Nanosized Fe^3＋ and Eu^3＋ codoped CeO2 solid solutions were synthesized via hydrothermal method. The crystalline structure of Ce1-x（Fe0.5Eu0.5）xO2-δx=0.00–0.30） solid solutions was carried out by the X-ray diff...Nanosized Fe^3＋ and Eu^3＋ codoped CeO2 solid solutions were synthesized via hydrothermal method. The crystalline structure of Ce1-x（Fe0.5Eu0.5）xO2-δx=0.00–0.30） solid solutions was carried out by the X-ray diffraction technique, and the spectrum features were identified by UV-Vis and Raman spectroscopy, respectively. It was observed that the cell parameters were first increased then decreased by increasing the doped ions content. The phase separation was detected when the dopant concentration reached to x=0.30. UV-Vis spectrum showed that the width of the band gap gradually reduced by increasing the doped content, and the solid solubility was determined to be x=0.20. The Raman technique displayed that the peak position of F2g mode gradually shifted to lower frequencies from 465 cm^–1 for x=0.00 to 440 cm^–1 for x=0.20. The catalytic effects of Ce1-x（Fe0.5Eu0.5）xO2-δsolid solutions on the electrochemistry properties of Mg2Ni/Ni were measured by mixing them together via ball milling technique. The electrochemical properties of the Mg_2Ni/Ni-Ce1-x（Fe0.5Eu0.5）xO2-δcomposites showed that the maximum discharge capability Cmax and the cycle stability were improved obviously. Meanwhile, the EIS characteristic also indicated that the doped solid solutions could enhance the rate of charge transfer on the surface of alloy. The catalytic effect of the solid solutions was speculated to rely on both the concentration of oxygen vacancies and the cell volumes of the solid solutions.展开更多
Lithium-sulfur(Li-S)batteries have become prospective candidates for next-generation energy storage owing to the high energy density and low cost.However,the sluggish kinetics of the electrochemical reaction and shutt...Lithium-sulfur(Li-S)batteries have become prospective candidates for next-generation energy storage owing to the high energy density and low cost.However,the sluggish kinetics of the electrochemical reaction and shuttle effect result in a rapid capacity decay.Herein,a titanium nitride nanocrystal/Ndoped graphene(TiN@NG)composite is developed to host elemental sulfur.The TiN nanoparticles decorated on graphene sheets attract Li polysulfides(LiPSx)and catalyze the electrochemical reduction and oxidation of LiPSx in the discharge and charge processes,respectively.These two effects effectively restrain the dissolution of the LiPSx and accelerate the electrochemical reactions,thereby,alleviating the shuttle effect.As a result,the cathode composed of TiN@NG/S delivers a remarkable reversible capacity(1390 mA h g^(-1) at 0.1 C)and excellent cycling performance(730 mA h g^(-1) after 300 cycles).We believe that this work can bring some inspiration for designing high-performance Li-S batteries.展开更多
Butyl hexanoate(BuHE)is an important long-chain ester that is widely used in the food,beverage and cosmetic industries.In this work,reactive extraction concept was proposed to intensify the BuHE formation in a biphasi...Butyl hexanoate(BuHE)is an important long-chain ester that is widely used in the food,beverage and cosmetic industries.In this work,reactive extraction concept was proposed to intensify the BuHE formation in a biphasic system,in which deep eutectic solvent(DES)comprising 2-methylimidazole(2-MIm)and p-toluenesulfonic acid(PTSA)was used as dual solvent-catalyst.First,the effect of 2-MIm to PTSA molar ratio on esterification was investigated to determine the optimum DES of[2-MIm:2PTSA],which was characterized by FT-IR and TGA.Then,the liquid–liquid equilibrium(LLE)and esterification experiments were carried out to confirm the extraction and catalytic effect of[2-MIm:2PTSA],respectively.Afterwards,the pseudo-homogeneous kinetic model was employed to describe the esterification kinetics.Finally,the intensification mechanism of reactive extraction for BuHE formation was proposed according to the experiments and interaction effect analysis.展开更多
基金Project supported by the National Natural Science Foundation of China(51501059)Talent Incubation Funding of School of Materials and Metallurgy and Inner Mongolia University of Science and Technology(2014CY012)
文摘Nanosized Fe^3＋ and Eu^3＋ codoped CeO2 solid solutions were synthesized via hydrothermal method. The crystalline structure of Ce1-x（Fe0.5Eu0.5）xO2-δx=0.00–0.30） solid solutions was carried out by the X-ray diffraction technique, and the spectrum features were identified by UV-Vis and Raman spectroscopy, respectively. It was observed that the cell parameters were first increased then decreased by increasing the doped ions content. The phase separation was detected when the dopant concentration reached to x=0.30. UV-Vis spectrum showed that the width of the band gap gradually reduced by increasing the doped content, and the solid solubility was determined to be x=0.20. The Raman technique displayed that the peak position of F2g mode gradually shifted to lower frequencies from 465 cm^–1 for x=0.00 to 440 cm^–1 for x=0.20. The catalytic effects of Ce1-x（Fe0.5Eu0.5）xO2-δsolid solutions on the electrochemistry properties of Mg2Ni/Ni were measured by mixing them together via ball milling technique. The electrochemical properties of the Mg_2Ni/Ni-Ce1-x（Fe0.5Eu0.5）xO2-δcomposites showed that the maximum discharge capability Cmax and the cycle stability were improved obviously. Meanwhile, the EIS characteristic also indicated that the doped solid solutions could enhance the rate of charge transfer on the surface of alloy. The catalytic effect of the solid solutions was speculated to rely on both the concentration of oxygen vacancies and the cell volumes of the solid solutions.
基金funding support from the National Natural Science Foundation of China(51761145046,21975243,and 51672262)support from the 100 Talents Program of the Chinese Academy of Sciences+1 种基金National Program for Support of Top-notch Young ProfessionaliChEM。
文摘Lithium-sulfur(Li-S)batteries have become prospective candidates for next-generation energy storage owing to the high energy density and low cost.However,the sluggish kinetics of the electrochemical reaction and shuttle effect result in a rapid capacity decay.Herein,a titanium nitride nanocrystal/Ndoped graphene(TiN@NG)composite is developed to host elemental sulfur.The TiN nanoparticles decorated on graphene sheets attract Li polysulfides(LiPSx)and catalyze the electrochemical reduction and oxidation of LiPSx in the discharge and charge processes,respectively.These two effects effectively restrain the dissolution of the LiPSx and accelerate the electrochemical reactions,thereby,alleviating the shuttle effect.As a result,the cathode composed of TiN@NG/S delivers a remarkable reversible capacity(1390 mA h g^(-1) at 0.1 C)and excellent cycling performance(730 mA h g^(-1) after 300 cycles).We believe that this work can bring some inspiration for designing high-performance Li-S batteries.
基金support from National Natural Science Foundation of China(21776074 and 21576081)is greatly acknowledged.
文摘Butyl hexanoate(BuHE)is an important long-chain ester that is widely used in the food,beverage and cosmetic industries.In this work,reactive extraction concept was proposed to intensify the BuHE formation in a biphasic system,in which deep eutectic solvent(DES)comprising 2-methylimidazole(2-MIm)and p-toluenesulfonic acid(PTSA)was used as dual solvent-catalyst.First,the effect of 2-MIm to PTSA molar ratio on esterification was investigated to determine the optimum DES of[2-MIm:2PTSA],which was characterized by FT-IR and TGA.Then,the liquid–liquid equilibrium(LLE)and esterification experiments were carried out to confirm the extraction and catalytic effect of[2-MIm:2PTSA],respectively.Afterwards,the pseudo-homogeneous kinetic model was employed to describe the esterification kinetics.Finally,the intensification mechanism of reactive extraction for BuHE formation was proposed according to the experiments and interaction effect analysis.
