Porous carbons were obtained from rice husk using two different chemical activation methods and they were investigated as supercapacitors.Their properties were studied using X-ray photoelectron spectroscopy,thermal an...Porous carbons were obtained from rice husk using two different chemical activation methods and they were investigated as supercapacitors.Their properties were studied using X-ray photoelectron spectroscopy,thermal analysis,potentiometric titration,and nitrogen adsorption isotherm.The specific capacitance measured in both H_(2) SO_(4) and KOH electrolytes in two-electrode cell was up to-150 F/g.The activation method used affected the resulting carbons’features.As expected,the dependence of the capacitance on porosity was found.The ash content reached 36 wt.%and that inorganic mater blocked some pores and limited their accessibility to electrolyte ions and increased the charge transfer resistance.Nevertheless,the main ash constituents such as CaCO_(3),MgCO_(3),Ca_(3)(PO_(4))2(or P_(2)O_(5)),and Fe-and Zn-containing species did not affect the specific capacitance to a large extent.Especially SiO2,even in a relatively large amount(~20 wt.%)T did not play a detrimental role in the capacitance behavior.The results showed that in spite of a high ash content,carbon can exhibit a good capacitive performance provided that it has a favorable porosity and is rich in sp_(2) configurations.展开更多
The capacitance performances of poly（3,4-ethylenedioxythiophene）-poly（styrenesulfonate）（PEDOT-PSS） supramolecular hydrogels have been investigated systematically. The materials show a specific capacitance of 67 ...The capacitance performances of poly（3,4-ethylenedioxythiophene）-poly（styrenesulfonate）（PEDOT-PSS） supramolecular hydrogels have been investigated systematically. The materials show a specific capacitance of 67 F/g and display excellent rate capability at the scan rate as high as 5000 m V/s in the cyclic voltammogram measurements, accompanied by good cycle stability. On the basis of the measurements of the microscale morphologies, specific areas and electrical conductivities, the mechanisms for the improvement of the electrochemical properties are discussed and ascribed to the novel porous microstructures of the hydrogels and the synergetic effect of the rigid PEDOT and soft PSS components. Furthermore, polyaniline（PAn） is compounded with the PEDOT-PSS hydrogels through an interfacial polymerization process, endowing the hydrogel materials with a higher specific capacitance of 160 F/g at the scan rate of 5000 m V/s. The significance of this work lies in the demonstration of a novel method to solve the problems of conducting polymers in electrochemical applications.展开更多
A bi-As-capped and tetra-V-substituted arsenomolybdate(Hbib)_(2)(biyb)_(3)[As^(Ⅲ)_(2)As^(Ⅴ)Mo^(Ⅵ)8V^(Ⅴ)_(4)O_(40)]_(2)·H_(2)O(1)(bib=1.4-Bis(imidazoly)butane;biyb=1,4-bis(imidazol-1-ylmethyl)benzene)has been ...A bi-As-capped and tetra-V-substituted arsenomolybdate(Hbib)_(2)(biyb)_(3)[As^(Ⅲ)_(2)As^(Ⅴ)Mo^(Ⅵ)8V^(Ⅴ)_(4)O_(40)]_(2)·H_(2)O(1)(bib=1.4-Bis(imidazoly)butane;biyb=1,4-bis(imidazol-1-ylmethyl)benzene)has been constructed through hydrothermal methods and characterized by conventional method.Compound 1 is a tetra-V substituted{AsMo^(Ⅵ)_(8)V^(Ⅴ)_(4)O_(4)}polyanions capped by two AsⅢcations at two symmetrical ditch in{AsO_(4)}rectangular pyramid geometry.It exhibits higher specific capacitance,capacitance retention,and electrocatalytic activities for oxidizing ascorbic acid and reducing peroxide hydrogen.展开更多
文摘Porous carbons were obtained from rice husk using two different chemical activation methods and they were investigated as supercapacitors.Their properties were studied using X-ray photoelectron spectroscopy,thermal analysis,potentiometric titration,and nitrogen adsorption isotherm.The specific capacitance measured in both H_(2) SO_(4) and KOH electrolytes in two-electrode cell was up to-150 F/g.The activation method used affected the resulting carbons’features.As expected,the dependence of the capacitance on porosity was found.The ash content reached 36 wt.%and that inorganic mater blocked some pores and limited their accessibility to electrolyte ions and increased the charge transfer resistance.Nevertheless,the main ash constituents such as CaCO_(3),MgCO_(3),Ca_(3)(PO_(4))2(or P_(2)O_(5)),and Fe-and Zn-containing species did not affect the specific capacitance to a large extent.Especially SiO2,even in a relatively large amount(~20 wt.%)T did not play a detrimental role in the capacitance behavior.The results showed that in spite of a high ash content,carbon can exhibit a good capacitive performance provided that it has a favorable porosity and is rich in sp_(2) configurations.
基金financially supported by the National Natural Science Foundation of China(Nos.21174059 and 21374046)China Postdoctoral Science Foundation(No.2013M530249)+1 种基金Program for Changjiang Scholars and Innovative Research Teams in Universities,Open Project of State Key Laboratory of Superamolecular Structure and Materials(No.SKLSSM201416)the Testing Foundation of Nanjing University
文摘The capacitance performances of poly（3,4-ethylenedioxythiophene）-poly（styrenesulfonate）（PEDOT-PSS） supramolecular hydrogels have been investigated systematically. The materials show a specific capacitance of 67 F/g and display excellent rate capability at the scan rate as high as 5000 m V/s in the cyclic voltammogram measurements, accompanied by good cycle stability. On the basis of the measurements of the microscale morphologies, specific areas and electrical conductivities, the mechanisms for the improvement of the electrochemical properties are discussed and ascribed to the novel porous microstructures of the hydrogels and the synergetic effect of the rigid PEDOT and soft PSS components. Furthermore, polyaniline（PAn） is compounded with the PEDOT-PSS hydrogels through an interfacial polymerization process, endowing the hydrogel materials with a higher specific capacitance of 160 F/g at the scan rate of 5000 m V/s. The significance of this work lies in the demonstration of a novel method to solve the problems of conducting polymers in electrochemical applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.22171061 and 21771046)the 2020 Central Government’s plan to support the Talent Training Project of the Reform and Development Fund of Local Universities(1401120002)+1 种基金the Natural Science Foundation of Heilongjiang Province of China(ZD2021B002 and TD2020B001)the Excellent Scientific Research Team Project of Harbin Normal University(XKYT202001)。
文摘A bi-As-capped and tetra-V-substituted arsenomolybdate(Hbib)_(2)(biyb)_(3)[As^(Ⅲ)_(2)As^(Ⅴ)Mo^(Ⅵ)8V^(Ⅴ)_(4)O_(40)]_(2)·H_(2)O(1)(bib=1.4-Bis(imidazoly)butane;biyb=1,4-bis(imidazol-1-ylmethyl)benzene)has been constructed through hydrothermal methods and characterized by conventional method.Compound 1 is a tetra-V substituted{AsMo^(Ⅵ)_(8)V^(Ⅴ)_(4)O_(4)}polyanions capped by two AsⅢcations at two symmetrical ditch in{AsO_(4)}rectangular pyramid geometry.It exhibits higher specific capacitance,capacitance retention,and electrocatalytic activities for oxidizing ascorbic acid and reducing peroxide hydrogen.
