Metal–organic frameworks(MOFs)with redox-active metal sites and controllable crystalline structures make it possible to access the merits of highly-efficient electrode materials in electrochemical energy storage syst...Metal–organic frameworks(MOFs)with redox-active metal sites and controllable crystalline structures make it possible to access the merits of highly-efficient electrode materials in electrochemical energy storage systems.However,most MOFs suffer from low capacitance and poor cycling stability that largely thwart their application.Herein,we present the holey graphene oxide(HGO)template strategy to prepare nano two-dimensional Ni(BDC)with HGO as both template and capping agent(denoted as Ni(BDC)-HGOx,x=10,20,30,and 40 according to the added HGO amount).Structural analyses reveal that HGO can significantly inhibit the Ni(BDC)agglomeration,thus offering a high ion-accessible surface area.Ni(BDC)-HGO30 with well-exposed active sites exhibits a high capacitance of 1,115.6 F·g^(−1) at 1 A·g^(−1) in 6 M KOH aqueous,1.8 times that of bulk Ni(BDC).An asymmetric supercapacitor with Ni(BDC)-HGO30 as a positive electrode and activated carbon as the opposing electrode delivers an energy density of 52.5 W·h·kg^(−1) and a power density up to 18.0 kW·kg−1,with 92.5%capacitance retention after 10,000 cycles.Galvanostatic intermittent titration technique and in situ electrochemical–Raman measurements were exploited to elucidate the electrochemical behavior of Ni(BDC)-HGO30.These results pave the way for the development of rationally tuned MOF materials for enhancing supercapacitor performances.展开更多
The development of the rapid preparation of highly stable metal-organic framework(MOF)-based devices provides the possibility of meeting the increasing demands of MOF in industrial applications.However,MOFs experience...The development of the rapid preparation of highly stable metal-organic framework(MOF)-based devices provides the possibility of meeting the increasing demands of MOF in industrial applications.However,MOFs experience poor processability and stable high-valence-metal(Ⅳ)-based MOFs favor forming either thermodynamically stable metal hydroxides or oxides during their growth and nucleation,which hinders their practical applications.Herein,we present a versatile deep eutectic solvent(DES)-assisted hot pressing method to in situ rapidly prepare six distinct zirconium-based MOF nanocrystals on fibers(denoted as Zr-MOFilters)within 20 min.A small amount of DES promotes MOF precursor contact and accelerates Zr-MOF growth.Temperature and pressure facilitate the formation of Zr-MOFs onto desired substrates.In situ1H nuclear magnetic resonance spectra and time-dependent Fourier-transform infrared spectra were conducted to elucidate the growth of Zr-MOF nanocrystals.As a proof-of-concept,the abilities of Zr-MOFilters for Cr_(2)O_(7)^(2−) and micro(nano)plastics removal have been demonstrated.This strategy paves the way for the rapid fabrication of highly stable MOF-based devices and brings MOFs a step closer to practical application.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22105226 and 51972342)the Shandong Province Postdoctoral Innovative Talent Support Program(No.SDBX20200004)+3 种基金the China Postdoctoral Science Foundation(No.2020M682253)the Qingdao Postdoctoral Funding Project(No.ZX20210067)he Independent innovation scientific research project(No.20CX06100A)the Taishan Scholar Project of Shandong Province(No.ts20190922).
文摘Metal–organic frameworks(MOFs)with redox-active metal sites and controllable crystalline structures make it possible to access the merits of highly-efficient electrode materials in electrochemical energy storage systems.However,most MOFs suffer from low capacitance and poor cycling stability that largely thwart their application.Herein,we present the holey graphene oxide(HGO)template strategy to prepare nano two-dimensional Ni(BDC)with HGO as both template and capping agent(denoted as Ni(BDC)-HGOx,x=10,20,30,and 40 according to the added HGO amount).Structural analyses reveal that HGO can significantly inhibit the Ni(BDC)agglomeration,thus offering a high ion-accessible surface area.Ni(BDC)-HGO30 with well-exposed active sites exhibits a high capacitance of 1,115.6 F·g^(−1) at 1 A·g^(−1) in 6 M KOH aqueous,1.8 times that of bulk Ni(BDC).An asymmetric supercapacitor with Ni(BDC)-HGO30 as a positive electrode and activated carbon as the opposing electrode delivers an energy density of 52.5 W·h·kg^(−1) and a power density up to 18.0 kW·kg−1,with 92.5%capacitance retention after 10,000 cycles.Galvanostatic intermittent titration technique and in situ electrochemical–Raman measurements were exploited to elucidate the electrochemical behavior of Ni(BDC)-HGO30.These results pave the way for the development of rationally tuned MOF materials for enhancing supercapacitor performances.
基金supported by the National Natural Science Foundation of China(22105226,51972342,51972345,22171287)Shandong Province Postdoctoral Innovative Talent Support Program(SDBX20200004)+4 种基金the China Postdoctoral Science Foundation(2020M682253)Qingdao Postdoctoral Funding Project(ZX20210067)the Independent Innovation Scientific Research Project(20CX06100A,21CX06002A)Taishan Scholar Project of Shandong Province(ts20190922,tsqn202103046)the Natural Science Foundation of Shanxi Province(20210302123325)。
文摘The development of the rapid preparation of highly stable metal-organic framework(MOF)-based devices provides the possibility of meeting the increasing demands of MOF in industrial applications.However,MOFs experience poor processability and stable high-valence-metal(Ⅳ)-based MOFs favor forming either thermodynamically stable metal hydroxides or oxides during their growth and nucleation,which hinders their practical applications.Herein,we present a versatile deep eutectic solvent(DES)-assisted hot pressing method to in situ rapidly prepare six distinct zirconium-based MOF nanocrystals on fibers(denoted as Zr-MOFilters)within 20 min.A small amount of DES promotes MOF precursor contact and accelerates Zr-MOF growth.Temperature and pressure facilitate the formation of Zr-MOFs onto desired substrates.In situ1H nuclear magnetic resonance spectra and time-dependent Fourier-transform infrared spectra were conducted to elucidate the growth of Zr-MOF nanocrystals.As a proof-of-concept,the abilities of Zr-MOFilters for Cr_(2)O_(7)^(2−) and micro(nano)plastics removal have been demonstrated.This strategy paves the way for the rapid fabrication of highly stable MOF-based devices and brings MOFs a step closer to practical application.