subsequent formation of hierarchical micro-nanostructure.The appropriate spraying pressure leads to a diffusion of the fluorocarbon-modified silica nanoparticles into the primer to form a unique gradient structure,by analogy to inserting bullets into a wood.These features render the SAP coating excellent robustness with strong abrasive resistance,excellent ultraviolet(UV)resistance,and excellent chemical and thermal stability.Pollution flashover property of the SAP coating was explored and compared with that of SH and RTV specimens,from which a novel organic-contamination model to evaluate the flashover performance was proposed.The coated SAP glass insulator demonstrated 42.9%pollution flashover voltage improvement than RTV-coated insulator.These stated unique features reveal the convincing potential of the present SAP coatings to be applied for not only outdoor transmission line insulators for antiflashover but also other fields for self-cleaning,anti-fouling,and anti-icing.展开更多
This paper describes an elaborate study on obtaining Ag/PMMA(polymethyl methacrylate)leaky hollow waveguide which has a large aperture and low loss in transmitting solar energy.Through analyses and comparison,a quartz...This paper describes an elaborate study on obtaining Ag/PMMA(polymethyl methacrylate)leaky hollow waveguide which has a large aperture and low loss in transmitting solar energy.Through analyses and comparison,a quartz capillary with the inner diameter of 2 mm was chosen as hollow waveguide.We used the xenon light source,which has the similar spectrum as the sunlight to test and analyze the performance of the Ag/PMMA leakage hollow waveguide.The results are consistent with the transmitted theory of the dielectric/metal leaky type well.Meanwhile,the Ag/PMMA leaky-type hollow waveguide in this work had good qualities.Therefore,it will be a satisfactory medium for solar energy transmission.展开更多
基金the Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions of China(grant number 161008)the Basic Research Program of Shenzhen(grant number JCYJ20190809120015163)+4 种基金the Key R&D Program of Hubei province(grant number 2020CFA087)the Fundamental Research Funds for the Central Universities(grant number 2019III-034)the Xiamen University Malaysia Research Fund(grant number XMUMRF/2019-C3/IENG/0013)the Ministry of Higher Education(MOHE)Malaysia under the Fundamental Research Grant Scheme(FRGS)(grant number FRGS/1/2020/TK02/XMU/02/1)the Overseas Expertise Introduction Project(111 project)for Discipline Innovation of China(grant number B18038)。
文摘Developing single-atom catalysts(SACs) for electrochemical devices is a frontier in energy conversion.The comparison of stability,activity and selectivity between various single atoms is one of the main research focuses in SACs.However,the in-depth understanding of the role that the coordination atoms of single atom play in the catalytic process is lacking.Herein,we proposed a graphene-like boroncarbon-nitride(BCN) monolayer as the support of single metal atom.The electrocatalytic nitrogen reduction reaction(eNRR) performances of 3 d,4 d transition metal(TM) atoms embedded in defective BCN were systematically investigated by means of density functional theory(DFT) computations.Our study shows that the TM-to-N and B-to-N π-back bonding can contribute to the activation of N_(2).Importantly,a combined effect is revealed between single TM atom and boron atom on eNRR:TM atom enhances the nitrogen reduction process especially in facilitating the N_(2) adsorption and the NH3 desorption,while boron atom modulates the bonding strength of key intermediates by balancing the charged species.Furthermore,Nb@BN3 possesses the highest electrocata lytic activity with limiting potential of-0.49 V,and exhibits a high selectivity for nitrogen reduction reaction(NRR) to ammonia compared with hydrogen evolution reaction(HER).As such,this work can stimulate a research doorway for designing multi-active sites of the anchored single atoms and the innate atoms of substrate based on the mechanistic insights to guide future eNRR research.
基金supported by the Key Research and Development Program of Hubei Province (No.2021BAA206).
文摘High resolution and full-color light-emitting diodes require precise and efficient patterning of light-emitting structures containing quantum dots or nanocrystals.We report light-induced inverted patterning of nanocrystals in glasses for micro-light-emitting diodes.Ultrafast laser pulse induces structural destruction and amorphization of nanocrystals in glasses,forming inverted luminescent patterns.High-throughput patterning of micrometer-scale,thermally stable,and highly photoluminescent structures in nanocrystals embedded glass is realized.This patterning method provides a novel way to fabricate high-performance and ultrahigh-resolution color conversion layers for micrometer-scale light-emitting diodes.
基金financial supports by the Young Scientists Fund of the National Natural Science Foundation of China (11604249)the Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions of China (161008)+3 种基金the Foundation of the State Key Laboratory of Optical Fiber and Cable Manufacture Technology (SKLD1602)the State Key Laboratory of Refractors and Metallurgy (G201605), the Fundamental Research Funds for the Central Universities (2019-III-034)the Research Board of the State Key Laboratory of Silicate Materials for Architecturesfinancial supports and grants from Xiamen University Malaysia,the Xiamen University Malaysia Research Fund (XMUMRF/2019-C3/ IENG/0013)
基金the project“Synthesis and Application of Superhydrophobic Self-cleaning Materials for Electric Engineering”(No.6111901321)Overseas Expertise Introduction Project(111 project)for Discipline Innovation of China(No.B18038)the State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)Open Foundation(No.SYSJJ2021-02).
文摘Biomimetic superhydrophobic(SH)coatings have emerged as a promising alternative to traditional room temperature vulcanizing(RTV)silicone rubber coatings for improving the flashover strength of insulators.However,organic contamination occurs in outdoor applications and thus a superamphiphobic(SAP)surface is more desirable but not yet reported for improving flashover performance.Herein,we developed a novel anti-flashover technique by fabricating robust SAP coating with unique gradient and micro-nanoscale hierarchical architecture.The SAP coating was fabricated by sequentially spray-depositing a resin-based primer and a silica-based topcoat on substrates(i.e.,glass slides and insulators).The primer not only functions as an adhesive offering strong adhesion to the substrate but also offers a micromastoid-like structure facilitating the subsequent formation of hierarchical micro-nanostructure.The appropriate spraying pressure leads to a diffusion of the fluorocarbon-modified silica nanoparticles into the primer to form a unique gradient structure,by analogy to inserting bullets into a wood.These features render the SAP coating excellent robustness with strong abrasive resistance,excellent ultraviolet(UV)resistance,and excellent chemical and thermal stability.Pollution flashover property of the SAP coating was explored and compared with that of SH and RTV specimens,from which a novel organic-contamination model to evaluate the flashover performance was proposed.The coated SAP glass insulator demonstrated 42.9%pollution flashover voltage improvement than RTV-coated insulator.These stated unique features reveal the convincing potential of the present SAP coatings to be applied for not only outdoor transmission line insulators for antiflashover but also other fields for self-cleaning,anti-fouling,and anti-icing.
基金funded by the State Key Development Program for Basic Research of China(Grant No.2009CB939704)the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT0547)。
文摘This paper describes an elaborate study on obtaining Ag/PMMA(polymethyl methacrylate)leaky hollow waveguide which has a large aperture and low loss in transmitting solar energy.Through analyses and comparison,a quartz capillary with the inner diameter of 2 mm was chosen as hollow waveguide.We used the xenon light source,which has the similar spectrum as the sunlight to test and analyze the performance of the Ag/PMMA leakage hollow waveguide.The results are consistent with the transmitted theory of the dielectric/metal leaky type well.Meanwhile,the Ag/PMMA leaky-type hollow waveguide in this work had good qualities.Therefore,it will be a satisfactory medium for solar energy transmission.
