A metal-organic framework/inorganic composite(ZIF-8@AMP)was synthesized by the in situ introduction of the active component ammonium phosphomolybdate(AMP)during the ambient solution-phase synthesis of the metal-organi...A metal-organic framework/inorganic composite(ZIF-8@AMP)was synthesized by the in situ introduction of the active component ammonium phosphomolybdate(AMP)during the ambient solution-phase synthesis of the metal-organic framework(ZIF-8).The structure and properties of the composite were characterized using scanning electron microscopy(SEM),X-ray powder diffraction(XRD),X-ray photoelectron spectroscopy(XPS),thermogravimetric analysis(TGA),and Fourier transform infrared spectroscopy(FTIR).Its adsorption performance for Rb^(+)and Cs^(+)in water was investigated.Results indicate that ZIF-8@AMP exhibited adsorption efficiencies of 93.5%and 95.6%for Rb^(+)and Cs^(+)within 30 min,with maximum adsorption capacities of 92.7 and 104.5 mg·g^(-1),respectively.After five adsorption-desorption cycles,it maintained high adsorption capacity and achieved over 84.9%adsorption efficiency for Rb^(+)and Cs^(+)in actual brine samples.The adsorption of ZIF-8@AMP for Rb^(+)and Cs^(+)follows pseudosecond-order kinetics and the Langmuir adsorption isotherm,indicating an endothermic,entropy-increasing,and spontaneous process.The adsorption mechanism involves electrostatic attraction and ion exchange between ZIF-8@AMP and Rb^(+)and Cs^(+).展开更多
Zeolite imidazolate framework(ZIF)-derived bimetallic sulfides and layered double hydroxides(LDHs)have emerged as promising electrode materials for supercapacitors,owing to their porous layered structures,high electro...Zeolite imidazolate framework(ZIF)-derived bimetallic sulfides and layered double hydroxides(LDHs)have emerged as promising electrode materials for supercapacitors,owing to their porous layered structures,high electrochemical activity,tun-able molecular architectures,low cost,and high specific capacitance.In this study,a unique composite material comprising ZIF-derived ZnCo bimetallic sulfide and LDH with a honeycomb-like structure was in situ grown on nickel foil(NF)via a con-trolled self-sacrificial template strategy.In contrast to previous reports,the resulting ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF compos-ite integrates the advantages of MXene,LDH,and sulfides,leading to significantly enhanced conductivity,structural stability,and catalytic activity.The ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF electrode exhibits a uniform network structure with a thickness of approximately 1μm coated on NF,and delivers a high specific capacitance of 1356.1 F·g^(-1)at a current density of 2 A·g^(-1).Further-more,an asymmetric supercapacitor assembled with ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF as the positive electrode and activated car-bon as the negative electrode achieves a high energy density of 34.08 Wh·kg^(-1)and a power density of 742.3 W·kg^(-1)at 1 A·g^(-1).This device successfully powers LED lights for 5 min,demonstrating its practical applicability.These results underscore the out-standing electrochemical performance of the ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF electrode,highlighting its potential for applica-tions in supercapacitors and related energy storage fields.展开更多
Rational design of non-noble electrocatalysts with high performance for oxygen evolution reaction(OER)still remains a challenge.In this study,a ZIF-derived electrocatalyst(Co@Fe-P)with a core-shell structure is design...Rational design of non-noble electrocatalysts with high performance for oxygen evolution reaction(OER)still remains a challenge.In this study,a ZIF-derived electrocatalyst(Co@Fe-P)with a core-shell structure is designed by using Co-compounds as the core and PO_(4)^(3-)decorated Fe-compounds as the shell.The inner Co-core and outer Fe-shell are connected through Co-O-Fe and Fe-O-P linkage.The Co@Fe-P electrocatalyst exhibits an enhanced performance for OER with a low overpotential(280 mV),low Tafel slope(41.9 mV dec^(-1))at 10 mA cm^(-2),and a 60-h durability.The electron transfer from the CoOOH-core to the FeOOH-shell is greatly facilitated,which improves the OER activity of Co@Fe-P kinetically.Theoretical calculations indicate that the interaction of Co-O-Fe and Fe-O-P in Co@Fe-P reduces the overlap between the O 2p and Fe 3d orbitals,which greatly facilitates the transformation from*OH to*O during the OER process via the adsorbate evolution mechanism(AEM)pathway.This finding provides insight for the design of efficient electrocatalysts for OER.展开更多
文摘A metal-organic framework/inorganic composite(ZIF-8@AMP)was synthesized by the in situ introduction of the active component ammonium phosphomolybdate(AMP)during the ambient solution-phase synthesis of the metal-organic framework(ZIF-8).The structure and properties of the composite were characterized using scanning electron microscopy(SEM),X-ray powder diffraction(XRD),X-ray photoelectron spectroscopy(XPS),thermogravimetric analysis(TGA),and Fourier transform infrared spectroscopy(FTIR).Its adsorption performance for Rb^(+)and Cs^(+)in water was investigated.Results indicate that ZIF-8@AMP exhibited adsorption efficiencies of 93.5%and 95.6%for Rb^(+)and Cs^(+)within 30 min,with maximum adsorption capacities of 92.7 and 104.5 mg·g^(-1),respectively.After five adsorption-desorption cycles,it maintained high adsorption capacity and achieved over 84.9%adsorption efficiency for Rb^(+)and Cs^(+)in actual brine samples.The adsorption of ZIF-8@AMP for Rb^(+)and Cs^(+)follows pseudosecond-order kinetics and the Langmuir adsorption isotherm,indicating an endothermic,entropy-increasing,and spontaneous process.The adsorption mechanism involves electrostatic attraction and ion exchange between ZIF-8@AMP and Rb^(+)and Cs^(+).
基金support by NSFC(No.61704047)Natural Science Foundation of Henan Province(No.242300420271)Key Research Project of Henan Provincial Higher Education(No.24A430008).
文摘Zeolite imidazolate framework(ZIF)-derived bimetallic sulfides and layered double hydroxides(LDHs)have emerged as promising electrode materials for supercapacitors,owing to their porous layered structures,high electrochemical activity,tun-able molecular architectures,low cost,and high specific capacitance.In this study,a unique composite material comprising ZIF-derived ZnCo bimetallic sulfide and LDH with a honeycomb-like structure was in situ grown on nickel foil(NF)via a con-trolled self-sacrificial template strategy.In contrast to previous reports,the resulting ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF compos-ite integrates the advantages of MXene,LDH,and sulfides,leading to significantly enhanced conductivity,structural stability,and catalytic activity.The ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF electrode exhibits a uniform network structure with a thickness of approximately 1μm coated on NF,and delivers a high specific capacitance of 1356.1 F·g^(-1)at a current density of 2 A·g^(-1).Further-more,an asymmetric supercapacitor assembled with ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF as the positive electrode and activated car-bon as the negative electrode achieves a high energy density of 34.08 Wh·kg^(-1)and a power density of 742.3 W·kg^(-1)at 1 A·g^(-1).This device successfully powers LED lights for 5 min,demonstrating its practical applicability.These results underscore the out-standing electrochemical performance of the ZnS@Co_(3)S_(4)@MXene@Ni-LDH/NF electrode,highlighting its potential for applica-tions in supercapacitors and related energy storage fields.
基金financially supported by the National Natural Science Foundation of China(Nos.22372143 and 22208281)the Hebei Natural Science Foundation(Nos.B2023203001 and B2025203050)the Science Research Project of Hebei Education Department(BJK2024122)。
文摘Rational design of non-noble electrocatalysts with high performance for oxygen evolution reaction(OER)still remains a challenge.In this study,a ZIF-derived electrocatalyst(Co@Fe-P)with a core-shell structure is designed by using Co-compounds as the core and PO_(4)^(3-)decorated Fe-compounds as the shell.The inner Co-core and outer Fe-shell are connected through Co-O-Fe and Fe-O-P linkage.The Co@Fe-P electrocatalyst exhibits an enhanced performance for OER with a low overpotential(280 mV),low Tafel slope(41.9 mV dec^(-1))at 10 mA cm^(-2),and a 60-h durability.The electron transfer from the CoOOH-core to the FeOOH-shell is greatly facilitated,which improves the OER activity of Co@Fe-P kinetically.Theoretical calculations indicate that the interaction of Co-O-Fe and Fe-O-P in Co@Fe-P reduces the overlap between the O 2p and Fe 3d orbitals,which greatly facilitates the transformation from*OH to*O during the OER process via the adsorbate evolution mechanism(AEM)pathway.This finding provides insight for the design of efficient electrocatalysts for OER.
