In the presence of 1-（3-dimethylaminopropyl）-3-ethylcarbodiimide hydrochloride （EDC） and N-hydroxysuccinimide （NHS）, carboxylic group-functionalized single-walled carbon nanotubes （SWNTs） were assembled vertic...In the presence of 1-（3-dimethylaminopropyl）-3-ethylcarbodiimide hydrochloride （EDC） and N-hydroxysuccinimide （NHS）, carboxylic group-functionalized single-walled carbon nanotubes （SWNTs） were assembled vertically on the glassy carbon electrode using ethylenediamine as linking agent to fabricate an aligned electrode （SWNTE）. The morphological characteristic was studied with atomic force microscope （AFM） and its electrochemical property was investigated using K3[Fe（CN）6] as probe. ssDNA had a sensitive voltammetric response at the SWNTE and the oxidative peak potentials of guanine base and adenine base were 0.608 Vand 0.896 V, respectively. Under the optimal conditions, the DPV peak current of guanine base vs. the concentration of ssDNA was linear in the range of 5.4 μg/L-10.8 mg/L with a detection limit of 1 μg/L （S/N = 3）.展开更多
Conventional electrode preparation techniques of supercapacitors such as tape casting or vacuum filtration often lead to the restacking or agglomeration of twodimensional(2 D)materials.As a result,tortuous paths are c...Conventional electrode preparation techniques of supercapacitors such as tape casting or vacuum filtration often lead to the restacking or agglomeration of twodimensional(2 D)materials.As a result,tortuous paths are created for the electrolyte ions and their adsorption onto the surfaces of the active materials can be prevented.Consequently,maintaining high rate performance while increasing the thickness of electrodes has been a challenge.Herein,a facile freeze-assisted tape-casting(Fa TC)method is reported for the scalable fabrication of flexible MXene(Ti3C2Tx)supercapacitor electrode films of up to 700μm thickness,exhibiting homogeneous ice-template microstructure composed of vertically aligned MXene walls within lamellar pores.The efficient ion transport created by the internal morphology allows for fast electrochemical charge–discharge cycles and near thickness-independent performance at up to 3000 m V s-1 for films of up to 300μm in thickness.By increasing the scan rate from 20 to 10,000 m V s-1,Ti3C2Tx films of 150μm in thickness sustain 50%of its specific capacitance(222.9 F g-1).When the film thickness is doubled to 300μm,its capacitance is still retained by 60%(at 213.3 F g-1)when the scan rate is increased from 20 to3000 m V s-1,with a capacitance retention above 97.7%for over 14,000 cycles at10 A g-1.They also showed a remarkably high gravimetric and areal power density of 150 k W kg-1 at 1000 A g-1 and 667 m W cm-2 at 4444 m A cm-2,respectively.Fa TC has the potential to provide industry with a viable way to fabricate electrodes formed from 2 D materials on a large scale,while providing promising performance for use in a wide range of applications,such as flexible electronics and wearable energy storage devices.展开更多
基金supports from the National Science Foundation of China(No.20635020,No.20375020)Doctoral Foundation of the Ministry of Education of China(No.20060426001).
文摘In the presence of 1-（3-dimethylaminopropyl）-3-ethylcarbodiimide hydrochloride （EDC） and N-hydroxysuccinimide （NHS）, carboxylic group-functionalized single-walled carbon nanotubes （SWNTs） were assembled vertically on the glassy carbon electrode using ethylenediamine as linking agent to fabricate an aligned electrode （SWNTE）. The morphological characteristic was studied with atomic force microscope （AFM） and its electrochemical property was investigated using K3[Fe（CN）6] as probe. ssDNA had a sensitive voltammetric response at the SWNTE and the oxidative peak potentials of guanine base and adenine base were 0.608 Vand 0.896 V, respectively. Under the optimal conditions, the DPV peak current of guanine base vs. the concentration of ssDNA was linear in the range of 5.4 μg/L-10.8 mg/L with a detection limit of 1 μg/L （S/N = 3）.
基金supported by the Henry Royce Institute for Advanced Materials,funded through EPSRC grants EP/R00661X/1,EP/S019367/1,EP/P025021/1,and EP/P025498/1the University of Manchester for the President’s Doctoral Scholar AwardEPSRC for funding through the grants EP/R023034/1 and EP/N032888/1
文摘Conventional electrode preparation techniques of supercapacitors such as tape casting or vacuum filtration often lead to the restacking or agglomeration of twodimensional(2 D)materials.As a result,tortuous paths are created for the electrolyte ions and their adsorption onto the surfaces of the active materials can be prevented.Consequently,maintaining high rate performance while increasing the thickness of electrodes has been a challenge.Herein,a facile freeze-assisted tape-casting(Fa TC)method is reported for the scalable fabrication of flexible MXene(Ti3C2Tx)supercapacitor electrode films of up to 700μm thickness,exhibiting homogeneous ice-template microstructure composed of vertically aligned MXene walls within lamellar pores.The efficient ion transport created by the internal morphology allows for fast electrochemical charge–discharge cycles and near thickness-independent performance at up to 3000 m V s-1 for films of up to 300μm in thickness.By increasing the scan rate from 20 to 10,000 m V s-1,Ti3C2Tx films of 150μm in thickness sustain 50%of its specific capacitance(222.9 F g-1).When the film thickness is doubled to 300μm,its capacitance is still retained by 60%(at 213.3 F g-1)when the scan rate is increased from 20 to3000 m V s-1,with a capacitance retention above 97.7%for over 14,000 cycles at10 A g-1.They also showed a remarkably high gravimetric and areal power density of 150 k W kg-1 at 1000 A g-1 and 667 m W cm-2 at 4444 m A cm-2,respectively.Fa TC has the potential to provide industry with a viable way to fabricate electrodes formed from 2 D materials on a large scale,while providing promising performance for use in a wide range of applications,such as flexible electronics and wearable energy storage devices.
