A novel high gravity multi-concentric cylinder electrodes-rotating bed(MCCE-RB) was developed for the electrocatalytic degradation of phenol wastewater in order to enhance the mass transfer with the self-made RuO_2-Ir...A novel high gravity multi-concentric cylinder electrodes-rotating bed(MCCE-RB) was developed for the electrocatalytic degradation of phenol wastewater in order to enhance the mass transfer with the self-made RuO_2-IrO_2-SnO_2/Ti anodes. The influences of electric current density, inlet liquid circulation flowrate, high gravity factor, sodium chloride concentration,and initial pH value on phenol degradation efficiency were investigated, with the optimal operating conditions determined. The results showed that under the optimal operating conditions covering a current density of 35 mA/cm^2, an inlet liquid circulation flowrate of 48 L/h, a high gravity factor of 20, a sodium chloride concentration of 8.5 g/L, an initial pH value of 6.5, a reaction time of 100 min, and an initial phenol concentration of 500 mg/L, the efficiency for removal of phenol reached 99.7%, which was improved by 10.4% as compared to that achieved in the normal gravity field. The tendency regarding the change in efficiency for removal of phenol, total organic carbon(TOC), and chemical oxygen demand(COD)over time was studied. The intermediates and degradation pathway of phenol were deduced by high performance liquid chromatography(HPLC).展开更多
As a promising alternative anode material,silicon(Si)presents a larger capacity than the commercial anode to achieve large capacity lithium-ion batteries.However,the application of pure Si as anode is hampered by limi...As a promising alternative anode material,silicon(Si)presents a larger capacity than the commercial anode to achieve large capacity lithium-ion batteries.However,the application of pure Si as anode is hampered by limitations such as volume expansion,low conductivity and unstable solid electrolyte interphase.To break through these limitations,the core-shell Si@Li4Ti5O12nanocomposite,which was prepared via in-situ self-assembly reaction and decompressive boiling fast concentration method,was proposed in this work.This anode combines the advantages of nano-sized Si particle and pure Li4Ti5O12(LTO)coating layer,improving the performance of the lithium-ion batteries.The Si@Li4Ti5O12 anode displays a high initial discharge/charge specific capacity of 1756/1383 m Ahg^-1 at 500 mAg^-1(representing high initial coulombic efficiency of 78.8%),a large rate capability(specific capacity of 620 mAhg^-1 at4000 mAg^-1),an outstanding cycling stability(reversible specific capacity of 883 mAhg^-1 after 150 cycles)and a low volume expansion rate(only 3.3% after 150 cycles).Moreover,the synthesis process shows the merits of efficiency,simplicity,and economy,providing a reliable method to fabricate large capacity Si@Li4Ti5O12nanocomposite anode materials for practical lithium-ion batteries.展开更多
The ethanol electro-reforming process was studied over PtRu/C catalysts synthesized by the modified polyol method with different compositions.In particular,this work reports the influence of anodic Pt:Ru ratio(5:1,2:1...The ethanol electro-reforming process was studied over PtRu/C catalysts synthesized by the modified polyol method with different compositions.In particular,this work reports the influence of anodic Pt:Ru ratio(5:1,2:1 and 1:2)on the organic product distribution(acetaldehyde,acetic acid and ethyl acetate)and pure hydrogen generation at different current densities operation levels.Physicochemical characterization of the catalysts was made by X-ray diffraction(XRD),temperature-programmed reduction(TPR)and N_(2) adsorption-desorption measurements.XRD patterns showed that Ru is introduced into the Pt structure,forming an alloy between both metals.Also,the degree of alloy was higher by increasing the Ru amounts.From TPR profiles Pt was found to be properly reduced while Ru was both in metallic state and forming RuO2.The electrochemical behaviour of each catalyst towards ethanol electroreforming process was investigated through electrochemical techniques in a half cell and a single proton exchange membrane(PEM)cell systems.An intermediate Pt:Ru ratio was found to result in high current density and electrochemical surface area(ECSA)values along with lower amounts of adsorbed species.Also,Ru addition seems to diminish the degree of degradation of the catalyst.Based on characterization and in agreement with essays carried out in a PEM cell at mild conditions(80℃ and 1 atm),PtRu/C 2:1 anode provided the best electrocatalytic results in terms of current density(740 mA cm^(-2)),hydrogen production and selectivity toward acetic acid(up to 15%apart from acetaldehyde and ethyl acetate)while requiring the lowest energy consumption.展开更多
Although lithium(Li)and sodium(Na)metals can be selected as the promising anode materials for next‐generation rechargeable batteries of high energy density,their practical applications are greatly restricted by the u...Although lithium(Li)and sodium(Na)metals can be selected as the promising anode materials for next‐generation rechargeable batteries of high energy density,their practical applications are greatly restricted by the uncontrollable dendrite growth.Herein,a platinum(Pt)–copper(Cu)alloycoated Cu foam(Pt–Cu foam)is prepared and then used as the substrate for Li and Na metal anodes.Owing to the ultrarough morphology with a threedimensional porous structure and the quite large surface area as well as lithiophilicity and sodiophilicity,both Li and Na dendrite growths are significantly suppressed on the substrate.Moreover,during Li plating,the lithiated Pt atoms can dissolve into Li phase,leaving a lot of microsized holes on the substrate.During Na plating,although the sodiated Pt atoms cannot dissolve into Na phase,the sodiation of Pt atoms elevates many microsized blocks above the current collector.Either the holes or the voids on the surface of Pt–Cu foam what can be extra place for deposited alkali metal,what effectively relaxes the internal stress caused by the volume exchange during Li and Na plating/stripping.Therefore,the symmetric batteries of Li@Pt–Cu foam and Na@Pt–Cu foam have both achieved long‐term cycling stability even at ultrahigh areal capacity at 20 mAh cm−2.展开更多
Metatitanic acid was synthesized from industrial titanyl sulfate solution via controlling pH during hydrolyzing process. Inductively coupled plasma(ICP)analysis confirmed that a little Fe,Mg and Ca were deposited into...Metatitanic acid was synthesized from industrial titanyl sulfate solution via controlling pH during hydrolyzing process. Inductively coupled plasma(ICP)analysis confirmed that a little Fe,Mg and Ca were deposited into precursor TiO2·H2O.Spinel Li4Ti5O12 was prepared by sintering amorphous mixture at 800℃for 16 h.The amorphous mixture was activated by ball-milling at room temperature,using the as-prepared TiO2·H2O and Li2CO3 as raw materials.The sample was characterized by X-ray diffractometry,scanning electron microscopy and electrochemical charge and discharge test.The results show that spinel Li4Ti5O12 is obtained,but it contains a few rutile TiO2 impurities.The sample has fine particles with size of around 50 nm and homogenous size distribution.At room temperature,the initial reversible specific capacity of the sample is 136.9,128.0,119.2 and 96.3 mA·h/g at 0.1C, 1C,2C and 5C,respectively,and the sample shows excellent cycling performance.展开更多
The passivation behavior of insoluble anode from 8 kinds of Ti-base alloys in the 40% H_2SO_4(aq)and1 mol/L MnSO_4 -0.75 mol/L H_2SO_4 was studied respectively by analyzing potential-controlling stationarypolarizatio...The passivation behavior of insoluble anode from 8 kinds of Ti-base alloys in the 40% H_2SO_4(aq)and1 mol/L MnSO_4 -0.75 mol/L H_2SO_4 was studied respectively by analyzing potential-controlling stationarypolarization curve. Results indicate that the passivation curves of Ti-base alloy insoluble anode are analogousto that of pare titanium anodc in spite of the critical passivation current density i_b for the former is somewhathigher and passivation retaining current density i_p increases significantly, the passivation region diminishes.the passivation becomes not so clear. Ou the basis of electrochemical and X-ray diffraction data the passivationmechanism of pure titanium anode in EMD industry is discussed and authors suggest that the Ti- base alloyanode is better than the pure titanium anode.展开更多
基金financially supported by the Nature Science Foundation of China (Grant No.U1610106)the Nature Science Foundation of China (Grant No.21703208)
文摘A novel high gravity multi-concentric cylinder electrodes-rotating bed(MCCE-RB) was developed for the electrocatalytic degradation of phenol wastewater in order to enhance the mass transfer with the self-made RuO_2-IrO_2-SnO_2/Ti anodes. The influences of electric current density, inlet liquid circulation flowrate, high gravity factor, sodium chloride concentration,and initial pH value on phenol degradation efficiency were investigated, with the optimal operating conditions determined. The results showed that under the optimal operating conditions covering a current density of 35 mA/cm^2, an inlet liquid circulation flowrate of 48 L/h, a high gravity factor of 20, a sodium chloride concentration of 8.5 g/L, an initial pH value of 6.5, a reaction time of 100 min, and an initial phenol concentration of 500 mg/L, the efficiency for removal of phenol reached 99.7%, which was improved by 10.4% as compared to that achieved in the normal gravity field. The tendency regarding the change in efficiency for removal of phenol, total organic carbon(TOC), and chemical oxygen demand(COD)over time was studied. The intermediates and degradation pathway of phenol were deduced by high performance liquid chromatography(HPLC).
基金the financial support from the National Natural Science Foundation of China (51876052, 51676128)
文摘As a promising alternative anode material,silicon(Si)presents a larger capacity than the commercial anode to achieve large capacity lithium-ion batteries.However,the application of pure Si as anode is hampered by limitations such as volume expansion,low conductivity and unstable solid electrolyte interphase.To break through these limitations,the core-shell Si@Li4Ti5O12nanocomposite,which was prepared via in-situ self-assembly reaction and decompressive boiling fast concentration method,was proposed in this work.This anode combines the advantages of nano-sized Si particle and pure Li4Ti5O12(LTO)coating layer,improving the performance of the lithium-ion batteries.The Si@Li4Ti5O12 anode displays a high initial discharge/charge specific capacity of 1756/1383 m Ahg^-1 at 500 mAg^-1(representing high initial coulombic efficiency of 78.8%),a large rate capability(specific capacity of 620 mAhg^-1 at4000 mAg^-1),an outstanding cycling stability(reversible specific capacity of 883 mAhg^-1 after 150 cycles)and a low volume expansion rate(only 3.3% after 150 cycles).Moreover,the synthesis process shows the merits of efficiency,simplicity,and economy,providing a reliable method to fabricate large capacity Si@Li4Ti5O12nanocomposite anode materials for practical lithium-ion batteries.
基金the Spanish Ministry of Economy and Competitiveness(projects CTQ2016-75491-R)for the financial support。
文摘The ethanol electro-reforming process was studied over PtRu/C catalysts synthesized by the modified polyol method with different compositions.In particular,this work reports the influence of anodic Pt:Ru ratio(5:1,2:1 and 1:2)on the organic product distribution(acetaldehyde,acetic acid and ethyl acetate)and pure hydrogen generation at different current densities operation levels.Physicochemical characterization of the catalysts was made by X-ray diffraction(XRD),temperature-programmed reduction(TPR)and N_(2) adsorption-desorption measurements.XRD patterns showed that Ru is introduced into the Pt structure,forming an alloy between both metals.Also,the degree of alloy was higher by increasing the Ru amounts.From TPR profiles Pt was found to be properly reduced while Ru was both in metallic state and forming RuO2.The electrochemical behaviour of each catalyst towards ethanol electroreforming process was investigated through electrochemical techniques in a half cell and a single proton exchange membrane(PEM)cell systems.An intermediate Pt:Ru ratio was found to result in high current density and electrochemical surface area(ECSA)values along with lower amounts of adsorbed species.Also,Ru addition seems to diminish the degree of degradation of the catalyst.Based on characterization and in agreement with essays carried out in a PEM cell at mild conditions(80℃ and 1 atm),PtRu/C 2:1 anode provided the best electrocatalytic results in terms of current density(740 mA cm^(-2)),hydrogen production and selectivity toward acetic acid(up to 15%apart from acetaldehyde and ethyl acetate)while requiring the lowest energy consumption.
基金The authors acknowledge the support of the National Nature Science Foundation of China (21908124)Zhaoqing Xijiang Talent Program.
文摘Although lithium(Li)and sodium(Na)metals can be selected as the promising anode materials for next‐generation rechargeable batteries of high energy density,their practical applications are greatly restricted by the uncontrollable dendrite growth.Herein,a platinum(Pt)–copper(Cu)alloycoated Cu foam(Pt–Cu foam)is prepared and then used as the substrate for Li and Na metal anodes.Owing to the ultrarough morphology with a threedimensional porous structure and the quite large surface area as well as lithiophilicity and sodiophilicity,both Li and Na dendrite growths are significantly suppressed on the substrate.Moreover,during Li plating,the lithiated Pt atoms can dissolve into Li phase,leaving a lot of microsized holes on the substrate.During Na plating,although the sodiated Pt atoms cannot dissolve into Na phase,the sodiation of Pt atoms elevates many microsized blocks above the current collector.Either the holes or the voids on the surface of Pt–Cu foam what can be extra place for deposited alkali metal,what effectively relaxes the internal stress caused by the volume exchange during Li and Na plating/stripping.Therefore,the symmetric batteries of Li@Pt–Cu foam and Na@Pt–Cu foam have both achieved long‐term cycling stability even at ultrahigh areal capacity at 20 mAh cm−2.
基金Project(2007CB613607)supported by the National Basic Research Program of China
文摘Metatitanic acid was synthesized from industrial titanyl sulfate solution via controlling pH during hydrolyzing process. Inductively coupled plasma(ICP)analysis confirmed that a little Fe,Mg and Ca were deposited into precursor TiO2·H2O.Spinel Li4Ti5O12 was prepared by sintering amorphous mixture at 800℃for 16 h.The amorphous mixture was activated by ball-milling at room temperature,using the as-prepared TiO2·H2O and Li2CO3 as raw materials.The sample was characterized by X-ray diffractometry,scanning electron microscopy and electrochemical charge and discharge test.The results show that spinel Li4Ti5O12 is obtained,but it contains a few rutile TiO2 impurities.The sample has fine particles with size of around 50 nm and homogenous size distribution.At room temperature,the initial reversible specific capacity of the sample is 136.9,128.0,119.2 and 96.3 mA·h/g at 0.1C, 1C,2C and 5C,respectively,and the sample shows excellent cycling performance.
基金Project supported by the Key Special Projects of the Ministry of Science and Technology(China:2021YFE0104300 and Uzbekistan:MUK-2021-45)Project(202302AH360001)supported by the Science Research Project of Yunnan Province,ChinaProject(2021P4FZG09A)supported by the Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization,China。
文摘The passivation behavior of insoluble anode from 8 kinds of Ti-base alloys in the 40% H_2SO_4(aq)and1 mol/L MnSO_4 -0.75 mol/L H_2SO_4 was studied respectively by analyzing potential-controlling stationarypolarization curve. Results indicate that the passivation curves of Ti-base alloy insoluble anode are analogousto that of pare titanium anodc in spite of the critical passivation current density i_b for the former is somewhathigher and passivation retaining current density i_p increases significantly, the passivation region diminishes.the passivation becomes not so clear. Ou the basis of electrochemical and X-ray diffraction data the passivationmechanism of pure titanium anode in EMD industry is discussed and authors suggest that the Ti- base alloyanode is better than the pure titanium anode.
