A novel modified electrode was prepared by electrochemicaly cycling scanning the glass carbon electrode covered with a macroporous alumina membrane in a solution containing PPy and PMo 12O 3- 40. The reversibility of ...A novel modified electrode was prepared by electrochemicaly cycling scanning the glass carbon electrode covered with a macroporous alumina membrane in a solution containing PPy and PMo 12O 3- 40. The reversibility of the cyclic voltammograms was improved obviously. The remarkable advantage of the modified electrode was the high sensitivity and favorable electrocatalytic behavior toward NO - 2. The peak current increased linearly with the concentration of NO - 2 in the range of 8.0×10 -7—0.01 mol/L. The detection limit of NO - 2 was 1.0×10 -9 mol/L. The polyoxometalates nanopaticles modified electrode exhibited almost the same electrochemical behavior after 7 d. It is indicated that the PMo 12-PPy/AGCE has a good reproducibility, stability and wide linearity range.展开更多
A bismuth vanadate(BiVO4)photoanode with a cocatalyst consisting of NiFe layered double‐hydroxide(NiFe‐LDH)nanoparticles was fabricated for photoelectrochemical(PEC)water splitting.NiFe‐LDH nanoparticles,which can ...A bismuth vanadate(BiVO4)photoanode with a cocatalyst consisting of NiFe layered double‐hydroxide(NiFe‐LDH)nanoparticles was fabricated for photoelectrochemical(PEC)water splitting.NiFe‐LDH nanoparticles,which can improve light‐absorption capacities and facilitate efficient hole transfer to the surface,were deposited on the surface of the BiVO4 photoanode by a hydrothermal method.All the samples were characterized using X‐ray diffraction,scanning electron microscopy,and diffuse‐reflectance spectroscopy.Linear sweep voltammetry and current‐time plots were used to investigate the PEC activity.The photocurrent response of NiFe‐LDH/BiVO4 at 1.23 V vs the reversible hydrogen electrode was higher than those of Ni(OH)2/BiVO4,Fe(OH)2/BiVO4 and pure BiVO4 electrodes under visible‐light illumination.NiFe‐LDH/BiVO4 also gave a superior PEC hydrogen evolution performance.Furthermore,the stability of the NiFe‐LDH/BiVO4 photoanode was excellent compared with that of the bare BiVO4 photoanode,and offers a novel method for solar‐assisted water splitting.展开更多
The graphene-gold nanoparticles composite film modified glassy carbon electrode （EG- AuNPs/GCE） was prepared by one-step coelectrodeposition and employed for determination of trace mercury in environmental water wit...The graphene-gold nanoparticles composite film modified glassy carbon electrode （EG- AuNPs/GCE） was prepared by one-step coelectrodeposition and employed for determination of trace mercury in environmental water with differential pulse stripping voltammetry. Such a nanostructured composite film combined with the advantages of gold nanoparticles and graphene, can greatly promote the electron-transfer process and increase accumulation abil-ity for Hg（Ⅱ）, leading to a remarkably improved sensitivity. The linear calibration curve ranged from 0.2 μg/L to 30 μg/L for Hg（Ⅱ） and the detection limit （S/N=3） was found to be 0.03 μg/L at a deposition time of 300 s. Moreover, the stablity of the as-prepared electrode and interferences from other substances were evaluated. The modified electrode was successfully applied to the direct detection of Hg（Ⅱ） in real water samples.展开更多
Nanostructured silicon has generated significant excitement for use as the anode material for lithium-ion batteries; however, more effort is needed to produce nanostructured silicon in a scalable fashion and with good...Nanostructured silicon has generated significant excitement for use as the anode material for lithium-ion batteries; however, more effort is needed to produce nanostructured silicon in a scalable fashion and with good performance. Here, we present a direct preparation of porous silicon nanoparticles as a new kind of nanostructured silicon using a novel two-step approach combining controlled boron doping and facile electroless etching. The porous silicon nanoparticles have been successfully used as high performance lithium-ion battery anodes, with capacities around 1,400 mA.h/g achieved at a current rate of 1 A/g, and 1,000 mA.h/g achieved at 2 A/g, and stable operation when combined with reduced graphene oxide and tested over up to 200 cycles. We attribute the overall good performance to the combination of porous silicon that can accommodate large volume change during cycling and provide large surface area accessible to electrolyte, and reduced graphene oxide that can serve as an elastic and electrically conductive matrix for the porous silicon nanoparticles.展开更多
Flexible magnetoelectric （ME） materials have been studied for new applications such as memory, energy harvesters, and magnetic field sensors. Herein, with the widely studied and progressive advantages of ME phenomen...Flexible magnetoelectric （ME） materials have been studied for new applications such as memory, energy harvesters, and magnetic field sensors. Herein, with the widely studied and progressive advantages of ME phenomena in the multiferroic field, we demonstrate a new approach for utilizing flexible ME materials as gate dielectric layers in ME organic field-effect transistors （ME-OFET） that can be used for sensing a magnetic field and extracting the ME properties of the gate dielectric itself. The magnetoelectric nanohybrid gate dielectric layer comprises sandwiched stacks of magnetostrictive CoFe2O4 nanoparticles and a highly piezoelectric poly（vinylidene fluoride-co-trifluoroethylene） layer. While varying the magnetic field applied to the ME gate dielectric, the ME effect in the functional gate dielectric modulates the channel conductance of the ME-OFET owing to a change in the effective gate field. The clear separation of the ME responses in the gate dielectric layer of ME-OFET from those of the other parameters was demonstrated using the AC gate biasing method and enabled the extraction of the ME coefficient of ME materials. Additionally, the device shows high stability after cyclic bending of 10,000 cycles at a banding radius of 1.2 cm. The device has significant potential for not only the extraction of the intrinsic characterization of ME materials but also the sensing of a magnetic field in integrated flexible electronic systems.展开更多
We report a novel chemical vapor deposition （CVD） based strategy to synthesize carbon-coated Fe203 nanoparticles dispersed on graphene sheets （Fe2Og@C@G）. Graphene sheets with high surface area and aspect ratio ar...We report a novel chemical vapor deposition （CVD） based strategy to synthesize carbon-coated Fe203 nanoparticles dispersed on graphene sheets （Fe2Og@C@G）. Graphene sheets with high surface area and aspect ratio are chosen as space restrictor to prevent the sintering and aggregation of nanoparticles during high temperature treatments （800 ℃）. In the resulting nanocomposite, each individual Fe2O3 nanoparticle （5 to 20 nm in diameter） is uniformly coated with a continuous and thin （two to five layers） graphitic carbon shell. Further, the core-shell nanoparticles are evenly distributed on graphene sheets. When used as anode materials for lithium ion batteries, the conductive-additive-free Fe2OB@C@G electrode shows outstanding Li＋ storage properties with large reversible specific capacity （864 mAh/g after 100 cycles）, excellent cyclic stability （120% retention after 100 cycles at 100 mA/g）, high Coulombic efficiency （-99%）, and good rate capability.展开更多
In this work, the intensification of luminol electrochemiluminescence (ECL) by metallic oxide nanoparticles (MONPs), as ZnO, MnO2,In2O3 and TiO2 , under alkaline condition is reported and the related mechanism is stud...In this work, the intensification of luminol electrochemiluminescence (ECL) by metallic oxide nanoparticles (MONPs), as ZnO, MnO2,In2O3 and TiO2 , under alkaline condition is reported and the related mechanism is studied. It is found that all four types of those MONPs exhibit the effect toward the ECL intensification of luminol. Furthermore, the silica sol-gel film is taken to immobilize the MONPs onto the platinum electrodes. The so-obtained modified electrodes also show the enhanced ECL and better signal/noise ratio, as well improved signal stability. Finally, the ECL reagent, luminol, is immobilized together with the MONPs onto the electrode surface to perform as the ECL sensor. On resulting sensors, good linear responses are obtained toward hydrogen peroxide. The mechanism of intensification of luminol ECL by MONPs is discussed in this paper. It is proposed that the ECL intensification can be attributed to the production of reactive oxygen species, as well as the adsorption of luminol on surface of MONPs.展开更多
An NH2+ ion implantation-modified indium tin oxide film was prepared and the implantation of amino groups on the indium tin oxide substrate was verified by X-ray photoelectron spectroscopy analysis.The gold nanopartic...An NH2+ ion implantation-modified indium tin oxide film was prepared and the implantation of amino groups on the indium tin oxide substrate was verified by X-ray photoelectron spectroscopy analysis.The gold nanoparticles attached surface could be obtained by self-assembly of different sized colloidal gold nanoparticles onto the NH2+ ion implantation-modified indium tin oxide surface.By scanning electron microscopy and electrochemical techniques,the as-prepared AuNPs attached NH2+ ion implantation-modified indium tin oxide electrode was characterized and compared with bare indium tin oxide electrode.Using a [Fe(CN)6]3 /[Fe(CN)6]4 redox probe,the increasingly facile heterogeneous electron transfer kinetics resulting from the attached gold nanoparticle arrays was observed.The gold nanoparticle arrays exhibited high catalytic activity toward the electro-oxidation of nitric oxide,which could provide electroanalytical application for nitric oxide sensing.展开更多
The platinum nanoparticles were adsorbed on graphene oxide sheets and played an important role in catalytic reduction of graphene oxide with hydrazine, leading to the formation of graphene-Pt nanoparticles. Because of...The platinum nanoparticles were adsorbed on graphene oxide sheets and played an important role in catalytic reduction of graphene oxide with hydrazine, leading to the formation of graphene-Pt nanoparticles. Because of their good electronic properties, biocompatibility and high surface area, graphene-Pt based composites achieved the direct electron transfer of redox enzyme and maintained their bioactivity well. The graphene-Pt nanocomposites were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction (SAED). The amperometric biosensor fabricated by depositing glucose oxidase over Nafion-solubilized graphene-Pt electrode retained its biocatalytic activity and has offered fast and sensitive glucose quantification.展开更多
An indium tin oxide(ITO)electrode coated with monolayer TiO2/[Ru(phen)2(dC18bpy)] 2+ (phen=1,10-phenanthroline, dC18bpy=4,4′-dioctadecyl-2,2′-bipyridyl)hybrid film(denoted as ITO/TiO2-Ru)has been prepared using the ...An indium tin oxide(ITO)electrode coated with monolayer TiO2/[Ru(phen)2(dC18bpy)] 2+ (phen=1,10-phenanthroline, dC18bpy=4,4′-dioctadecyl-2,2′-bipyridyl)hybrid film(denoted as ITO/TiO2-Ru)has been prepared using the modified Langmuir-Blodgett(LB)method,and the electrocatalytic oxidation of mononucleotide of guanosine 5′-monophosphate(GMP)on an ITO/TiO2-Ru electrode after Pd-photodeposition(denoted as ITO/TiO2-Ru/Pd)has been studied.Atomic force microscopy reveals that the single-layered hybrid film of TiO2 nanosheets/[Ru(phen)2(dC18bpy)] 2+is closely packed at a surface pressure of 25 mN m 1and has a thickness of(3.20±0.5)nm.X-ray photoelectron spectra show the formation of Pd nanoparticles on the surface of hybrid film with radii of 20–200 nm by the reduction of[Pd(NH3)4] 2+ under light irradiation.When it is applied to oxidize GMP,a larger catalytic oxidative current is achieved on the ITO/TiO2-Ru/Pd electrode at the external potential above 700 mV(vs.Ag|AgCl|KCl)in comparison with the naked ITO electrode and ITO/TiO2-Ru electrode.Such a result indicates that the Pd nanoparticles are able to hamper the combination of electron hole pairs and reduce the counterwork of insulating long alkyl chains of amphiphilic Ru(II)complexes,and thus develops the electron transfer efficiency and produces the enhanced redox current.展开更多
文摘A novel modified electrode was prepared by electrochemicaly cycling scanning the glass carbon electrode covered with a macroporous alumina membrane in a solution containing PPy and PMo 12O 3- 40. The reversibility of the cyclic voltammograms was improved obviously. The remarkable advantage of the modified electrode was the high sensitivity and favorable electrocatalytic behavior toward NO - 2. The peak current increased linearly with the concentration of NO - 2 in the range of 8.0×10 -7—0.01 mol/L. The detection limit of NO - 2 was 1.0×10 -9 mol/L. The polyoxometalates nanopaticles modified electrode exhibited almost the same electrochemical behavior after 7 d. It is indicated that the PMo 12-PPy/AGCE has a good reproducibility, stability and wide linearity range.
基金supported by the National Natural Science Foundation of China(21663027,51262028,21261021)the Science and Technology Support Project of Gansu Province(1504GKCA027)+2 种基金the Program for the Young Innovative Talents of Longyuanthe Program for Innovative Research Team(NWNULKQN-15-2)the Undergraduate Academic Innovative Research Team of Northwest Normal University~~
文摘A bismuth vanadate(BiVO4)photoanode with a cocatalyst consisting of NiFe layered double‐hydroxide(NiFe‐LDH)nanoparticles was fabricated for photoelectrochemical(PEC)water splitting.NiFe‐LDH nanoparticles,which can improve light‐absorption capacities and facilitate efficient hole transfer to the surface,were deposited on the surface of the BiVO4 photoanode by a hydrothermal method.All the samples were characterized using X‐ray diffraction,scanning electron microscopy,and diffuse‐reflectance spectroscopy.Linear sweep voltammetry and current‐time plots were used to investigate the PEC activity.The photocurrent response of NiFe‐LDH/BiVO4 at 1.23 V vs the reversible hydrogen electrode was higher than those of Ni(OH)2/BiVO4,Fe(OH)2/BiVO4 and pure BiVO4 electrodes under visible‐light illumination.NiFe‐LDH/BiVO4 also gave a superior PEC hydrogen evolution performance.Furthermore,the stability of the NiFe‐LDH/BiVO4 photoanode was excellent compared with that of the bare BiVO4 photoanode,and offers a novel method for solar‐assisted water splitting.
文摘The graphene-gold nanoparticles composite film modified glassy carbon electrode （EG- AuNPs/GCE） was prepared by one-step coelectrodeposition and employed for determination of trace mercury in environmental water with differential pulse stripping voltammetry. Such a nanostructured composite film combined with the advantages of gold nanoparticles and graphene, can greatly promote the electron-transfer process and increase accumulation abil-ity for Hg（Ⅱ）, leading to a remarkably improved sensitivity. The linear calibration curve ranged from 0.2 μg/L to 30 μg/L for Hg（Ⅱ） and the detection limit （S/N=3） was found to be 0.03 μg/L at a deposition time of 300 s. Moreover, the stablity of the as-prepared electrode and interferences from other substances were evaluated. The modified electrode was successfully applied to the direct detection of Hg（Ⅱ） in real water samples.
文摘Nanostructured silicon has generated significant excitement for use as the anode material for lithium-ion batteries; however, more effort is needed to produce nanostructured silicon in a scalable fashion and with good performance. Here, we present a direct preparation of porous silicon nanoparticles as a new kind of nanostructured silicon using a novel two-step approach combining controlled boron doping and facile electroless etching. The porous silicon nanoparticles have been successfully used as high performance lithium-ion battery anodes, with capacities around 1,400 mA.h/g achieved at a current rate of 1 A/g, and 1,000 mA.h/g achieved at 2 A/g, and stable operation when combined with reduced graphene oxide and tested over up to 200 cycles. We attribute the overall good performance to the combination of porous silicon that can accommodate large volume change during cycling and provide large surface area accessible to electrolyte, and reduced graphene oxide that can serve as an elastic and electrically conductive matrix for the porous silicon nanoparticles.
文摘Flexible magnetoelectric （ME） materials have been studied for new applications such as memory, energy harvesters, and magnetic field sensors. Herein, with the widely studied and progressive advantages of ME phenomena in the multiferroic field, we demonstrate a new approach for utilizing flexible ME materials as gate dielectric layers in ME organic field-effect transistors （ME-OFET） that can be used for sensing a magnetic field and extracting the ME properties of the gate dielectric itself. The magnetoelectric nanohybrid gate dielectric layer comprises sandwiched stacks of magnetostrictive CoFe2O4 nanoparticles and a highly piezoelectric poly（vinylidene fluoride-co-trifluoroethylene） layer. While varying the magnetic field applied to the ME gate dielectric, the ME effect in the functional gate dielectric modulates the channel conductance of the ME-OFET owing to a change in the effective gate field. The clear separation of the ME responses in the gate dielectric layer of ME-OFET from those of the other parameters was demonstrated using the AC gate biasing method and enabled the extraction of the ME coefficient of ME materials. Additionally, the device shows high stability after cyclic bending of 10,000 cycles at a banding radius of 1.2 cm. The device has significant potential for not only the extraction of the intrinsic characterization of ME materials but also the sensing of a magnetic field in integrated flexible electronic systems.
文摘We report a novel chemical vapor deposition （CVD） based strategy to synthesize carbon-coated Fe203 nanoparticles dispersed on graphene sheets （Fe2Og@C@G）. Graphene sheets with high surface area and aspect ratio are chosen as space restrictor to prevent the sintering and aggregation of nanoparticles during high temperature treatments （800 ℃）. In the resulting nanocomposite, each individual Fe2O3 nanoparticle （5 to 20 nm in diameter） is uniformly coated with a continuous and thin （two to five layers） graphitic carbon shell. Further, the core-shell nanoparticles are evenly distributed on graphene sheets. When used as anode materials for lithium ion batteries, the conductive-additive-free Fe2OB@C@G electrode shows outstanding Li＋ storage properties with large reversible specific capacity （864 mAh/g after 100 cycles）, excellent cyclic stability （120% retention after 100 cycles at 100 mA/g）, high Coulombic efficiency （-99%）, and good rate capability.
基金supported by the National Natural Science Foundation of China (20275025 & 20675055)the Natural Science Foundation of Jiangsu Province (BK2009111)Technology Plan of Suzhou (SYJG0901)
文摘In this work, the intensification of luminol electrochemiluminescence (ECL) by metallic oxide nanoparticles (MONPs), as ZnO, MnO2,In2O3 and TiO2 , under alkaline condition is reported and the related mechanism is studied. It is found that all four types of those MONPs exhibit the effect toward the ECL intensification of luminol. Furthermore, the silica sol-gel film is taken to immobilize the MONPs onto the platinum electrodes. The so-obtained modified electrodes also show the enhanced ECL and better signal/noise ratio, as well improved signal stability. Finally, the ECL reagent, luminol, is immobilized together with the MONPs onto the electrode surface to perform as the ECL sensor. On resulting sensors, good linear responses are obtained toward hydrogen peroxide. The mechanism of intensification of luminol ECL by MONPs is discussed in this paper. It is proposed that the ECL intensification can be attributed to the production of reactive oxygen species, as well as the adsorption of luminol on surface of MONPs.
基金supported by the National Nature Science Foundation of China (20211130505)the Fundamental Research Funds for the Central Universities of China
文摘An NH2+ ion implantation-modified indium tin oxide film was prepared and the implantation of amino groups on the indium tin oxide substrate was verified by X-ray photoelectron spectroscopy analysis.The gold nanoparticles attached surface could be obtained by self-assembly of different sized colloidal gold nanoparticles onto the NH2+ ion implantation-modified indium tin oxide surface.By scanning electron microscopy and electrochemical techniques,the as-prepared AuNPs attached NH2+ ion implantation-modified indium tin oxide electrode was characterized and compared with bare indium tin oxide electrode.Using a [Fe(CN)6]3 /[Fe(CN)6]4 redox probe,the increasingly facile heterogeneous electron transfer kinetics resulting from the attached gold nanoparticle arrays was observed.The gold nanoparticle arrays exhibited high catalytic activity toward the electro-oxidation of nitric oxide,which could provide electroanalytical application for nitric oxide sensing.
基金supported by the National Natural Science Foundation of China (Grant No. 21003151)the Fundamental Research Funds for the Central Universities (Grant No. 0400219212)
文摘The platinum nanoparticles were adsorbed on graphene oxide sheets and played an important role in catalytic reduction of graphene oxide with hydrazine, leading to the formation of graphene-Pt nanoparticles. Because of their good electronic properties, biocompatibility and high surface area, graphene-Pt based composites achieved the direct electron transfer of redox enzyme and maintained their bioactivity well. The graphene-Pt nanocomposites were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction (SAED). The amperometric biosensor fabricated by depositing glucose oxidase over Nafion-solubilized graphene-Pt electrode retained its biocatalytic activity and has offered fast and sensitive glucose quantification.
基金supported by the National Natural Science Foundation of China(21073133,20843007,20471043)Zhejiang Provincial Natural Science Foundation of China(Y5100283,Y4090248,Y4080177)Wenzhou University Foundation(2007L019)
文摘An indium tin oxide(ITO)electrode coated with monolayer TiO2/[Ru(phen)2(dC18bpy)] 2+ (phen=1,10-phenanthroline, dC18bpy=4,4′-dioctadecyl-2,2′-bipyridyl)hybrid film(denoted as ITO/TiO2-Ru)has been prepared using the modified Langmuir-Blodgett(LB)method,and the electrocatalytic oxidation of mononucleotide of guanosine 5′-monophosphate(GMP)on an ITO/TiO2-Ru electrode after Pd-photodeposition(denoted as ITO/TiO2-Ru/Pd)has been studied.Atomic force microscopy reveals that the single-layered hybrid film of TiO2 nanosheets/[Ru(phen)2(dC18bpy)] 2+is closely packed at a surface pressure of 25 mN m 1and has a thickness of(3.20±0.5)nm.X-ray photoelectron spectra show the formation of Pd nanoparticles on the surface of hybrid film with radii of 20–200 nm by the reduction of[Pd(NH3)4] 2+ under light irradiation.When it is applied to oxidize GMP,a larger catalytic oxidative current is achieved on the ITO/TiO2-Ru/Pd electrode at the external potential above 700 mV(vs.Ag|AgCl|KCl)in comparison with the naked ITO electrode and ITO/TiO2-Ru electrode.Such a result indicates that the Pd nanoparticles are able to hamper the combination of electron hole pairs and reduce the counterwork of insulating long alkyl chains of amphiphilic Ru(II)complexes,and thus develops the electron transfer efficiency and produces the enhanced redox current.
