Ambient electrocatalytic nitrogen fixation is an emerging technology for green ammonia synthesis,but the absence of optimized,stable and performant catalysts can render its practical application challenging.Herein,bim...Ambient electrocatalytic nitrogen fixation is an emerging technology for green ammonia synthesis,but the absence of optimized,stable and performant catalysts can render its practical application challenging.Herein,bimetallic NiCo boride nanoparticles confined in MXene are shown to accomplish highperformance nitrogen reduction electrolysis.Ta king advantage of the synergistic effect in specific compositions with unique electronic d and p orbits and typical architecture of rich nanosized particles embedded in the interconnected conductive network,the synthesized MXene@NiCoB composite demonstrates extensive improvements in nitrogen molecule chemisorption,active area exposure and charge transport.As a result,optimal NH3 yield rate of 38.7μg h^(-1) mgcat^(-1).and Faradaic efficiency of 6.92%are acquired in0.1 M Na_(2)SO_(4) electrolyte.Moreover,the great catalytic performance can be almost entirely maintained in the cases of repeatedly-cycled and long-term electrolysis.Theoretical investigations reveal that the nitrogen reduction reaction on MXene@NiCoB catalyst proceeds according to the distal pathway,with a distinctly-reduced energy barrier relative to the Co2B counterpart.This work may inspire a new route towards the rational catalyst design for the nitrogen reduction reaction.展开更多
Flexible electronic devices with mechanical properties like the soft tissues of human organs have great potential for the next generation of wearable and implantable electronic devices.Self-healing hydrogel composites...Flexible electronic devices with mechanical properties like the soft tissues of human organs have great potential for the next generation of wearable and implantable electronic devices.Self-healing hydrogel composites typically have high tensile strength,high electrical conductivity and damage repair properties and have wide applications in flexible electronics,such as human-computer interaction,health detection and soft robots.Various self-healing hydrogel composites have been developed to produce new stretchable conductive materials with satisfactory mechanical and selfhealing properties.This paper presents the fabrication of self-healing hydrogel composites and their application in flexible electronic devices.Firstly,the repair mechanism of physically cross-linked and chemically cross-linked self-healing hydrogel composites is presented.Secondly,self-healing double network hydrogels,self-healing nanocomposite hydrogels and double crosslinked self-healing hydrogel composites and their applications in flexible sensors,energy harvesting devices,energy storage devices and optical devices are presented and discussed.Finally,the challenges and prospects of self-healing hydrogel composites in flexible electronic devices in the future are presented.展开更多
The creation of ultrafine alloy nanoparticles(<5 nm) that can maintain surface activity and avoid aggregation for heterogeneous catalysis has received much attention and is extremely challenging.Here,ultrafine PtRh...The creation of ultrafine alloy nanoparticles(<5 nm) that can maintain surface activity and avoid aggregation for heterogeneous catalysis has received much attention and is extremely challenging.Here,ultrafine PtRh alloy nanoparticles imprisoned by the cavities of reduced chiral covalent imine cage(PtRh@RCC3) are prepared successfully by an organic molecular cage(OMC) confinement strategy,while the soluble RCC3 can act as a homogenizer to homogenize the heterogeneous PtRh alloy in solution.Moreover,the X-ray absorption near-edge structure(XANES) results show that the RCC3 can act as an electron-acceptor to withdraw electrons from Pt,leading to the formation of higher valence Pt atoms,which is beneficial to improving the catalytic activity for the reduction of 4-nitrophenol.Attributed to the synergistic effect of Pt/Rh atoms and the unique function of the RCC3,the reaction rate constants of Pt_(1)Rh_(16)@RCC3 are 49.6,8.2,and 5.5 times than those of the Pt_(1)Rh_(16)bulk,Pt@RCC3 and Rh@RCC3,respectively.This work provides a feasible strategy to homogenize heterogeneous alloy nanoparticle catalysts in solution,showing huge potential for advanced catalytic application.展开更多
Despite the intense research efforts directed to electrocatalytic nitrogen reduction reaction(eNRR),the NH_(3) yield and selectivity are still not up to the standard of practical application.Here,high-entropy perovski...Despite the intense research efforts directed to electrocatalytic nitrogen reduction reaction(eNRR),the NH_(3) yield and selectivity are still not up to the standard of practical application.Here,high-entropy perovskite oxides with composition Bax(FeCoNiZrY)_(0.2)O_(3−δ)(Bx(FCNZY)_(0.2)(x=0.9,1)are reported as eNRR catalysts.The eNRR activity of high-entropy perovskite oxide is enhanced by changing the nonstoichiometric metal elements at the A-site,thus generating additional oxygen vacancies.The NH_(3) yield and Faraday efficiency for B_(0.9)(FCNZY)_(0.2) are 1.51 and 1.95 times higher than those for B(FCNZY)_(0.2),respectively.The d-band center theory is used to theoretically predict the catalytically active center at the B-site,and as a result,nickel was identified as the catalytic site.The free energy values of the intermediate states in the optimal distal pathway show that the third protonation step(*NNH_(2)→*NNH_(3))is the rate-determining step and that the increase in oxygen vacancies in the high-entropy perovskite contributes to nitrogen adsorption and reduction.This work provides a framework for applying high-entropy structures with active site diversity for electrocatalytic nitrogen fixation.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21878063)Key Program of Shandong Provincial Natural Science Foundation(No.ZR2020KB011)+2 种基金Taishan Scholars Program of Shandong Province(No.tsqn201909119)financial support from the Flemish Government through the Moonshot cSBO project P2C(HBC.2019.0108)through long-term structural funding(Methusalem CASAS2,Meth/15/04)。
文摘Ambient electrocatalytic nitrogen fixation is an emerging technology for green ammonia synthesis,but the absence of optimized,stable and performant catalysts can render its practical application challenging.Herein,bimetallic NiCo boride nanoparticles confined in MXene are shown to accomplish highperformance nitrogen reduction electrolysis.Ta king advantage of the synergistic effect in specific compositions with unique electronic d and p orbits and typical architecture of rich nanosized particles embedded in the interconnected conductive network,the synthesized MXene@NiCoB composite demonstrates extensive improvements in nitrogen molecule chemisorption,active area exposure and charge transport.As a result,optimal NH3 yield rate of 38.7μg h^(-1) mgcat^(-1).and Faradaic efficiency of 6.92%are acquired in0.1 M Na_(2)SO_(4) electrolyte.Moreover,the great catalytic performance can be almost entirely maintained in the cases of repeatedly-cycled and long-term electrolysis.Theoretical investigations reveal that the nitrogen reduction reaction on MXene@NiCoB catalyst proceeds according to the distal pathway,with a distinctly-reduced energy barrier relative to the Co2B counterpart.This work may inspire a new route towards the rational catalyst design for the nitrogen reduction reaction.
基金supported by the Linyi University 2023 High-level Talents(PhD)Research Start-up Fund(Natural Sciences)(Nos.Z6124014 and Z6124015)the College Students’Innovation and Entrepreneurship Training Program(No.X202310452291)+1 种基金the Key Research and Development Project for the Highlevel Technological Talent of Lvlang City(Nos.2023GXYF09 and 2022RC15)Scientific Research Start-up Funds of Lyuliang University.
文摘Flexible electronic devices with mechanical properties like the soft tissues of human organs have great potential for the next generation of wearable and implantable electronic devices.Self-healing hydrogel composites typically have high tensile strength,high electrical conductivity and damage repair properties and have wide applications in flexible electronics,such as human-computer interaction,health detection and soft robots.Various self-healing hydrogel composites have been developed to produce new stretchable conductive materials with satisfactory mechanical and selfhealing properties.This paper presents the fabrication of self-healing hydrogel composites and their application in flexible electronic devices.Firstly,the repair mechanism of physically cross-linked and chemically cross-linked self-healing hydrogel composites is presented.Secondly,self-healing double network hydrogels,self-healing nanocomposite hydrogels and double crosslinked self-healing hydrogel composites and their applications in flexible sensors,energy harvesting devices,energy storage devices and optical devices are presented and discussed.Finally,the challenges and prospects of self-healing hydrogel composites in flexible electronic devices in the future are presented.
基金supported by the National Natural Science Foundation of China (52161135302 and 21674019)the Research Foundation of Flanders (FWO Grant No. 1298323N)+3 种基金the Natural Science Foundation of Shanghai (20ZR1401400)the Shanghai Scientific and Technological Innovation Project (18JC1410600)the Program of Shanghai Academic Research Leader (17XD1400100)the Fundamental Research Funds for the Central Universities and DHU Distinguished Young Professor Program (LZB2021002)。
文摘The creation of ultrafine alloy nanoparticles(<5 nm) that can maintain surface activity and avoid aggregation for heterogeneous catalysis has received much attention and is extremely challenging.Here,ultrafine PtRh alloy nanoparticles imprisoned by the cavities of reduced chiral covalent imine cage(PtRh@RCC3) are prepared successfully by an organic molecular cage(OMC) confinement strategy,while the soluble RCC3 can act as a homogenizer to homogenize the heterogeneous PtRh alloy in solution.Moreover,the X-ray absorption near-edge structure(XANES) results show that the RCC3 can act as an electron-acceptor to withdraw electrons from Pt,leading to the formation of higher valence Pt atoms,which is beneficial to improving the catalytic activity for the reduction of 4-nitrophenol.Attributed to the synergistic effect of Pt/Rh atoms and the unique function of the RCC3,the reaction rate constants of Pt_(1)Rh_(16)@RCC3 are 49.6,8.2,and 5.5 times than those of the Pt_(1)Rh_(16)bulk,Pt@RCC3 and Rh@RCC3,respectively.This work provides a feasible strategy to homogenize heterogeneous alloy nanoparticle catalysts in solution,showing huge potential for advanced catalytic application.
基金supported by the National Natural Science Foundation of China (52161135302, 21674019, and 51801075)the Research Foundation Flanders (G0F2322N)+8 种基金Shanghai Scientific and Technological Innovation Project (18JC1410600)the Program of the Shanghai Academic Research Leader (17XD1400100)the financial support from the Flemish Government through the Moonshot cSBO project P2C (HBC.2019.0108)the Long-term Structural Funding (Methusalem CASAS2, Meth/15/04)Interne Fondsen KU Leuven through project C3/20/067the support from the Research Foundation-Flanders (FWO) in the form of a doctoral fellowship (1SA3321N)the financial support from China Scholarship Council in the form of a visiting Ph.D. Student (File No. 202106790090)the LvLiang Cloud Computing Center of China, and the calculations were performed on a TianHe-2 systemthe characterizations supported by the Central Laboratory, School of Chemical and Material Engineering, Jiangnan University。
文摘Despite the intense research efforts directed to electrocatalytic nitrogen reduction reaction(eNRR),the NH_(3) yield and selectivity are still not up to the standard of practical application.Here,high-entropy perovskite oxides with composition Bax(FeCoNiZrY)_(0.2)O_(3−δ)(Bx(FCNZY)_(0.2)(x=0.9,1)are reported as eNRR catalysts.The eNRR activity of high-entropy perovskite oxide is enhanced by changing the nonstoichiometric metal elements at the A-site,thus generating additional oxygen vacancies.The NH_(3) yield and Faraday efficiency for B_(0.9)(FCNZY)_(0.2) are 1.51 and 1.95 times higher than those for B(FCNZY)_(0.2),respectively.The d-band center theory is used to theoretically predict the catalytically active center at the B-site,and as a result,nickel was identified as the catalytic site.The free energy values of the intermediate states in the optimal distal pathway show that the third protonation step(*NNH_(2)→*NNH_(3))is the rate-determining step and that the increase in oxygen vacancies in the high-entropy perovskite contributes to nitrogen adsorption and reduction.This work provides a framework for applying high-entropy structures with active site diversity for electrocatalytic nitrogen fixation.
