The development of highly efficient Pt-based alloy nanocatalysts is important but remains challenging for fuel cells commercialization.Here,a new class of zigzag-like platinum-zinc (Pt-Zn) alloy nanowires (NWs) with r...The development of highly efficient Pt-based alloy nanocatalysts is important but remains challenging for fuel cells commercialization.Here,a new class of zigzag-like platinum-zinc (Pt-Zn) alloy nanowires (NWs) with rough surface and controllable composition is reported.The merits of anisotropic one-dimensional nanostructure,stable high-index facets and coordinatively unsaturated Pt sites endow the composition-optimal Pt94Zn6 NWs with a mass activity of 7.2 and 6.2 times higher than that of commercial Pt black catalysts toward methanol/ethanol oxidation,respectively.Alloying-induced d-band electron modulation and lattice strain effects weaken the adsorption strength of poisoning species,which originally enhances the catalytic activity of Pt-Zn NWs.This study provides a new perspective of Pt-Zn electrocatalysts with intrinsic mechanism for enhanced catalytic performance.展开更多
Two-dimensional(2D)transition metal carbides(MXene)possess attractive conductivity and abundant surface functional groups,providing immense potential in the field of electromagnetic wave(EMW)absorption.However,high co...Two-dimensional(2D)transition metal carbides(MXene)possess attractive conductivity and abundant surface functional groups,providing immense potential in the field of electromagnetic wave(EMW)absorption.However,high conductivity and spontaneous aggregation of MXene suffer from limited EMW response.Inspired by dielectric–magnetic synergy effect,the strategy of decorating MXene with magnetic elements is expected to solve this challenge.In this work,zigzag-like Mo_(2)TiC_(2)–MXene nanofibers(Mo-based MXene(Mo–MXene)NFs)with cross-linked networks are fabricated by hydrofluoric acid(HF)etching and potassium hydroxide(KOH)shearing processes.Subsequently,Co-metal–organic framework(MOF)and derived CoNi layered double hydroxide(LDH)ultrathin nanosheets are grown inside Mo–MXene NFs,and the N-doped carbon matrix anchored by CoNi alloy nanoparticles formed by pyrolysis is firmly embedded in the Mo–MXene NFs network.Benefiting from synergistic effect of highly dispersed small CoNi alloy nanoparticles,a three-dimensional(3D)conductive network assembled by zigzag-like Mo–MXene NFs,numerous N-doped hollow carbon vesicles,and abundant dual heterogeneous interface,the designed Mo–MXene/CoNi–NC heterostructure provides robust EMW absorption ability with a reflection loss(RL)value of−68.45 dB at the thickness(d)of 4.38 mm.The robust EMW absorption performance can be attributed to excellent dielectric loss,magnetic loss,impedance matching(Z),and multiple scattering and reflection triggered by the unique 3D network structure.This work puts up great potential in developing advanced MXene-based EMW absorption devices.展开更多
A new cerium polyoxomolybdate { [Ce （ H2 O） 7 Al （ OH ） 6 Mo6 O18 ] · 4H20 } （ compound 1 ） was synthesized and characterized by X-ray diffraction analysis, elemental analysis, TG analysis and IR spectromet...A new cerium polyoxomolybdate { [Ce （ H2 O） 7 Al （ OH ） 6 Mo6 O18 ] · 4H20 } （ compound 1 ） was synthesized and characterized by X-ray diffraction analysis, elemental analysis, TG analysis and IR spectrometry. Compound 1 exhibits a zigzag chain-like structure, which is constructed from an Anderson type anion and rare earth metal, Ce（ Ⅲ ）. These 1-D chains are further extended into a 3-D network by the aid of muhipoint hydrogen-bonding interactions.展开更多
基金the National Key Research and Development Program of China (No.2016YFA0200400)the National Natural Science Foundation of China (Nos.51571100,51602305, 51522212,51421002,and 51672307)+1 种基金Program for JLU Science and Technology Innovative Research Team (JLUSTIRT,2017TD-09)the Fundamental Research Funds for the Central Universities and the Graduate Innovation Fund of Jilin University.
文摘The development of highly efficient Pt-based alloy nanocatalysts is important but remains challenging for fuel cells commercialization.Here,a new class of zigzag-like platinum-zinc (Pt-Zn) alloy nanowires (NWs) with rough surface and controllable composition is reported.The merits of anisotropic one-dimensional nanostructure,stable high-index facets and coordinatively unsaturated Pt sites endow the composition-optimal Pt94Zn6 NWs with a mass activity of 7.2 and 6.2 times higher than that of commercial Pt black catalysts toward methanol/ethanol oxidation,respectively.Alloying-induced d-band electron modulation and lattice strain effects weaken the adsorption strength of poisoning species,which originally enhances the catalytic activity of Pt-Zn NWs.This study provides a new perspective of Pt-Zn electrocatalysts with intrinsic mechanism for enhanced catalytic performance.
基金This work was supported by the National Natural Science Foundation of China(No.22269010)the Jiangxi Provincial Natural Science Foundation(No.20224BAB214021)+3 种基金the Training Program for Academic and Technical Leaders of Major Disciplines in Jiangxi Province(No.20212BCJ23020)the Science and Technology Project of Jiangxi Provincial Department of Education(No.GJJ211305)the National Natural Science Foundation of China(No.U2004177)the Outstanding Youth Fund of Henan Province(No.212300410081).
文摘Two-dimensional(2D)transition metal carbides(MXene)possess attractive conductivity and abundant surface functional groups,providing immense potential in the field of electromagnetic wave(EMW)absorption.However,high conductivity and spontaneous aggregation of MXene suffer from limited EMW response.Inspired by dielectric–magnetic synergy effect,the strategy of decorating MXene with magnetic elements is expected to solve this challenge.In this work,zigzag-like Mo_(2)TiC_(2)–MXene nanofibers(Mo-based MXene(Mo–MXene)NFs)with cross-linked networks are fabricated by hydrofluoric acid(HF)etching and potassium hydroxide(KOH)shearing processes.Subsequently,Co-metal–organic framework(MOF)and derived CoNi layered double hydroxide(LDH)ultrathin nanosheets are grown inside Mo–MXene NFs,and the N-doped carbon matrix anchored by CoNi alloy nanoparticles formed by pyrolysis is firmly embedded in the Mo–MXene NFs network.Benefiting from synergistic effect of highly dispersed small CoNi alloy nanoparticles,a three-dimensional(3D)conductive network assembled by zigzag-like Mo–MXene NFs,numerous N-doped hollow carbon vesicles,and abundant dual heterogeneous interface,the designed Mo–MXene/CoNi–NC heterostructure provides robust EMW absorption ability with a reflection loss(RL)value of−68.45 dB at the thickness(d)of 4.38 mm.The robust EMW absorption performance can be attributed to excellent dielectric loss,magnetic loss,impedance matching(Z),and multiple scattering and reflection triggered by the unique 3D network structure.This work puts up great potential in developing advanced MXene-based EMW absorption devices.
文摘A new cerium polyoxomolybdate { [Ce （ H2 O） 7 Al （ OH ） 6 Mo6 O18 ] · 4H20 } （ compound 1 ） was synthesized and characterized by X-ray diffraction analysis, elemental analysis, TG analysis and IR spectrometry. Compound 1 exhibits a zigzag chain-like structure, which is constructed from an Anderson type anion and rare earth metal, Ce（ Ⅲ ）. These 1-D chains are further extended into a 3-D network by the aid of muhipoint hydrogen-bonding interactions.
