Herein,we demonstrate the synthesis of bifunctional nickel cobalt selenide@nickel telluride(Ni_(x)Co_(12-x)Se@NiTe)core-shell heterostructures via an electrodeposition approach for overall urea electrolysis and superc...Herein,we demonstrate the synthesis of bifunctional nickel cobalt selenide@nickel telluride(Ni_(x)Co_(12-x)Se@NiTe)core-shell heterostructures via an electrodeposition approach for overall urea electrolysis and supercapacitors.The 3D vertically orientated NiTe dendritic frameworks induce the homogeneous nucleation of 2D Ni_(x)Co_(12-x)Se nanosheet arrays along similar crystal directions and bring a strong interfacial binding between the integrated active components.In particular,the optimized Ni_(6)Co_(6)Se@NiTe with an interface coupling effect works in concert to tune the intrinsic activity.It only needs a low overpotential of 1.33 V to yield a current density of 10 mA cm^(-2)for alkaline urea electrolysis.Meanwhile,the full urea catalysis driven only by Ni_(6)Co_(6)Se@NiTe achieves 10 mA cm^(-2)at a potential of 1.38 V and can approach a constant level of the current response for 40 h.Besides,the integrated Ni_(6)Co_(6)Se@NiTe electrode delivers an enhanced specific capacity(223 mA h g^(-1)at 1 A g^(-1))with a high cycling stability.Consequently,a hybrid asymmetric supercapacitor(HASC)device based on Ni_(6)Co_(6)Se@NiTe exhibits a favorable rate capability and reaches a high energy density of 67.7 Wh kg^(-1)and a power density of 724.8 W kg^(-1)with an exceptional capacity retention of 92.4%after sequential 12000 cycles at 5 A g^(-1).展开更多
Silver/titanium dioxide composite nanoparticles imbedded in polyacrylonitrile (PAN) nanofibers and converted into carbon nanofibers by stabilization and calcination was obtained and tested for capacitive deionization ...Silver/titanium dioxide composite nanoparticles imbedded in polyacrylonitrile (PAN) nanofibers and converted into carbon nanofibers by stabilization and calcination was obtained and tested for capacitive deionization technology. First, the silver ions were converted to metallic silver nanoparticles, through reduction of silver nitrate with dilute solution of PAN. Second, the TiO2 precursor (Titanium Isopropoxide) was added to the solution to form Ag/TiO2 composites imbedded in the PAN polymer solution. Last step involves electrospinning of viscous PAN solution containing silver/TiO2 nanoparticles, thus obtaining PAN nanofibers containing silver/TiO2 nanoparticles. Scanning electron microscopy (SEM) revealed that the diameter of the nanofibers ranged between 50 and 300 nm. Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) showed silver/TiO2 nanoparticles dispersed on the surface of the carbon nanofibers. The obtained fiber was fully characterized by measuring and comparing the FTIR spectra and thermogravimetric analysis (TGA) diagrams of PAN nanofiber with and without imbedded nanoparticles, in order to show the effect of silver/TiO2 nanoparticles on the electrospun fiber properties.展开更多
基金supported by the open fund of the National Defense Key Discipline Laboratory of New Micro/Nano Devices and System Technology,Zhejiang Provincial Natural Science Foundation of China,under Grant No.LY19E020014NSFC(Grant Nos 21303162 and 11604295)
文摘Herein,we demonstrate the synthesis of bifunctional nickel cobalt selenide@nickel telluride(Ni_(x)Co_(12-x)Se@NiTe)core-shell heterostructures via an electrodeposition approach for overall urea electrolysis and supercapacitors.The 3D vertically orientated NiTe dendritic frameworks induce the homogeneous nucleation of 2D Ni_(x)Co_(12-x)Se nanosheet arrays along similar crystal directions and bring a strong interfacial binding between the integrated active components.In particular,the optimized Ni_(6)Co_(6)Se@NiTe with an interface coupling effect works in concert to tune the intrinsic activity.It only needs a low overpotential of 1.33 V to yield a current density of 10 mA cm^(-2)for alkaline urea electrolysis.Meanwhile,the full urea catalysis driven only by Ni_(6)Co_(6)Se@NiTe achieves 10 mA cm^(-2)at a potential of 1.38 V and can approach a constant level of the current response for 40 h.Besides,the integrated Ni_(6)Co_(6)Se@NiTe electrode delivers an enhanced specific capacity(223 mA h g^(-1)at 1 A g^(-1))with a high cycling stability.Consequently,a hybrid asymmetric supercapacitor(HASC)device based on Ni_(6)Co_(6)Se@NiTe exhibits a favorable rate capability and reaches a high energy density of 67.7 Wh kg^(-1)and a power density of 724.8 W kg^(-1)with an exceptional capacity retention of 92.4%after sequential 12000 cycles at 5 A g^(-1).
文摘Silver/titanium dioxide composite nanoparticles imbedded in polyacrylonitrile (PAN) nanofibers and converted into carbon nanofibers by stabilization and calcination was obtained and tested for capacitive deionization technology. First, the silver ions were converted to metallic silver nanoparticles, through reduction of silver nitrate with dilute solution of PAN. Second, the TiO2 precursor (Titanium Isopropoxide) was added to the solution to form Ag/TiO2 composites imbedded in the PAN polymer solution. Last step involves electrospinning of viscous PAN solution containing silver/TiO2 nanoparticles, thus obtaining PAN nanofibers containing silver/TiO2 nanoparticles. Scanning electron microscopy (SEM) revealed that the diameter of the nanofibers ranged between 50 and 300 nm. Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) showed silver/TiO2 nanoparticles dispersed on the surface of the carbon nanofibers. The obtained fiber was fully characterized by measuring and comparing the FTIR spectra and thermogravimetric analysis (TGA) diagrams of PAN nanofiber with and without imbedded nanoparticles, in order to show the effect of silver/TiO2 nanoparticles on the electrospun fiber properties.
