Electrocatalytic synthesis under mild conditions has become increasingly important as one of the practical alternatives for industrial applications,especially for the green ammonia(NH_(3))industry.A properly engineere...Electrocatalytic synthesis under mild conditions has become increasingly important as one of the practical alternatives for industrial applications,especially for the green ammonia(NH_(3))industry.A properly engineered electrocatalyst plays a vital role in the realization of superior catalytic performance.Among various types of promising nanomaterials,metal–organic frameworks(MOFs)are competitive candidates for developing efficient electrocatalytic NH_(3) synthesis from simple nitrogen-containing molecules or ions,such as N_(2) and NO_(3)^(−).In this review,recent advances in the development of electrocatalysts derived from MOFs for the electrosynthesis of NH_(3) are collected,categorized,and discussed,including their application in the N_(2) reduction reaction(NRR)and the NO_(3)^(−)reduction reaction(NO3RR).Firstly,the fundamental principles are illustrated,such as plausible mechanisms of NH_(3) generation from N_(2) and NO_(3)^(−),the apparatus of corresponding electrocatalysis,parameters for evaluation of reaction efficiency,and detection methods of yielding NH_(3).Then,the electrocatalysts for NRR processes are discussed in detail,including pristine MOFs,MOF-hybrids,MOF-derived N-doped porous carbons,single atomic catalysts from pyrolysis of MOFs,and other MOF-related materials.Subsequently,MOF-related NO3RR processes are also listed and discussed.Finally,the existing challenges and prospects for the rational design and fabrication of electrocatalysts from MOFs for electrochemical NH_(3) synthesis are presented,such as the evolution of investigation methods with artificial intelligence,innovation in synthetic methods of MOF-related catalysts,advancement of characterization techniques,and extended electrocatalytic reactions.展开更多
Nano Research volume 13,pages2289–2298(2020)Cite this article 347 Accesses 1 Altmetric Metrics details Abstract Sodium-ion batteries(SIBs)are promising power sources due to the low cost and abundance of battery-grade...Nano Research volume 13,pages2289–2298(2020)Cite this article 347 Accesses 1 Altmetric Metrics details Abstract Sodium-ion batteries(SIBs)are promising power sources due to the low cost and abundance of battery-grade sodium resources,while practical SIBs suffer from intrinsically sluggish diffusion kinetics and severe volume changes of electrode materials.Metal-organic framework(MOFs)derived carbonaceous metal compound offer promising applications in electrode materials due to their tailorable composition,nanostructure,chemical and physical properties.Here,we fabricated hierarchical MOF-derived carbonaceous nickel selenides with bi-phase composition for enhanced sodium storage capability.As MOF formation time increases,the pyrolyzed and selenized products gradually transform from a single-phase Ni3Se4 into bi-phase NiSex then single-phase NiSe2,with concomitant morphological evolution from solid spheres into hierarchical urchin-like yolk-shell structures.As SIBs anodes,bi-phase NiSex@C/CNT-10h(10 h of hydrothermal synthesis time)exhibits a high specific capacity of 387.1 mAh/g at 0.1 A/g,long cycling stability of 306.3 mAh/g at a moderately high current density of 1 A/g after 2,000 cycles.Computational simulation further proves the lattice mismatch at the phase boundary facilitates more interstitial space for sodium storage.Our understanding of the phase boundary engineering of transformed MOFs and their morphological evolution is conducive to fabricate novel composites/hybrids for applications in batteries,catalysis,sensors,and environmental remediation.展开更多
CONSPECTUS:There is an extensive history of research on both inorganic and hybrid metal halides,with the latter being first reported in the 1960s.Although work on hybrid systems has progressed steadily over the last 6...CONSPECTUS:There is an extensive history of research on both inorganic and hybrid metal halides,with the latter being first reported in the 1960s.Although work on hybrid systems has progressed steadily over the last 60 years,it has enjoyed a major renaissance during the last 5 years.This has arisen as a consequence of the 2009 discovery of the outstanding optoelectronic properties of hybrid lead halides,such as(MA)PbI_(3)(MA=methylammonium),and the recognition that there are many opportunities for equally exciting discoveries with compounds of the transition metals.Some of the early work on hybrid transition-metal halides put more emphasis on crystal structures but less on properties.In the modern era,we aim to grasp both the structure and properties,with a new twist.In this Account,we shall explore the recent developments in hybrid transition-metal halides with a focus on work in four main areas:magnetism,photoluminescence,semiconductivity,and spintronics.Our work on magnetism centers on the Ru-based hybrid halides,where the structural types are diversely composed of vacancy-ordered double perovskite,as well as chain-like one-dimensional structures and layered double perovskite(LDP)when paired with a(1+)metal.We explore their magnetic properties and find that their spin−orbit coupling(SOC)behavior can be tuned through changing the A cation and the halide.In the luminescence section,we focus on our recent works on hybrid tetrahedral Mn(II)bromides and Cu(I)and Ag(I)iodides.We correlated our newly discovered 0D A_(m)MnBr_(4)(A=organic cation,m=1 or 2)compounds with previous reports,and generated a trend where the photoluminescence quantum yield(PLQY)increases with larger Mn−Mn distances.The flexible organic cation becomes the most important tool here to tune the structure−PLQY relations.Cu(I)and Ag(I)iodides coordinated with iodides and organic ligands produce new crystal structures with intense PL.For the semiconducting properties,we explore the Pt-based vacancy-ordered double perovskite and hybrid bismuth and indium-based LDPs to show the structural evolution with different choices for the organic cation,the metal and the halide;these have a strong influence on the optical properties.The LDPs specifically exhibit high structure tunability,with a wide range of(1+)and(3+)metal choices,and are exempt from some of the limitations of 3D double perovskite.In the last section,we introduce the recent progress on hybrid transition-metal-based ferroelectrics and spintronic materials.We successfully demonstrate the utilization of chiral Cu(II)chlorides for circularly polarized light(CPL)detection,showing the high anisotropy of the photoresponsivity.We also highlight the work that the authors have contributed in these areas and suggest several exciting opportunities for future developments.展开更多
Graphene is of great interest because of its exciting properties and potential applications,but its production on a large-scale still presents considerable challenges.Herein,we report the synthesis of predominately fe...Graphene is of great interest because of its exciting properties and potential applications,but its production on a large-scale still presents considerable challenges.Herein,we report the synthesis of predominately few-layer graphene,due toπ–πstacking,and single-layer graphene from reaction between hexabromobenzene and Na metal,followed by annealing to improve crystallinity.The reaction proceeds via a free-radical C(sp^(2))–C(sp^(2))coupling mechanism,which is supported by theoretical calculations.The graphene can host unpaired spin electrons,leading to a short acquisition time for a solidstate nuclear magnetic resonance 13C spectrum from unlabeled graphene,which is ascribed to the very short spin-lattice relaxation time.High catalytic activity for transforming amine to imine with a conversion of>99%and a yield of∼97%is demonstrated,and high electronic conductivity of∼105 S·m^(−1) is found by terahertz spectroscopy.The reaction delivers a method for synthesizing graphene with a high spin concentration from perbrominated benzene molecules by using an active metallic agent,such as Na,Li,or Mg.展开更多
基金support from the Natural Science Foundation of Liaoning Province(general program)(2020-MS-137)T.J.White would like to thank the MOE2019-T2-2-032 grant and Monetary Academic Resources for Research Grant 001561-00001 in Nanyang Technological University,Singapore+9 种基金T.Ma would like to thank the National Natural Science Foundation of China(Nos.52071171,52202248)Liaoning BaiQianWan Talents Program(LNBQW2018B0048)Shenyang Science and Technology Project(21-108-9-04)Australian Research Council(ARC)through Future Fellowship(FT210100298,FT210100806)Discovery Project(DP220100603)Linkage Project(LP210100467,LP210200504,LP210200345,LP220100088)Industrial Transformation Training Centre(IC180100005)schemesthe Australian Government through the Cooperative Research Centres Projects(CRCPXIII000077)F.Wei would like to thank the A^(*)STAR career development fund C210112054Singapore structural metal alloy program grant No.A18b1B0061.A.K.Cheetham would like to thank the Ras al Khaimah Centre for Advanced Materials.
文摘Electrocatalytic synthesis under mild conditions has become increasingly important as one of the practical alternatives for industrial applications,especially for the green ammonia(NH_(3))industry.A properly engineered electrocatalyst plays a vital role in the realization of superior catalytic performance.Among various types of promising nanomaterials,metal–organic frameworks(MOFs)are competitive candidates for developing efficient electrocatalytic NH_(3) synthesis from simple nitrogen-containing molecules or ions,such as N_(2) and NO_(3)^(−).In this review,recent advances in the development of electrocatalysts derived from MOFs for the electrosynthesis of NH_(3) are collected,categorized,and discussed,including their application in the N_(2) reduction reaction(NRR)and the NO_(3)^(−)reduction reaction(NO3RR).Firstly,the fundamental principles are illustrated,such as plausible mechanisms of NH_(3) generation from N_(2) and NO_(3)^(−),the apparatus of corresponding electrocatalysis,parameters for evaluation of reaction efficiency,and detection methods of yielding NH_(3).Then,the electrocatalysts for NRR processes are discussed in detail,including pristine MOFs,MOF-hybrids,MOF-derived N-doped porous carbons,single atomic catalysts from pyrolysis of MOFs,and other MOF-related materials.Subsequently,MOF-related NO3RR processes are also listed and discussed.Finally,the existing challenges and prospects for the rational design and fabrication of electrocatalysts from MOFs for electrochemical NH_(3) synthesis are presented,such as the evolution of investigation methods with artificial intelligence,innovation in synthetic methods of MOF-related catalysts,advancement of characterization techniques,and extended electrocatalytic reactions.
基金This research was supported by the National Natural Science Foundation of China(No.51773165)Project of National Defense Science and Technology Innovation Special Zone(No.JZ-20171102)+3 种基金Shaanxi Post-doctoral Foundation(No.2016BSHYDZZ20)Key Laboratory Construction Program of Xi’an Municipal Bureau of Science and Technology(No.201805056ZD7CG40)Innovation Capability Support Program of Shaanxi(No.2018PT-28,2019PT-05)The numerical calculations in this paper have been done on the supercomputing system in the Supercomputing Center of Wuhan University.A.K.C.thanks the Ras al Khaimah Centre for Advanced Materials for financial support.J.H.thanks the financial support(No.DE190100803)。
文摘Nano Research volume 13,pages2289–2298(2020)Cite this article 347 Accesses 1 Altmetric Metrics details Abstract Sodium-ion batteries(SIBs)are promising power sources due to the low cost and abundance of battery-grade sodium resources,while practical SIBs suffer from intrinsically sluggish diffusion kinetics and severe volume changes of electrode materials.Metal-organic framework(MOFs)derived carbonaceous metal compound offer promising applications in electrode materials due to their tailorable composition,nanostructure,chemical and physical properties.Here,we fabricated hierarchical MOF-derived carbonaceous nickel selenides with bi-phase composition for enhanced sodium storage capability.As MOF formation time increases,the pyrolyzed and selenized products gradually transform from a single-phase Ni3Se4 into bi-phase NiSex then single-phase NiSe2,with concomitant morphological evolution from solid spheres into hierarchical urchin-like yolk-shell structures.As SIBs anodes,bi-phase NiSex@C/CNT-10h(10 h of hydrothermal synthesis time)exhibits a high specific capacity of 387.1 mAh/g at 0.1 A/g,long cycling stability of 306.3 mAh/g at a moderately high current density of 1 A/g after 2,000 cycles.Computational simulation further proves the lattice mismatch at the phase boundary facilitates more interstitial space for sodium storage.Our understanding of the phase boundary engineering of transformed MOFs and their morphological evolution is conducive to fabricate novel composites/hybrids for applications in batteries,catalysis,sensors,and environmental remediation.
基金The work highlighted in this Account was supported by the Department of Energy,Office of Science,Basic Energy Sciences,under Grant No.SC0012541.L.M.thanks the SUSTech startup grant(Y01216150)P.V.thanks the Science&Engineering Research Board(SERB)of the Govt.of India for the Ramanujan Fellowship(Award No.RJF/2020/000106)the Jawaharlal Nehru Centre for Advanced Scientific Research(JNCASR)Bangalore for the financial support and the research infrastructure.
文摘CONSPECTUS:There is an extensive history of research on both inorganic and hybrid metal halides,with the latter being first reported in the 1960s.Although work on hybrid systems has progressed steadily over the last 60 years,it has enjoyed a major renaissance during the last 5 years.This has arisen as a consequence of the 2009 discovery of the outstanding optoelectronic properties of hybrid lead halides,such as(MA)PbI_(3)(MA=methylammonium),and the recognition that there are many opportunities for equally exciting discoveries with compounds of the transition metals.Some of the early work on hybrid transition-metal halides put more emphasis on crystal structures but less on properties.In the modern era,we aim to grasp both the structure and properties,with a new twist.In this Account,we shall explore the recent developments in hybrid transition-metal halides with a focus on work in four main areas:magnetism,photoluminescence,semiconductivity,and spintronics.Our work on magnetism centers on the Ru-based hybrid halides,where the structural types are diversely composed of vacancy-ordered double perovskite,as well as chain-like one-dimensional structures and layered double perovskite(LDP)when paired with a(1+)metal.We explore their magnetic properties and find that their spin−orbit coupling(SOC)behavior can be tuned through changing the A cation and the halide.In the luminescence section,we focus on our recent works on hybrid tetrahedral Mn(II)bromides and Cu(I)and Ag(I)iodides.We correlated our newly discovered 0D A_(m)MnBr_(4)(A=organic cation,m=1 or 2)compounds with previous reports,and generated a trend where the photoluminescence quantum yield(PLQY)increases with larger Mn−Mn distances.The flexible organic cation becomes the most important tool here to tune the structure−PLQY relations.Cu(I)and Ag(I)iodides coordinated with iodides and organic ligands produce new crystal structures with intense PL.For the semiconducting properties,we explore the Pt-based vacancy-ordered double perovskite and hybrid bismuth and indium-based LDPs to show the structural evolution with different choices for the organic cation,the metal and the halide;these have a strong influence on the optical properties.The LDPs specifically exhibit high structure tunability,with a wide range of(1+)and(3+)metal choices,and are exempt from some of the limitations of 3D double perovskite.In the last section,we introduce the recent progress on hybrid transition-metal-based ferroelectrics and spintronic materials.We successfully demonstrate the utilization of chiral Cu(II)chlorides for circularly polarized light(CPL)detection,showing the high anisotropy of the photoresponsivity.We also highlight the work that the authors have contributed in these areas and suggest several exciting opportunities for future developments.
基金This work was financially support from the National Key R&D Program of China(no.2016YFA0200200)the National Program on Key Basic Research Project(973 program,no.2013CB933804)+1 种基金the National Natural Science Foundation of China(no.21271112)the Tribology Science Fund of State Key Laboratory of Tribology(SKLTKF20B18).
文摘Graphene is of great interest because of its exciting properties and potential applications,but its production on a large-scale still presents considerable challenges.Herein,we report the synthesis of predominately few-layer graphene,due toπ–πstacking,and single-layer graphene from reaction between hexabromobenzene and Na metal,followed by annealing to improve crystallinity.The reaction proceeds via a free-radical C(sp^(2))–C(sp^(2))coupling mechanism,which is supported by theoretical calculations.The graphene can host unpaired spin electrons,leading to a short acquisition time for a solidstate nuclear magnetic resonance 13C spectrum from unlabeled graphene,which is ascribed to the very short spin-lattice relaxation time.High catalytic activity for transforming amine to imine with a conversion of>99%and a yield of∼97%is demonstrated,and high electronic conductivity of∼105 S·m^(−1) is found by terahertz spectroscopy.The reaction delivers a method for synthesizing graphene with a high spin concentration from perbrominated benzene molecules by using an active metallic agent,such as Na,Li,or Mg.
