In this paper,we synthesized cathode catalysts(PANI-PPYR,Fe/PANI-PPYR,Co/PANI-PPYR and Fe-Co/PANI-PPYR)with high performance oxygen reduction by using a simple heat treatment process.These catalysts were fabricated by...In this paper,we synthesized cathode catalysts(PANI-PPYR,Fe/PANI-PPYR,Co/PANI-PPYR and Fe-Co/PANI-PPYR)with high performance oxygen reduction by using a simple heat treatment process.These catalysts were fabricated by directly calcining the Fe and/or Co doped polyaniline(PANI)-polypyrrole(PPYR)composites.Their electrocatalytic activity for ORR both in acidic and in alkaline media was investigated by voltammetric techniques.Among the prepared catalysts,Co/PANI-PPYR presents the most positive ORR onset potential of 0.62 V(vs.SCE)in 0.5 mol/L H2SO4 solution or?0.09 V(vs.SCE)in 1 mol/L NaOH solution.In addition,the Co/PANI-PPYR catalyst shows the largest limiting-diffusion current density for ORR,which is 4.3 mA/cm2@0.2 V(vs.SCE)in acidic and 2.3 mA/cm2@?0.3 V(vs.SCE)in alkaline media.In acidic media,a four-electron reaction of ORR on the Co/PANI-PPYR and Fe/PANI-PPYR catalysts is more dominant than a two-electron reaction.In alkaline media,however,a four-electron and a two-electron mechanisms are co-present for the ORR on all the prepared catalysts.Co/PANI-PPYR catalyst also presents good electrocatalytic activity stability for ORR both in acidic and in alkaline media.展开更多
Nitrogen-doped carbon nanotubes (N-CNTs)/polyaniline (PANI) composites are developed as an electrode material for biosensors. The morphology, composition, and optical properties of the resulting products were characte...Nitrogen-doped carbon nanotubes (N-CNTs)/polyaniline (PANI) composites are developed as an electrode material for biosensors. The morphology, composition, and optical properties of the resulting products were characterized by transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible absorption spectra (UV-vis). Furthermore, N-CNTs/PANI composite was immobilized on the surface of a glassy carbon electrode (GCE) and applied to construct a sensor. The obtained N-CNTs/PANI-modified GCE showed one pair of redox peaks and high catalytic activity for the oxidation of dopamine (DA) in a neutral environment. Differential pulse voltam-mograms results illustrate that the fabricated DA biosensor has high anti-interference ability towards ascorbic acid (AA). In addition, the fabricated biosensor showed superior performances with two wide linear ranges from 1 to 80 μM and from 1.5 to 3.5 mM and a low detection limit of 0.01 μM.展开更多
基金supported by the National Natural Science Foundation of China(21376070,20876038)the Scientific Research Fund of Hunan Provincial Education Department(11K023)Hunan Provincial Natural Science Foundation of China(14JJ2096)
文摘In this paper,we synthesized cathode catalysts(PANI-PPYR,Fe/PANI-PPYR,Co/PANI-PPYR and Fe-Co/PANI-PPYR)with high performance oxygen reduction by using a simple heat treatment process.These catalysts were fabricated by directly calcining the Fe and/or Co doped polyaniline(PANI)-polypyrrole(PPYR)composites.Their electrocatalytic activity for ORR both in acidic and in alkaline media was investigated by voltammetric techniques.Among the prepared catalysts,Co/PANI-PPYR presents the most positive ORR onset potential of 0.62 V(vs.SCE)in 0.5 mol/L H2SO4 solution or?0.09 V(vs.SCE)in 1 mol/L NaOH solution.In addition,the Co/PANI-PPYR catalyst shows the largest limiting-diffusion current density for ORR,which is 4.3 mA/cm2@0.2 V(vs.SCE)in acidic and 2.3 mA/cm2@?0.3 V(vs.SCE)in alkaline media.In acidic media,a four-electron reaction of ORR on the Co/PANI-PPYR and Fe/PANI-PPYR catalysts is more dominant than a two-electron reaction.In alkaline media,however,a four-electron and a two-electron mechanisms are co-present for the ORR on all the prepared catalysts.Co/PANI-PPYR catalyst also presents good electrocatalytic activity stability for ORR both in acidic and in alkaline media.
基金supported by the National Natural Science Foundation of China (20905038, 20903057, 20974046, 50803027, 20874048 & 20804020)the National Basic Research Program of China (2009CB930600)+1 种基金the Natural Science Foundation of Jiangsu Province (08KJB150011 & 09KJB150007)the Fok Ying-Tong Education Foundation under Grant 111051
文摘Nitrogen-doped carbon nanotubes (N-CNTs)/polyaniline (PANI) composites are developed as an electrode material for biosensors. The morphology, composition, and optical properties of the resulting products were characterized by transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible absorption spectra (UV-vis). Furthermore, N-CNTs/PANI composite was immobilized on the surface of a glassy carbon electrode (GCE) and applied to construct a sensor. The obtained N-CNTs/PANI-modified GCE showed one pair of redox peaks and high catalytic activity for the oxidation of dopamine (DA) in a neutral environment. Differential pulse voltam-mograms results illustrate that the fabricated DA biosensor has high anti-interference ability towards ascorbic acid (AA). In addition, the fabricated biosensor showed superior performances with two wide linear ranges from 1 to 80 μM and from 1.5 to 3.5 mM and a low detection limit of 0.01 μM.
