An electrochemically reduced graphene oxide sample, ERGO_0.8v, was prepared by electrochemical reduction of graphene oxide （GO） at -0.8 V, which shows unique electrocatalytic activity toward tetracycline （TTC） det...An electrochemically reduced graphene oxide sample, ERGO_0.8v, was prepared by electrochemical reduction of graphene oxide （GO） at -0.8 V, which shows unique electrocatalytic activity toward tetracycline （TTC） detection compared to the ERGO-12v （GO applied to a negative potential of-1.2 V）, GO, chemically reduced GO （CRGO）-modified glassy carbon electrode （GC） and bare GC electrodes. The redox peaks of TTC on an ERGO-0.8v-modifled glass carbon electrode （GC/ERGO-0.8v） were within 0-0.5 V in a pH 3.0 buffer solution with the oxidation peak current correlating well with TTC concentration over a wide range from 0.1 to 160 mg/L Physical characterizations with Fourier transform infrared （FT-IR）, Raman, and X-ray photoelectron spectroscopies （XPS） demonstrated that the oxygen-containing functional groups on GO diminished after the electrochemical reduction at -0.8 V, yet still existed in large amounts, and the defect density changed as new sp2 domains were formed. These changes demonstrated that this adjustment in the number of oxygen-containing groups might be the main factor affecting the electrocatalytic behavior of ERGO. Additionally, the defect density and sp2 domains also exert a profound influence on this behavior. A possible mechanism for the TTC redox reaction at the GC/ERGO-0.8v electrode is also presented. This work suggests that the electrochemical reduction is an effective method to establish new catalytic activities of GO by setting appropriate parameters.展开更多
An electrochemical method based on a directly electrochemically reduced graphene oxide （ERGO） film coated on a glassy carbon electrode （GCE） was developed for the rapid and convenient determination of rutin in pla...An electrochemical method based on a directly electrochemically reduced graphene oxide （ERGO） film coated on a glassy carbon electrode （GCE） was developed for the rapid and convenient determination of rutin in plasma. ERGO was modified on the surface of GCE by one-step electro-deposition method. Electrochemical behavior of rutin on ERGO/GCE indicated that rutin underwent a surface-controlled quasi-reversible process and the electrochemical parameters such as charge transfer coefficient （α）, electron transfer number （n） and electrode reaction standard rate constant （ks） were 0.53, 2 and 3.4 s -1, respectively. The electrochemical sensor for rutin in plasma provided a wide linear response range of 4.70 × 10 ^-7 1.25 × 10^-5 M with the detection limit （s/n=3） of 1.84 × 10^-8 M. The assay was success- fully used to the pharmacokinetic study of rutin. The pharmacokinetic parameters such as elimination rate half-life （t1/2）, area under curve （AUC）, and plasma clearance （CL） were calculated to be 3.345 ± 0.647 rain, 5750 ±656.0 μg min/mL, and 5.891± 0.458 mL/min/kg, respectively. The proposed method utilized a small sample volume of 10 μL and had no complicated sample pretreatment （without deproteinization）, which was simple, eco-friendly, and time- and cost-efficient for rutin pharmacokinetic studies.展开更多
A reduced graphene oxide/Ni(OH)2 composite with excellent supercapacitive performance was synthesized by a facile hydrothermal route without organic solvents or templates used.XRD and SEM results reveal that the nicke...A reduced graphene oxide/Ni(OH)2 composite with excellent supercapacitive performance was synthesized by a facile hydrothermal route without organic solvents or templates used.XRD and SEM results reveal that the nickel hydroxide,which crystallizes into hexagonal β-Ni(OH)2 nanoflakes with a diameter less than 200 nm and a thickness of about 10 nm,is well combined with the reduced graphene oxide sheets.Electrochemical performance of the synthesized composite as an electrode material was investigated by cyclic voltammetry,electrochemical impedance spectroscopy and galvanostatic charge/discharge measurements.Its specific capacitance is determined to be 1672 F/g at a scan rate of 2 mV/s,and 696 F/g at a high scan rate of 50 mV/s.After 2000 cycles at a current density of 10 A/g,the composite exhibits a specific capacitance of 969 F/g,retaining about 86% of its initial capacitance.The composite delivers a high energy density of 83.6 W·h/kg at a power density of 1.0 kW/kg.The excellent supercapacitive performance along with the easy synthesis method allows the synthesized composite to be promising for supercapacitor applications.展开更多
A simple and reliable strategy was proposed to engineer the glutathione grafted graphene oxide/ZnO nanocomposite(glutathione-GO/ZnO)as electrode material for the high-performance piroxicam sensor.The prepared glutathi...A simple and reliable strategy was proposed to engineer the glutathione grafted graphene oxide/ZnO nanocomposite(glutathione-GO/ZnO)as electrode material for the high-performance piroxicam sensor.The prepared glutathione-GO/ZnO nanocomposite was well characterized by X-ray diffraction(XRD),Fourier transform infrared spectrum(FTIR),X-ray photoelectron spectroscopy(XPS),field emission scanning electron microscopy(FE-SEM),cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS)and differential pulse voltammetry(DPV).The novel nanocomposite modified electrode showed the highest electrocatalytic activity towards piroxicam(oxidation potential is 0.52 V).Under controlled experimental parameters,the proposed sensor exhibited good linear responses to piroxicam concentrations ranging from 0.1 to 500 μM.The detection limit and sensitivity were calculated as 1.8 μM and 0.2 μA/μM·cm^(2),respectively.Moreover,it offered excellent selectivity,reproducibility,and long-term stability and can effectively ignore the interfering candidates commonly existing in the pharmaceutical tablets and human fluids even at a higher concentration.Finally,the reported sensor was successfully employed to the direct determination of piroxicam in practical samples.展开更多
Poly(3,4-ethylenedioxyethiophene)-polystyrene sulfonic acid(PEDOT:PSS)/polyallyl dimethyl ammonium chloride modified reduced graphene oxide(PDDA-rGO)was layer by layer self-assembled on the cotton fiber.The surface mo...Poly(3,4-ethylenedioxyethiophene)-polystyrene sulfonic acid(PEDOT:PSS)/polyallyl dimethyl ammonium chloride modified reduced graphene oxide(PDDA-rGO)was layer by layer self-assembled on the cotton fiber.The surface morphology and electric property was investigated.The results confirmed the dense membrane of PEDOT:PSS and the lamellar structure of PDDA-rGO on the fibers.It has excellent electrical conductivity and mechanical properties.The fiber based electrochemical transistor(FECTs)prepared by the composite conductive fiber has a maximum output current of 8.7 mA,a transconductance peak of 10 mS,an on time of 1.37 s,an off time of 1.6 s and excellent switching stability.Most importantly,the devices by layer by layer self-assembly technology opens a path for the true integration of organic electronics with traditional textile technologies and materials,laying the foundation for their later widespread application.展开更多
The fine control of doping levels in graphene materials such as reduced graphene oxide(RGO)is important to properly manipulate their ambipolar transport characteristics for various device applications.However,conventi...The fine control of doping levels in graphene materials such as reduced graphene oxide(RGO)is important to properly manipulate their ambipolar transport characteristics for various device applications.However,conventional doping methods involve complex chemical reactions,large-scale doping processes,and poor stability.Herein,a simple and controllable electrochemical doping treatment(EDT),performed via the conductive channels created at the RGO surface by the application of an electric field,is introduced to tailor the electrical properties of RGO films.X-ray photoelectron spectroscopy and Raman spectroscopy measurements are performed to detect the presence of Ni atoms in RGO films after the EDT(EDT-RGO).Then,EDT-RGO field-effect transistors(FETs)are fabricated with different doping areas(0 to 100%fractional area)on the RGO active channel to investigate the effect and selective-area doping capability of the EDT.Owing to p-type doping compensation by the intercalated Ni atoms,the electron mobility of the EDT-RGO FET decreases from 1.40 to 0.12 cm2 V-1s-1 compared with that of the undoped RGO-FET,leading to the conversion from ambipolar to unipolar p-type transfer characteristics.展开更多
The sandwich-like structure of reduced graphene oxide/polyaniline （RGO/PANI） hybrid electrode was prepared by electrochemical deposition. Both the voltage windows and electrolytes for electrochemical deposition of P...The sandwich-like structure of reduced graphene oxide/polyaniline （RGO/PANI） hybrid electrode was prepared by electrochemical deposition. Both the voltage windows and electrolytes for electrochemical deposition of PANI and RGO were optimized. In the composites, PANI nanofibers were anchored on the surface of the RGO sheets, which avoids the re-stacking of neighboring sheets. The R（;O/PANI composite electrode shows a high specific capacitance of 466 F/g at 2 mA/cm2 than that of previously reported RGO/PANI composites. Asymmetric flexible supercapacitors applying RGO/PANI as positive electrode and carbon fiber cloth as negative electrode can be cycled reversibly in the high-voltage region of 0-1.6 V and displays intriguing performance with a maximum specific capacitance of 35.5 mF cm^-2. Also, it delivers a high energy density of 45.5 mW h cm^-2 at power density of 1250 mW cm^-2. Furthermore, the asymmetric device exhibits an excellent long cycle life with 97.6Z initial capacitance retention after 5000 cycles. Such composite electrode has a great potential for applications in flexible electronics, roll-up display, and wearable devices.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.展开更多
In this work, a facile, one-pot route has been applied to synthesize nanohybrids based on mixed oxide NiFe2O4 and reduced graphene oxide （rGO）. The hybrid is constructed by nanosized NiFe2O4 crystals confined by few...In this work, a facile, one-pot route has been applied to synthesize nanohybrids based on mixed oxide NiFe2O4 and reduced graphene oxide （rGO）. The hybrid is constructed by nanosized NiFe2O4 crystals confined by few- layered rGO sheets. The formation mechanism and microstructure of the hybrids have been clarified by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. Electrochemical tests show that the performance of NiFe2O4 can be considerably improved by rGO incorporation. The performance improvement can be attributed to the two-dimensional conductive channels and the unique hybrid structure rGO constructed. The easy synthesis and good electrochemical performance of NiFe2O4/rGO hybrid make it a promising anode material for Li-ion batteries.展开更多
An innovative molecularly imprinted electrochemical sensor was fabricated based on reduced graphene oxide （RGO） and gold nanocomposite （Au） for rapid detection of vincristine （VCR）. The RGO-Au composite membrane...An innovative molecularly imprinted electrochemical sensor was fabricated based on reduced graphene oxide （RGO） and gold nanocomposite （Au） for rapid detection of vincristine （VCR）. The RGO-Au composite membrane was obtained via direct one-step electrodeposition technique of graphene oxide （GO） and chloroauric acid （HAuCl4） on the surface of a glassy carbon electrode （GCE） by means of cyclic voltammetry （CV） in the potential range be- tween -1.5 and 0.6 V in phosphate buffer solution （PBS） of pH 9.18, which is capable of effectively utilizing its superior electrical conductivity, larger specific surface area due to its synergistic effect between RGO and Au. The molecularly imprinted polymers （MIPs） were synthesized on the RGO-Au modified glassy carbon electrode surface with VCR as the template molecular, methyl acrylic acid （MAA） as the functional monomer, and ethylene glycol maleic rosinate acrylate （EGMRA） as a cross-linker. The performance of the sensor was investigated by cyclic voltammetry （CV）, differential pulse voltammetry （DPV） and electrochemical impedance spectroscopy （EIS） in de- tail. Under the optimum conditions, the fabricated sensor exhibited a linear relationship between oxidation peak current and VCR concentration over the range of 5.0×10 8 5.0×10^-6 mol.L l with a correlation coefficient of 0.9952 and a detection limit （S/N=3） of 2.6×10 8 mol.L^-1. The results indicated that the imprinted polymer films exhibited an excellent selectivity for VCR. The imprinted sensor was successfully used to determine VCR in real samples with recoveries of 90%-- 120% by using the standard addition method.展开更多
In_(2)O_(3)is an effective electrocatalyst to convert CO_(2)to formic acid(HCOOH),but its inherent poor electrical conductivity limits the efficient charge transfer during the reaction.Additionally,the tendency of In_...In_(2)O_(3)is an effective electrocatalyst to convert CO_(2)to formic acid(HCOOH),but its inherent poor electrical conductivity limits the efficient charge transfer during the reaction.Additionally,the tendency of In_(2)O_(3)particles to agglomerate during synthesis further limits the exposure of active sites.Here we address these issues by leveraging the template effect of graphene oxide and employing InBDC as a self-sacrificing template for the pyrolysis synthesis of In_(2)O_(3)@C.The resulting In_(2)O_(3)@C/rGO-600 material features In_(2)O_(3)@C nanocubes uniformly anchored on a support of reduced graphene oxide(rGO),significantly enhancing the active sites exposure.The conductive rGO network facilitates charge transfer during electrocatalysis,and the presence of oxygen vacancies generated during pyrolysis,combined with the strong electron-donating ability of rGO,enhances the adsorption and activation of CO_(2).In performance evaluation,In_(2)O_(3)@C/rGO-600 exhibits a remarkable HCOOH Faradaic efficiency exceeding 94.0%over a broad potential window of−0.7 to−1.0 V(vs.reversible hydrogen electrode(RHE)),with the highest value of 97.9%at−0.9 V(vs.RHE)in a H-cell.Moreover,the material demonstrates an excellent cathodic energy efficiency of 71.6%at−0.7 V(vs.RHE).The study underscores the efficacy of uniformly anchoring metal oxide nanoparticles onto rGO for enhancing the electrocatalytic CO_(2)reduction performance of materials.展开更多
In this paper, a simple and reliable fabrication method about electrochemically reduced graphene oxide （ERGNO）-prussian blue （PB） nanocomposite was proposed for determination of guanine. Due to its unique struc- t...In this paper, a simple and reliable fabrication method about electrochemically reduced graphene oxide （ERGNO）-prussian blue （PB） nanocomposite was proposed for determination of guanine. Due to its unique struc- tural, physical and chemical properties, ERGNO, which was fabricated on the carbon paste electrode （CPE） before- hand through electrochemical reduction of graphene oxide, was selected as a compatible precursor for next-step PB electrodeposition. Electrochemical behaviors of the resulted PB/ERGNO/CPE were investigated by electrochemical impedance spectroscopy （EIS）, cyclic voltammetry （CV） and differential pulse voltammetry （DPV）. The electro- chemical results showed that PB/ERGNO/CPE exhibited good electrochemical performances. The electrocatalytic results of guanine further illustrated that graphene prompted the electrocatalytie ability of PB via the redox shift between PB and prussian yellow （PY） in the potential range from 0.5 to 1.2 V, which has not been widely adopted in the PB based electrochemical sensors. The detection limit of guanine could be calculated to be 1.0 × 10^-8 mol/L. It means this PB/ERGNO/CPE platform is quite sensitive and can be readily applied in biosensor field.展开更多
High density and uniform distribution of the gold nanoparticles functionalized single-stranded DNA modified reduced graphene oxide nanocomposites were obtained by non-covalent interaction.The positive gold nanoparticl...High density and uniform distribution of the gold nanoparticles functionalized single-stranded DNA modified reduced graphene oxide nanocomposites were obtained by non-covalent interaction.The positive gold nanoparticles prepared by phase inversion method exhibited good dimensional homogeneity and dispersibility,which could readily combine with single-stranded DNA modified reduced graphene oxide nanocomposites by electrostatic interactions.The modification of single-stranded DNA endowed the reduced graphene oxide with favorable biocompatibility and provided the preferable surface with negative charge for further assembling of gold nanoparticles to obtain gold nanoparticles/single-stranded DNA modified reduced graphene oxide nanocomposites with better conductivity,larger specific surface area,biocompatibility and electrocatalytic characteristics.The as-prepared nanocomposites were applied as substrates for the construction of cholesterol oxidase modified electrode and well realized the direct electron transfer between the enzyme and electrode.The modified gold nanoparticles could further catalyze the products of cholesterol oxidation catalyzed by cholesterol oxidase,which was beneficial to the enzyme-catalyzed reaction.The as-fabricated bioelectrode exhibited excellent electrocatalytic performance for the cholesterol with a linear range of 7.5–280.5μmol·L^(−1),a low detection limit of 2.1μmol·L^(−1),good stability and reproducibility.Moreover,the electrochemical biosensor showed good selectivity and acceptable accuracy for the detection of cholesterol in human serum samples.展开更多
In this paper,we present a novel,reliable and sensitive electrochemical sensor for the determination of paracetamol based on hollow carbon Co3O4 nanosheets/reduced graphene oxide composite(Co3O4/r-GO).The Co3O4/r-GO w...In this paper,we present a novel,reliable and sensitive electrochemical sensor for the determination of paracetamol based on hollow carbon Co3O4 nanosheets/reduced graphene oxide composite(Co3O4/r-GO).The Co3O4/r-GO was prepared via a rapid one-step microwave solvothermal process.Some series of techniques that included scanning electron microscopy,X-ray diffraction and Raman were carried out to characterize the morphology and structure of as-prepared materials.Most importantly,the developed electrochemical sensor exhibited a wide linear range of 0.05 to 900.0μM and a low detection limit of 14.0 nM(S/N=3)by using differential pulse voltammetry.Furthermore,the selectivity,repeatability,stability and practical applicability were further studied with satisfactory results.展开更多
基金supported by the National Natural Science Foundation of China(21007033)the Fundamental Research Funds of Shandong University(2015JC017)~~
文摘An electrochemically reduced graphene oxide sample, ERGO_0.8v, was prepared by electrochemical reduction of graphene oxide （GO） at -0.8 V, which shows unique electrocatalytic activity toward tetracycline （TTC） detection compared to the ERGO-12v （GO applied to a negative potential of-1.2 V）, GO, chemically reduced GO （CRGO）-modified glassy carbon electrode （GC） and bare GC electrodes. The redox peaks of TTC on an ERGO-0.8v-modifled glass carbon electrode （GC/ERGO-0.8v） were within 0-0.5 V in a pH 3.0 buffer solution with the oxidation peak current correlating well with TTC concentration over a wide range from 0.1 to 160 mg/L Physical characterizations with Fourier transform infrared （FT-IR）, Raman, and X-ray photoelectron spectroscopies （XPS） demonstrated that the oxygen-containing functional groups on GO diminished after the electrochemical reduction at -0.8 V, yet still existed in large amounts, and the defect density changed as new sp2 domains were formed. These changes demonstrated that this adjustment in the number of oxygen-containing groups might be the main factor affecting the electrocatalytic behavior of ERGO. Additionally, the defect density and sp2 domains also exert a profound influence on this behavior. A possible mechanism for the TTC redox reaction at the GC/ERGO-0.8v electrode is also presented. This work suggests that the electrochemical reduction is an effective method to establish new catalytic activities of GO by setting appropriate parameters.
基金support of the Project of Science and Technology Agency of Gansu (No.1208RTZA211) and Lanzhou(Nos. 2012-2-67 and 2013-4-75)
文摘An electrochemical method based on a directly electrochemically reduced graphene oxide （ERGO） film coated on a glassy carbon electrode （GCE） was developed for the rapid and convenient determination of rutin in plasma. ERGO was modified on the surface of GCE by one-step electro-deposition method. Electrochemical behavior of rutin on ERGO/GCE indicated that rutin underwent a surface-controlled quasi-reversible process and the electrochemical parameters such as charge transfer coefficient （α）, electron transfer number （n） and electrode reaction standard rate constant （ks） were 0.53, 2 and 3.4 s -1, respectively. The electrochemical sensor for rutin in plasma provided a wide linear response range of 4.70 × 10 ^-7 1.25 × 10^-5 M with the detection limit （s/n=3） of 1.84 × 10^-8 M. The assay was success- fully used to the pharmacokinetic study of rutin. The pharmacokinetic parameters such as elimination rate half-life （t1/2）, area under curve （AUC）, and plasma clearance （CL） were calculated to be 3.345 ± 0.647 rain, 5750 ±656.0 μg min/mL, and 5.891± 0.458 mL/min/kg, respectively. The proposed method utilized a small sample volume of 10 μL and had no complicated sample pretreatment （without deproteinization）, which was simple, eco-friendly, and time- and cost-efficient for rutin pharmacokinetic studies.
基金Project(KJ2012A045) supported by the Natural Science Foundation of Education Commission of Anhui Province,China
文摘A reduced graphene oxide/Ni(OH)2 composite with excellent supercapacitive performance was synthesized by a facile hydrothermal route without organic solvents or templates used.XRD and SEM results reveal that the nickel hydroxide,which crystallizes into hexagonal β-Ni(OH)2 nanoflakes with a diameter less than 200 nm and a thickness of about 10 nm,is well combined with the reduced graphene oxide sheets.Electrochemical performance of the synthesized composite as an electrode material was investigated by cyclic voltammetry,electrochemical impedance spectroscopy and galvanostatic charge/discharge measurements.Its specific capacitance is determined to be 1672 F/g at a scan rate of 2 mV/s,and 696 F/g at a high scan rate of 50 mV/s.After 2000 cycles at a current density of 10 A/g,the composite exhibits a specific capacitance of 969 F/g,retaining about 86% of its initial capacitance.The composite delivers a high energy density of 83.6 W·h/kg at a power density of 1.0 kW/kg.The excellent supercapacitive performance along with the easy synthesis method allows the synthesized composite to be promising for supercapacitor applications.
基金supported by SERB(Science and Engineering Research Board),New Delhi,India[File.No:EMR/2014/000020].
文摘A simple and reliable strategy was proposed to engineer the glutathione grafted graphene oxide/ZnO nanocomposite(glutathione-GO/ZnO)as electrode material for the high-performance piroxicam sensor.The prepared glutathione-GO/ZnO nanocomposite was well characterized by X-ray diffraction(XRD),Fourier transform infrared spectrum(FTIR),X-ray photoelectron spectroscopy(XPS),field emission scanning electron microscopy(FE-SEM),cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS)and differential pulse voltammetry(DPV).The novel nanocomposite modified electrode showed the highest electrocatalytic activity towards piroxicam(oxidation potential is 0.52 V).Under controlled experimental parameters,the proposed sensor exhibited good linear responses to piroxicam concentrations ranging from 0.1 to 500 μM.The detection limit and sensitivity were calculated as 1.8 μM and 0.2 μA/μM·cm^(2),respectively.Moreover,it offered excellent selectivity,reproducibility,and long-term stability and can effectively ignore the interfering candidates commonly existing in the pharmaceutical tablets and human fluids even at a higher concentration.Finally,the reported sensor was successfully employed to the direct determination of piroxicam in practical samples.
基金Funded by the Key R&D Program of the Science and Technology Department of Hubei Province(No.2022BCE008)。
文摘Poly(3,4-ethylenedioxyethiophene)-polystyrene sulfonic acid(PEDOT:PSS)/polyallyl dimethyl ammonium chloride modified reduced graphene oxide(PDDA-rGO)was layer by layer self-assembled on the cotton fiber.The surface morphology and electric property was investigated.The results confirmed the dense membrane of PEDOT:PSS and the lamellar structure of PDDA-rGO on the fibers.It has excellent electrical conductivity and mechanical properties.The fiber based electrochemical transistor(FECTs)prepared by the composite conductive fiber has a maximum output current of 8.7 mA,a transconductance peak of 10 mS,an on time of 1.37 s,an off time of 1.6 s and excellent switching stability.Most importantly,the devices by layer by layer self-assembly technology opens a path for the true integration of organic electronics with traditional textile technologies and materials,laying the foundation for their later widespread application.
基金supported financially by the National Research Foundation of Korea(NRF)(No.2016R1A3B1908249).
文摘The fine control of doping levels in graphene materials such as reduced graphene oxide(RGO)is important to properly manipulate their ambipolar transport characteristics for various device applications.However,conventional doping methods involve complex chemical reactions,large-scale doping processes,and poor stability.Herein,a simple and controllable electrochemical doping treatment(EDT),performed via the conductive channels created at the RGO surface by the application of an electric field,is introduced to tailor the electrical properties of RGO films.X-ray photoelectron spectroscopy and Raman spectroscopy measurements are performed to detect the presence of Ni atoms in RGO films after the EDT(EDT-RGO).Then,EDT-RGO field-effect transistors(FETs)are fabricated with different doping areas(0 to 100%fractional area)on the RGO active channel to investigate the effect and selective-area doping capability of the EDT.Owing to p-type doping compensation by the intercalated Ni atoms,the electron mobility of the EDT-RGO FET decreases from 1.40 to 0.12 cm2 V-1s-1 compared with that of the undoped RGO-FET,leading to the conversion from ambipolar to unipolar p-type transfer characteristics.
基金supported by the Qing Lan Project of Jiangsu Provincethe Natural Science Foundation of Jiangsu Province (BK20161289)+4 种基金the Natural Science Foundation of Higher Education of Jiangsu Province (17KJB610009)the Research Innovation Program for College Graduates and Students of Jiangsu Province (KYZZ15 0043)the Foundation of Nantong Vocational University (1512102)the College Students Innovation and Entrepreneurship Training Program of Jiangsu Province (201612684001Y)333 Talents Program of Jiangsu Province (BRA2016195)
文摘The sandwich-like structure of reduced graphene oxide/polyaniline （RGO/PANI） hybrid electrode was prepared by electrochemical deposition. Both the voltage windows and electrolytes for electrochemical deposition of PANI and RGO were optimized. In the composites, PANI nanofibers were anchored on the surface of the RGO sheets, which avoids the re-stacking of neighboring sheets. The R（;O/PANI composite electrode shows a high specific capacitance of 466 F/g at 2 mA/cm2 than that of previously reported RGO/PANI composites. Asymmetric flexible supercapacitors applying RGO/PANI as positive electrode and carbon fiber cloth as negative electrode can be cycled reversibly in the high-voltage region of 0-1.6 V and displays intriguing performance with a maximum specific capacitance of 35.5 mF cm^-2. Also, it delivers a high energy density of 45.5 mW h cm^-2 at power density of 1250 mW cm^-2. Furthermore, the asymmetric device exhibits an excellent long cycle life with 97.6Z initial capacitance retention after 5000 cycles. Such composite electrode has a great potential for applications in flexible electronics, roll-up display, and wearable devices.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.
基金supported by the National Basic Research Program of China (No.2013CB934001)the Fundamental Research Funds for the Central Universities (No.2014XZZX002-03)+2 种基金the National Natural Science Foundation of China (No.51101139)Key Science and Technology Innovation Team of Zhejiang Province under Grant No.2010R50013Program for Innovative Research Team in University of Ministry of Education of China (No.IRT13037)
文摘In this work, a facile, one-pot route has been applied to synthesize nanohybrids based on mixed oxide NiFe2O4 and reduced graphene oxide （rGO）. The hybrid is constructed by nanosized NiFe2O4 crystals confined by few- layered rGO sheets. The formation mechanism and microstructure of the hybrids have been clarified by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. Electrochemical tests show that the performance of NiFe2O4 can be considerably improved by rGO incorporation. The performance improvement can be attributed to the two-dimensional conductive channels and the unique hybrid structure rGO constructed. The easy synthesis and good electrochemical performance of NiFe2O4/rGO hybrid make it a promising anode material for Li-ion batteries.
文摘An innovative molecularly imprinted electrochemical sensor was fabricated based on reduced graphene oxide （RGO） and gold nanocomposite （Au） for rapid detection of vincristine （VCR）. The RGO-Au composite membrane was obtained via direct one-step electrodeposition technique of graphene oxide （GO） and chloroauric acid （HAuCl4） on the surface of a glassy carbon electrode （GCE） by means of cyclic voltammetry （CV） in the potential range be- tween -1.5 and 0.6 V in phosphate buffer solution （PBS） of pH 9.18, which is capable of effectively utilizing its superior electrical conductivity, larger specific surface area due to its synergistic effect between RGO and Au. The molecularly imprinted polymers （MIPs） were synthesized on the RGO-Au modified glassy carbon electrode surface with VCR as the template molecular, methyl acrylic acid （MAA） as the functional monomer, and ethylene glycol maleic rosinate acrylate （EGMRA） as a cross-linker. The performance of the sensor was investigated by cyclic voltammetry （CV）, differential pulse voltammetry （DPV） and electrochemical impedance spectroscopy （EIS） in de- tail. Under the optimum conditions, the fabricated sensor exhibited a linear relationship between oxidation peak current and VCR concentration over the range of 5.0×10 8 5.0×10^-6 mol.L l with a correlation coefficient of 0.9952 and a detection limit （S/N=3） of 2.6×10 8 mol.L^-1. The results indicated that the imprinted polymer films exhibited an excellent selectivity for VCR. The imprinted sensor was successfully used to determine VCR in real samples with recoveries of 90%-- 120% by using the standard addition method.
基金Joint Key Program of National Natural Science Foundation of China(No.U22B20147).
文摘In_(2)O_(3)is an effective electrocatalyst to convert CO_(2)to formic acid(HCOOH),but its inherent poor electrical conductivity limits the efficient charge transfer during the reaction.Additionally,the tendency of In_(2)O_(3)particles to agglomerate during synthesis further limits the exposure of active sites.Here we address these issues by leveraging the template effect of graphene oxide and employing InBDC as a self-sacrificing template for the pyrolysis synthesis of In_(2)O_(3)@C.The resulting In_(2)O_(3)@C/rGO-600 material features In_(2)O_(3)@C nanocubes uniformly anchored on a support of reduced graphene oxide(rGO),significantly enhancing the active sites exposure.The conductive rGO network facilitates charge transfer during electrocatalysis,and the presence of oxygen vacancies generated during pyrolysis,combined with the strong electron-donating ability of rGO,enhances the adsorption and activation of CO_(2).In performance evaluation,In_(2)O_(3)@C/rGO-600 exhibits a remarkable HCOOH Faradaic efficiency exceeding 94.0%over a broad potential window of−0.7 to−1.0 V(vs.reversible hydrogen electrode(RHE)),with the highest value of 97.9%at−0.9 V(vs.RHE)in a H-cell.Moreover,the material demonstrates an excellent cathodic energy efficiency of 71.6%at−0.7 V(vs.RHE).The study underscores the efficacy of uniformly anchoring metal oxide nanoparticles onto rGO for enhancing the electrocatalytic CO_(2)reduction performance of materials.
文摘In this paper, a simple and reliable fabrication method about electrochemically reduced graphene oxide （ERGNO）-prussian blue （PB） nanocomposite was proposed for determination of guanine. Due to its unique struc- tural, physical and chemical properties, ERGNO, which was fabricated on the carbon paste electrode （CPE） before- hand through electrochemical reduction of graphene oxide, was selected as a compatible precursor for next-step PB electrodeposition. Electrochemical behaviors of the resulted PB/ERGNO/CPE were investigated by electrochemical impedance spectroscopy （EIS）, cyclic voltammetry （CV） and differential pulse voltammetry （DPV）. The electro- chemical results showed that PB/ERGNO/CPE exhibited good electrochemical performances. The electrocatalytic results of guanine further illustrated that graphene prompted the electrocatalytie ability of PB via the redox shift between PB and prussian yellow （PY） in the potential range from 0.5 to 1.2 V, which has not been widely adopted in the PB based electrochemical sensors. The detection limit of guanine could be calculated to be 1.0 × 10^-8 mol/L. It means this PB/ERGNO/CPE platform is quite sensitive and can be readily applied in biosensor field.
基金support from the National Natural Science Foundation of China(Grant Nos.51773085,52071171)the Liaoning Province Doctor Start-up Fund(Grant No.20170520282)+8 种基金the Doctor Start-up Fund of Liaoning University(Grant No.a280008020)research fund pre-declaration project of Liaoning University(Grant No.LDGY2019001)teaching reform research project of Liaoning University(Grant Nos.JG2018YB20,LNDXJG20183013,JG2020ZSWT022)Liaoning Revitalization Talents Program-Pan Deng Scholars(Grant No.XLYC1802005)Liaoning BaiQianWan Talents Program(Grant No.LNBQW2018B0048)Natural Science Fund of Liaoning Province for Excellent Young Scholars(Grant No.2019-YQ-04)Key Project of Scientific Research of the Education Department of Liaoning Province(Grant No.LZD201902)the Young Scientific and Technological Talents Project of the Department of Education of Liaoning Province(Grant Nos.LQN201903 and LQN202008)the Foundation for Young Scholars of Liaoning University(Grant No.LDQN2019007).
文摘High density and uniform distribution of the gold nanoparticles functionalized single-stranded DNA modified reduced graphene oxide nanocomposites were obtained by non-covalent interaction.The positive gold nanoparticles prepared by phase inversion method exhibited good dimensional homogeneity and dispersibility,which could readily combine with single-stranded DNA modified reduced graphene oxide nanocomposites by electrostatic interactions.The modification of single-stranded DNA endowed the reduced graphene oxide with favorable biocompatibility and provided the preferable surface with negative charge for further assembling of gold nanoparticles to obtain gold nanoparticles/single-stranded DNA modified reduced graphene oxide nanocomposites with better conductivity,larger specific surface area,biocompatibility and electrocatalytic characteristics.The as-prepared nanocomposites were applied as substrates for the construction of cholesterol oxidase modified electrode and well realized the direct electron transfer between the enzyme and electrode.The modified gold nanoparticles could further catalyze the products of cholesterol oxidation catalyzed by cholesterol oxidase,which was beneficial to the enzyme-catalyzed reaction.The as-fabricated bioelectrode exhibited excellent electrocatalytic performance for the cholesterol with a linear range of 7.5–280.5μmol·L^(−1),a low detection limit of 2.1μmol·L^(−1),good stability and reproducibility.Moreover,the electrochemical biosensor showed good selectivity and acceptable accuracy for the detection of cholesterol in human serum samples.
基金supported by the Education Bureau of the Fujian province (No. JAT160302) projectsthe Natural Science Foundation of Zhejiang province (No. LQ17C200002)the Talents’ Start-up Fund of Gannan Medical University (No. QD201825) projects。
文摘In this paper,we present a novel,reliable and sensitive electrochemical sensor for the determination of paracetamol based on hollow carbon Co3O4 nanosheets/reduced graphene oxide composite(Co3O4/r-GO).The Co3O4/r-GO was prepared via a rapid one-step microwave solvothermal process.Some series of techniques that included scanning electron microscopy,X-ray diffraction and Raman were carried out to characterize the morphology and structure of as-prepared materials.Most importantly,the developed electrochemical sensor exhibited a wide linear range of 0.05 to 900.0μM and a low detection limit of 14.0 nM(S/N=3)by using differential pulse voltammetry.Furthermore,the selectivity,repeatability,stability and practical applicability were further studied with satisfactory results.
