A precursor of cobaltous dihydroxycarbonate was firstly prepared by precipitation reaction of cobalt sulfate solution and ammonium carbonate solution,and then a hydrothermal process for the precursor was conducted to ...A precursor of cobaltous dihydroxycarbonate was firstly prepared by precipitation reaction of cobalt sulfate solution and ammonium carbonate solution,and then a hydrothermal process for the precursor was conducted to obtain the spherical cobalt carbonate with low sulfur content.The experimental results show that the feeding method,final p H value of the precipitation reaction slurry and the concentration of the cobalt sulfate solution have obvious effects on the sulfur content,morphology and particle size distribution of the precursor.The sulfur content of the precursor is 0.0115 wt.%under the optimized conditions.The hydrothermal treatment with temperatures of 125-150℃can transform the precursor of cobaltous dihydroxycarbonate into spherical cobalt carbonate and decrease the sulfur content to 0.0030 wt.%in the obtained product.展开更多
SP-C was applied for the removal of Cu^2＋ from simulated cobalt sulfate electrolyte containing Co2＋ 50 g/L and Cu2＋ 0.5-2.0 g/L. Experimental conditions included pH of 2-4, temperature of 20-60℃ and contact time o...SP-C was applied for the removal of Cu^2＋ from simulated cobalt sulfate electrolyte containing Co2＋ 50 g/L and Cu2＋ 0.5-2.0 g/L. Experimental conditions included pH of 2-4, temperature of 20-60℃ and contact time of 10-40 min. The investigation demonstrated that SP-C had recommendable efficiency in adsorbing Cu2＋ from the electrolyte with 25- to 100-fold of Co2＋ The optimal adsorption conditions of SP-C were pH of 4, contact time of 30 min and ambient temperature. The study also showed that the loaded resin could be effectively eluted with 2.0 mol/L H2SO4 solution at a contact time of 40 min; the peak concentration of Cu2＋ in the eluate was about 35 g/L. The sorption characteristics of Cu2＋ by SP-C could be described by Langrnuir isotherm and the pseudo second-order kinetic equation. Infrared spectra showed that nitrogen atoms in the functional group coordinated with Cu2＋ to form coordination bands.展开更多
A mild and efficient method for diacetylation reaction was developed,by which diacetate could be achieved through the reaction of aldehyde with acetic anhydride,in the presence of cobalt sulfate,with an admirable yiel...A mild and efficient method for diacetylation reaction was developed,by which diacetate could be achieved through the reaction of aldehyde with acetic anhydride,in the presence of cobalt sulfate,with an admirable yield,at room temperature,without solvent.The catalyst could be recycled six times without a distinct loss of activity.展开更多
Generally,the metal sulfide itself has poor conductivity,and the volume expansion occurs when it is converted with sodium,which will destroy the integrity of the electrode structure,resulting in poor cycle performance...Generally,the metal sulfide itself has poor conductivity,and the volume expansion occurs when it is converted with sodium,which will destroy the integrity of the electrode structure,resulting in poor cycle performance and rate performance.To solve the problems of low initial coulombic efficiency(ICE)and volume expansion of metal compounds used as anodes in sodium-ion batteries(SIBs).Inspired by nature,the CoSO_(4)/hard carbon/graphene(CHG)fractal structure electrode was designed.Self-fractal structures with electron/ion transport channels and high strain tolerance proved to be an effective strategy to overcome these challenges.The fractal dimension(D)is measured by synchronous Small Angle X-ray scattering,and the D remains stable during charging and discharging.The fractal CHG also showed excellent electrochemical performance,especially 97.4%ICE.Theoretical calculation shows that self-fractal CHG can promote the formation of a thin solid electrolyte interface(SEI).Synchrotron radiation absorption spectrum proved the reaction mechanism of CHG.This study not only proves that cobalt sulfate is a feasible strategy for developing high-performance SIBs anodes but also provides an advanced method for measuring the fractal dimension of energy storage electrode materials.展开更多
基金Project(51874372)supported by the National Natural Science Foundation of China
文摘A precursor of cobaltous dihydroxycarbonate was firstly prepared by precipitation reaction of cobalt sulfate solution and ammonium carbonate solution,and then a hydrothermal process for the precursor was conducted to obtain the spherical cobalt carbonate with low sulfur content.The experimental results show that the feeding method,final p H value of the precipitation reaction slurry and the concentration of the cobalt sulfate solution have obvious effects on the sulfur content,morphology and particle size distribution of the precursor.The sulfur content of the precursor is 0.0115 wt.%under the optimized conditions.The hydrothermal treatment with temperatures of 125-150℃can transform the precursor of cobaltous dihydroxycarbonate into spherical cobalt carbonate and decrease the sulfur content to 0.0030 wt.%in the obtained product.
文摘SP-C was applied for the removal of Cu^2＋ from simulated cobalt sulfate electrolyte containing Co2＋ 50 g/L and Cu2＋ 0.5-2.0 g/L. Experimental conditions included pH of 2-4, temperature of 20-60℃ and contact time of 10-40 min. The investigation demonstrated that SP-C had recommendable efficiency in adsorbing Cu2＋ from the electrolyte with 25- to 100-fold of Co2＋ The optimal adsorption conditions of SP-C were pH of 4, contact time of 30 min and ambient temperature. The study also showed that the loaded resin could be effectively eluted with 2.0 mol/L H2SO4 solution at a contact time of 40 min; the peak concentration of Cu2＋ in the eluate was about 35 g/L. The sorption characteristics of Cu2＋ by SP-C could be described by Langrnuir isotherm and the pseudo second-order kinetic equation. Infrared spectra showed that nitrogen atoms in the functional group coordinated with Cu2＋ to form coordination bands.
文摘A mild and efficient method for diacetylation reaction was developed,by which diacetate could be achieved through the reaction of aldehyde with acetic anhydride,in the presence of cobalt sulfate,with an admirable yield,at room temperature,without solvent.The catalyst could be recycled six times without a distinct loss of activity.
基金supported by Beijing Synchrotron Radiation 1W2A Work Station and 4B9A Work Station in China and was financially supported by National Natural Science Foundation of China(No.52250710161).
文摘Generally,the metal sulfide itself has poor conductivity,and the volume expansion occurs when it is converted with sodium,which will destroy the integrity of the electrode structure,resulting in poor cycle performance and rate performance.To solve the problems of low initial coulombic efficiency(ICE)and volume expansion of metal compounds used as anodes in sodium-ion batteries(SIBs).Inspired by nature,the CoSO_(4)/hard carbon/graphene(CHG)fractal structure electrode was designed.Self-fractal structures with electron/ion transport channels and high strain tolerance proved to be an effective strategy to overcome these challenges.The fractal dimension(D)is measured by synchronous Small Angle X-ray scattering,and the D remains stable during charging and discharging.The fractal CHG also showed excellent electrochemical performance,especially 97.4%ICE.Theoretical calculation shows that self-fractal CHG can promote the formation of a thin solid electrolyte interface(SEI).Synchrotron radiation absorption spectrum proved the reaction mechanism of CHG.This study not only proves that cobalt sulfate is a feasible strategy for developing high-performance SIBs anodes but also provides an advanced method for measuring the fractal dimension of energy storage electrode materials.
