Fabrication of single-crystalline metal-organic framework(MOF)hollow nanostructures with two-dimensional(2D)morphologies is a challenging task.Herein,twin-like MOF nanobricks,a quasi-hollow 2D architecture,with multi-...Fabrication of single-crystalline metal-organic framework(MOF)hollow nanostructures with two-dimensional(2D)morphologies is a challenging task.Herein,twin-like MOF nanobricks,a quasi-hollow 2D architecture,with multi-metal nodes and replaceable organic ligands,are uniformly and firmly grown on conductive Ni foam through a generic one-pot approach.The formation process of twin-like MOF nanobricks mainly includes selective epitaxial growth of Fe-rich MOF layer and simultaneously dissolution of the pre-formed Ni-rich metal-organic frameworks(MOFs),all of which can be ascribed to a special self-templated mechanism.The fantastic structural merits of twin-like MOF nanobrick arrays,featuring highly exposed active sites,remarkable electrical conductivity,and hierarchical porosities,enable this material for efficient electrocatalysis.Using bimetallic NiFe-MOFs grown on Ni foam as an example,the resultant twin-like nanobrick arrays can be directly utilized as three-dimensional(3D)integrated electrode for high-performance water oxidation in 1 M KOH with a low overpotential,fast reaction kinetics(28.5 mV·dec^(-1)),and superb stability.Interestingly,the unstable NiFe-MOFs were served as an oxygen evolution reaction(OER)pre-catalyst and the single-crystalline NiFe-MOF precursor can be in-situ topochemically regulated into porous and lowcrystalline NiFeOx nanosheets during the OER process.This work extends the hollowing strategy to fabricate hollow MOFs with 2D architectures and highlights their direct utilization for advanced electrocatalysis.展开更多
The construction of electrode materials for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)has gradually been an appealing and attractive technology in energy storage research field.In the present work,a fac...The construction of electrode materials for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)has gradually been an appealing and attractive technology in energy storage research field.In the present work,a facile strategy of synthesizing ultrathin amorphous/nanocrystal dual-phase P-doped Bi_(2)MoO_(6)(denoted as P-BiMO)nanosheets via a one-step wet-chemical synthesis approach is explored.Quite distinct from conventional two-dimensional(2D)nanosheets,our newly developed ultrathin P-BiMO nanosheets exhibit a unique tunable amorphous/nanocrystalline dual-phase structure with several compelling advantages including fast ion exchange ability and superb volume change buffer capability.The experimental results reveal that our prepared P-BiMO-6 electrode delivers an excellent reversible capacity of 509.6 mA·g^(−1) after continuous 1,500 cycles at the current densities of 1,500 mA·g^(−1) and improved rate performance for LIBs.In the meanwhile,the P-BiMO-6 electrode also shows a reversible capacity of 300.6 mA·g^(−1) after 100 cycles at 50 mA·g^(−1) when being used as the SIBs electrodes.This present work uncovers an effective dual-phase nanosheet structure to improve the performance of batteries,providing an attractive paradigm to develop superior electrode materials.展开更多
Biomaterials,often imparted time-dependent mechanical properties,which are promising in fields rang-ing from sensors to robotics.Here,a facile method was proposed to fabricate post-tunable mechanical properties compos...Biomaterials,often imparted time-dependent mechanical properties,which are promising in fields rang-ing from sensors to robotics.Here,a facile method was proposed to fabricate post-tunable mechanical properties composites based on hydrogels and ceramic nanofiller.The wide tunable range of Young’s modulus(27.3 kPa to 3.5 GPa)and ultimate stress(173 kPa to 102 MPa)can be achieved by combining solvent absorption and evaporation process with platelets reinforcement effect.Additionally,a large fracture toughness(∼32,000 J m^(-2))is obtained as a result of the nacre-liked“brick and mortar”structure introduced by shear force during fabrication.The superior flexibility and designability of this material were demonstrated via actuators,portable structure,and metamaterials.Above all,this study provides a new thought to fabricate tough materials with post-tunable mechanical properties.展开更多
基金This work was jointly supported by Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone Shenzhen Park Project(No.HZQB-KCZYB-2020030)the National Key R&D Program of China(Project No.2017YFA0204403)Innovation and Technology Commission of HKSAR through Hong Kong Branch of National Precious Metals Material Engineering Research Centre and Shenzhen Science and Technology Innovation Committee(No.JCYJ20200109113212238).
文摘Fabrication of single-crystalline metal-organic framework(MOF)hollow nanostructures with two-dimensional(2D)morphologies is a challenging task.Herein,twin-like MOF nanobricks,a quasi-hollow 2D architecture,with multi-metal nodes and replaceable organic ligands,are uniformly and firmly grown on conductive Ni foam through a generic one-pot approach.The formation process of twin-like MOF nanobricks mainly includes selective epitaxial growth of Fe-rich MOF layer and simultaneously dissolution of the pre-formed Ni-rich metal-organic frameworks(MOFs),all of which can be ascribed to a special self-templated mechanism.The fantastic structural merits of twin-like MOF nanobrick arrays,featuring highly exposed active sites,remarkable electrical conductivity,and hierarchical porosities,enable this material for efficient electrocatalysis.Using bimetallic NiFe-MOFs grown on Ni foam as an example,the resultant twin-like nanobrick arrays can be directly utilized as three-dimensional(3D)integrated electrode for high-performance water oxidation in 1 M KOH with a low overpotential,fast reaction kinetics(28.5 mV·dec^(-1)),and superb stability.Interestingly,the unstable NiFe-MOFs were served as an oxygen evolution reaction(OER)pre-catalyst and the single-crystalline NiFe-MOF precursor can be in-situ topochemically regulated into porous and lowcrystalline NiFeOx nanosheets during the OER process.This work extends the hollowing strategy to fabricate hollow MOFs with 2D architectures and highlights their direct utilization for advanced electrocatalysis.
基金supported by Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone Shenzhen Park Project:HZQB-KCZYB-2020030the National Key R&D Program of China(Project No.2017YFA0204403)Hong Kong Innovation and Technology Commission via the Hong Kong Branch of National Precious Metals Material Engineering Research Center.
文摘The construction of electrode materials for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)has gradually been an appealing and attractive technology in energy storage research field.In the present work,a facile strategy of synthesizing ultrathin amorphous/nanocrystal dual-phase P-doped Bi_(2)MoO_(6)(denoted as P-BiMO)nanosheets via a one-step wet-chemical synthesis approach is explored.Quite distinct from conventional two-dimensional(2D)nanosheets,our newly developed ultrathin P-BiMO nanosheets exhibit a unique tunable amorphous/nanocrystalline dual-phase structure with several compelling advantages including fast ion exchange ability and superb volume change buffer capability.The experimental results reveal that our prepared P-BiMO-6 electrode delivers an excellent reversible capacity of 509.6 mA·g^(−1) after continuous 1,500 cycles at the current densities of 1,500 mA·g^(−1) and improved rate performance for LIBs.In the meanwhile,the P-BiMO-6 electrode also shows a reversible capacity of 300.6 mA·g^(−1) after 100 cycles at 50 mA·g^(−1) when being used as the SIBs electrodes.This present work uncovers an effective dual-phase nanosheet structure to improve the performance of batteries,providing an attractive paradigm to develop superior electrode materials.
基金financial support provided by the Guangdong Provincial Department of Science and Technology (KeyArea Research and Development Program of Guangdong Province) under the grant 2020B090923002Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone Shenzhen Park Project (HZQB-KCZYB-2020030)+2 种基金National Key R&D Program of China (Project No. 2017YFA0204403)the Hong Kong Innovation and Technology Commission via the Hong Kong Branch of National Precious Metals Material Engineering Research Centerthe JLFS-RGC-joint Laboratory Funding Scheme (Reference No. JLFS/E103/18)
文摘Biomaterials,often imparted time-dependent mechanical properties,which are promising in fields rang-ing from sensors to robotics.Here,a facile method was proposed to fabricate post-tunable mechanical properties composites based on hydrogels and ceramic nanofiller.The wide tunable range of Young’s modulus(27.3 kPa to 3.5 GPa)and ultimate stress(173 kPa to 102 MPa)can be achieved by combining solvent absorption and evaporation process with platelets reinforcement effect.Additionally,a large fracture toughness(∼32,000 J m^(-2))is obtained as a result of the nacre-liked“brick and mortar”structure introduced by shear force during fabrication.The superior flexibility and designability of this material were demonstrated via actuators,portable structure,and metamaterials.Above all,this study provides a new thought to fabricate tough materials with post-tunable mechanical properties.