To improve lithium-sulfur battery performance,Co-MOF-74 has been applied for the first time as an interlayer with multiwalled carbon nanotubes(MWCNTs).Co-MOF-74@MWCNT was synthesized using a solvothermal method.The fa...To improve lithium-sulfur battery performance,Co-MOF-74 has been applied for the first time as an interlayer with multiwalled carbon nanotubes(MWCNTs).Co-MOF-74@MWCNT was synthesized using a solvothermal method.The fabrication of Co-MOF-74@MWCNT was confirmed by scanning electron microscopy,X-ray diffraction,thermogravimetric analysis,and Brunauer-Emmett-Teller testing.The interlayer was fabricated using a filtration method.Assembled batteries were prepared using a CoMOF-74@MWCNT interlayer and an MWCNT interlayer and subsequently investigated via cyclic voltammetry tests.Co-MOF-74 promotes a redox reaction and shows a small peak at 1.85 V.A symmetric and full cell test revealed that the Co-MOF-74@MWCNT cell enables a faster redox reaction and higher capacity than that of the MWCNT cell.After 15 cycles,the Co-MOF-74@MWCNT cell achieved a value of 1112 mAh g^(-1),which is 26% greater than that of the MWCNT cell(880 mAh g^(-1)) at 0.2 C.Voltage profile testing showed that the reason for the higher capacity of the Co-MOF-74@MWCNT cell is that it promotes the conversion of Li_(2)S_(2) to Li_(2)S.Various electrochemical analyses confirmed that the Co-MOF-74@MWCNT interlayer acts not only as a physical and chemical barrier but also promotes the transformation of Li_(2)S_(2) to Li_(2)S.展开更多
Metal-organic frameworks(MOFs)with porous crystal structures have attracted extensive attention in application of energy storage and conversion,owing to their regularity,porosity,large specific surface area,etc.In thi...Metal-organic frameworks(MOFs)with porous crystal structures have attracted extensive attention in application of energy storage and conversion,owing to their regularity,porosity,large specific surface area,etc.In this work,Co-MOF-74 microflower has been successfully prepared via a controllable solvent regulation strategy.Through modulating the polarity of the solvent,crystals grow in certain preferred orientation and Co-MOF-74 with various morphologies were obtained.Thereinto,the energy storage performance of Co-MOF-74 microflower was measured in both three-electrode system and asymmetric supercapacitor device(specific capacitance of 164.2 F/g at 0.5 A/g in the three-electrode system and 62.5 F/g at 1 A/g in the asymmetric supercapacitor device).This can be attributed to the preferred crystal orientation resulting in a regular and uniform microflower,which is of great significance to electronic interfacial exchange and ion transfer during electrochemical reactions.展开更多
To obtain a cost-effective adsorbent for the removal of arsenic in water,a novel nanostructured Fe–Co based metal organic framework(MOF-74)adsorbent was successfully prepared via a simple solvothermal method.The adso...To obtain a cost-effective adsorbent for the removal of arsenic in water,a novel nanostructured Fe–Co based metal organic framework(MOF-74)adsorbent was successfully prepared via a simple solvothermal method.The adsorption experiments showed that the optimal molar ratio of Fe/Co in the adsorbent was 2:1.The Fe_2Co_1MOF-74 was characterized by various techniques and the results showed that the nanoparticle diameter ranged from60 to 80 nm and the specific surface area was 147.82 m^2/g.The isotherm and kinetic parameters of arsenic removal on Fe_2Co_1MOF-74 were well-fitted by the Langmuir and pseudo-second-order models.The maximum adsorption capacities toward As(III)and As(V)were 266.52 and 292.29 mg/g,respectively.The presence of sulfate,carbonate and humic acid had no obvious effect on arsenic adsorption.However,coexisting phosphate significantly hindered the removal of arsenic,especially at high concentrations(10 mmol/L).Electrostatic interaction and hydroxyl and metal–oxygen groups played important roles in the adsorption of arsenic.Furthermore,the prepared adsorbent had stable adsorption ability after regeneration and when used in a real-water matrix.The excellent adsorption performance of Fe_2Co_1MOF-74 material makes it a potentially promising adsorbent for the removal of arsenic.展开更多
基金supported by grants from the National Research Foundation of Korea (NRF) and the Korean government (MSIT) (2017M3A9E2093907 and 2020R1A2C1012838)。
文摘To improve lithium-sulfur battery performance,Co-MOF-74 has been applied for the first time as an interlayer with multiwalled carbon nanotubes(MWCNTs).Co-MOF-74@MWCNT was synthesized using a solvothermal method.The fabrication of Co-MOF-74@MWCNT was confirmed by scanning electron microscopy,X-ray diffraction,thermogravimetric analysis,and Brunauer-Emmett-Teller testing.The interlayer was fabricated using a filtration method.Assembled batteries were prepared using a CoMOF-74@MWCNT interlayer and an MWCNT interlayer and subsequently investigated via cyclic voltammetry tests.Co-MOF-74 promotes a redox reaction and shows a small peak at 1.85 V.A symmetric and full cell test revealed that the Co-MOF-74@MWCNT cell enables a faster redox reaction and higher capacity than that of the MWCNT cell.After 15 cycles,the Co-MOF-74@MWCNT cell achieved a value of 1112 mAh g^(-1),which is 26% greater than that of the MWCNT cell(880 mAh g^(-1)) at 0.2 C.Voltage profile testing showed that the reason for the higher capacity of the Co-MOF-74@MWCNT cell is that it promotes the conversion of Li_(2)S_(2) to Li_(2)S.Various electrochemical analyses confirmed that the Co-MOF-74@MWCNT interlayer acts not only as a physical and chemical barrier but also promotes the transformation of Li_(2)S_(2) to Li_(2)S.
基金supported by the National Natural Science Foundation of China(Nos.U1904215,21671170,21673203)the Topnotch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP)+2 种基金Changjiang scholars program of the Ministry of Education(No.Q2018270)Excellent doctoral dissertation of Yangzhou universityUndergraduate scientific research innovation projects in Jiangsu province(No.201911117036Z)。
文摘Metal-organic frameworks(MOFs)with porous crystal structures have attracted extensive attention in application of energy storage and conversion,owing to their regularity,porosity,large specific surface area,etc.In this work,Co-MOF-74 microflower has been successfully prepared via a controllable solvent regulation strategy.Through modulating the polarity of the solvent,crystals grow in certain preferred orientation and Co-MOF-74 with various morphologies were obtained.Thereinto,the energy storage performance of Co-MOF-74 microflower was measured in both three-electrode system and asymmetric supercapacitor device(specific capacitance of 164.2 F/g at 0.5 A/g in the three-electrode system and 62.5 F/g at 1 A/g in the asymmetric supercapacitor device).This can be attributed to the preferred crystal orientation resulting in a regular and uniform microflower,which is of great significance to electronic interfacial exchange and ion transfer during electrochemical reactions.
基金supported by the National Key Research and Development Program of China (No. 2016YFA0203102)the National Natural Science Foundation of China (Nos. 21522706, 21677167 and 21577127)the Thousand Young Talents Program of China
文摘To obtain a cost-effective adsorbent for the removal of arsenic in water,a novel nanostructured Fe–Co based metal organic framework(MOF-74)adsorbent was successfully prepared via a simple solvothermal method.The adsorption experiments showed that the optimal molar ratio of Fe/Co in the adsorbent was 2:1.The Fe_2Co_1MOF-74 was characterized by various techniques and the results showed that the nanoparticle diameter ranged from60 to 80 nm and the specific surface area was 147.82 m^2/g.The isotherm and kinetic parameters of arsenic removal on Fe_2Co_1MOF-74 were well-fitted by the Langmuir and pseudo-second-order models.The maximum adsorption capacities toward As(III)and As(V)were 266.52 and 292.29 mg/g,respectively.The presence of sulfate,carbonate and humic acid had no obvious effect on arsenic adsorption.However,coexisting phosphate significantly hindered the removal of arsenic,especially at high concentrations(10 mmol/L).Electrostatic interaction and hydroxyl and metal–oxygen groups played important roles in the adsorption of arsenic.Furthermore,the prepared adsorbent had stable adsorption ability after regeneration and when used in a real-water matrix.The excellent adsorption performance of Fe_2Co_1MOF-74 material makes it a potentially promising adsorbent for the removal of arsenic.
