Manganese ferrite(MnFe_(2)O_(4))has the advantages of simple preparation,high resistivity,and high crystal symmetry.Herein,we have developed an electrochemical sensor utilizing graphene and MnFe_(2)O_(4) nanocomposite...Manganese ferrite(MnFe_(2)O_(4))has the advantages of simple preparation,high resistivity,and high crystal symmetry.Herein,we have developed an electrochemical sensor utilizing graphene and MnFe_(2)O_(4) nanocomposites modified glassy carbon electrode(GCE),which is very efficient and sensitive to detect bisphenol A(BPA).MnFe_(2)O_(4)/graphene(GR)was synthesized by immobilizing the MnFe_(2)O_(4) microspheres on the graphene nanosheets via a simple one-pot solvothermal method.The morphology and structure of the MnFe_(2)O_(4)/GR nanocomposite have been characterized through scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).In addition,electrochemical properties of the modified materials are comparably explored by means of cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS)and differential pulse voltammetry(DPV).Under the optimal conditions,the proposed electrochemical sensor for the detection of BPA has a linear range of 0.8-400μmol/L and a detection limit of 0.0235μmol/L(S/N=3)with high sensitivity,good selectivity and high stability.In addition,the proposed sensor was used to measure the content of BPA in real water samples with a recovery rate of 97.94%-104.56%.At present,the synthesis of MnFe_(2)O_(4)/GR provides more opportunities for the electrochemical detection of BPA in practical applications.展开更多
Reasonably constructing an atomic interface is pronouncedly essential for surface-related gas-sensing reaction.Herein,we present an ingen-ious feedback-regulation system by changing the interactional mode between sing...Reasonably constructing an atomic interface is pronouncedly essential for surface-related gas-sensing reaction.Herein,we present an ingen-ious feedback-regulation system by changing the interactional mode between single Pt atoms and adjacent S species for high-efficiency SO_(2)sensing.We found that the single Pt sites on the MoS_(2)surface can induce easier volatiliza-tion of adjacent S species to activate the whole inert S plane.Reversely,the activated S species can provide a feedback role in tailoring the antibonding-orbital electronic occupancy state of Pt atoms,thus creating a combined system involving S vacancy-assisted single Pt sites(Pt-Vs)to synergistically improve the adsorption ability of SO_(2)gas molecules.Further-more,in situ Raman,ex situ X-ray photoelectron spectroscopy testing and density functional theory analysis demonstrate the intact feedback-regulation system can expand the electron transfer path from single Pt sites to whole Pt-MoS_(2)supports in SO_(2)gas atmosphere.Equipped with wireless-sensing modules,the final Pt1-MoS_(2)-def sensors array can further realize real-time monitoring of SO_(2)levels and cloud-data storage for plant growth.Such a fundamental understanding of the intrinsic link between atomic interface and sensing mechanism is thus expected to broaden the rational design of highly effective gas sensors.展开更多
Copper-based nanomaterials have been widely used in catalysis,electrodes,and other applications due to their unique electron-transfer properties.In this work,an efficient electrochemical sensor based on an electrode m...Copper-based nanomaterials have been widely used in catalysis,electrodes,and other applications due to their unique electron-transfer properties.In this work,an efficient electrochemical sensor based on an electrode modified with one-dimensional Cu(OH)_(2)/carboxymethyl cellulose(CMC)composite nanofibers was fabricated and investigated for the detection of aspirin.Scanning electron microscopy was employed to examine the morphological characteristics of these composite nanofibers.Cyclic voltammetry and electrochemical impedance spectroscopy were used to assess the electrochemical performance of a Cu(OH)_(2)/CMC composite nanofiber-modified electrode.The findings indicate that the modified electrode has a very high sensitivity to aspirin.The observed enhanced performance could be a result of the high surface-to-volume ratio of the composite nanofibers and their superior electron-transport characteristics,which may hasten electron transfer between aspirin and the surfaces of the modified electrode.This detection technique also demonstrated strong selectivity for aspirin.These findings imply that the technique can be applied as a highly effective and selective approach to aspirin measurement in biological science.展开更多
ZnO nanocrystals were prepared by a direct current electrochemical deposition process under 3.0V working voltage and 30A/m^2 current density using zinc sulfate as raw materials.The nanocrystals were characterized by X...ZnO nanocrystals were prepared by a direct current electrochemical deposition process under 3.0V working voltage and 30A/m^2 current density using zinc sulfate as raw materials.The nanocrystals were characterized by X-ray diffraction (XRD)and transmission electron microscopy(TEM).The results indicated that the nanocrystals are hexagonal wurtzite ZnO with particle size range of 25nm～40nm without any treating.Gas sensing properties of the sensors were tested by mixing a gas in air at static state;the tested results showed that the sensors based on nanocrystalline ZnO had satisfied gas sensing properties to H_2S gas at rather low temperature.展开更多
A rod-like NiCo2O4 modified glassy carbon electrode was fabricated and used for non-enzymatic glucose sensing. The NiCo2O4 was prepared by a facile hydrothermal reaction and subsequently treated in a commercial microw...A rod-like NiCo2O4 modified glassy carbon electrode was fabricated and used for non-enzymatic glucose sensing. The NiCo2O4 was prepared by a facile hydrothermal reaction and subsequently treated in a commercial microwave oven to eliminate the residual water introduced during the hydrothermal procedure. Structural analysis showed that there was no significant structural alteration before and after microwave treatment. The elimination of water residuals was confirmed by the stoichiometric ratio change by using element analysis. The microwave treated NiCo2O4 (M-NiCo2O4) showed excellent performance as a glucose sensor (sensitivity 431.29 μA·mmol/L-1·cm-2). The sensing performance decreases dramatically by soaking the M-NiCo2O4 in water. This result indicates that the introduction of residual water during hydrothermal process strongly affects the electrochemical performance and microwave pre-treatment is crucial for better sensory performance.展开更多
基金Project(2108085ME184)supported by the Natural Science Foundation of Anhui Province,ChinaProject(2022AH010019)supported by the Innovation Team Project of Anhui Provincial Department of Education,China+1 种基金Project(GXXT-2021-057)supported by the Collaborative Innovation Project of Anhui Provincial Department of Education,ChinaProject(2020QDZ36)supported by the Doctoral Scientific Research Startup Foundation of Anhui Jianzhu University,China。
文摘Manganese ferrite(MnFe_(2)O_(4))has the advantages of simple preparation,high resistivity,and high crystal symmetry.Herein,we have developed an electrochemical sensor utilizing graphene and MnFe_(2)O_(4) nanocomposites modified glassy carbon electrode(GCE),which is very efficient and sensitive to detect bisphenol A(BPA).MnFe_(2)O_(4)/graphene(GR)was synthesized by immobilizing the MnFe_(2)O_(4) microspheres on the graphene nanosheets via a simple one-pot solvothermal method.The morphology and structure of the MnFe_(2)O_(4)/GR nanocomposite have been characterized through scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).In addition,electrochemical properties of the modified materials are comparably explored by means of cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS)and differential pulse voltammetry(DPV).Under the optimal conditions,the proposed electrochemical sensor for the detection of BPA has a linear range of 0.8-400μmol/L and a detection limit of 0.0235μmol/L(S/N=3)with high sensitivity,good selectivity and high stability.In addition,the proposed sensor was used to measure the content of BPA in real water samples with a recovery rate of 97.94%-104.56%.At present,the synthesis of MnFe_(2)O_(4)/GR provides more opportunities for the electrochemical detection of BPA in practical applications.
基金This work was supported by the National Natural Science Foundation of China(62271299)Shanghai Sailing Program(22YF1413400).Shanghai Engineering Research Center for We thank the Integrated Circuits and Advanced Display Materials.
文摘Reasonably constructing an atomic interface is pronouncedly essential for surface-related gas-sensing reaction.Herein,we present an ingen-ious feedback-regulation system by changing the interactional mode between single Pt atoms and adjacent S species for high-efficiency SO_(2)sensing.We found that the single Pt sites on the MoS_(2)surface can induce easier volatiliza-tion of adjacent S species to activate the whole inert S plane.Reversely,the activated S species can provide a feedback role in tailoring the antibonding-orbital electronic occupancy state of Pt atoms,thus creating a combined system involving S vacancy-assisted single Pt sites(Pt-Vs)to synergistically improve the adsorption ability of SO_(2)gas molecules.Further-more,in situ Raman,ex situ X-ray photoelectron spectroscopy testing and density functional theory analysis demonstrate the intact feedback-regulation system can expand the electron transfer path from single Pt sites to whole Pt-MoS_(2)supports in SO_(2)gas atmosphere.Equipped with wireless-sensing modules,the final Pt1-MoS_(2)-def sensors array can further realize real-time monitoring of SO_(2)levels and cloud-data storage for plant growth.Such a fundamental understanding of the intrinsic link between atomic interface and sensing mechanism is thus expected to broaden the rational design of highly effective gas sensors.
基金The authors wish to acknowledge financial support from the Science and Technology Projects in Jilin Province Department of Education(Grant No.JJKH20220239KJ).
文摘Copper-based nanomaterials have been widely used in catalysis,electrodes,and other applications due to their unique electron-transfer properties.In this work,an efficient electrochemical sensor based on an electrode modified with one-dimensional Cu(OH)_(2)/carboxymethyl cellulose(CMC)composite nanofibers was fabricated and investigated for the detection of aspirin.Scanning electron microscopy was employed to examine the morphological characteristics of these composite nanofibers.Cyclic voltammetry and electrochemical impedance spectroscopy were used to assess the electrochemical performance of a Cu(OH)_(2)/CMC composite nanofiber-modified electrode.The findings indicate that the modified electrode has a very high sensitivity to aspirin.The observed enhanced performance could be a result of the high surface-to-volume ratio of the composite nanofibers and their superior electron-transport characteristics,which may hasten electron transfer between aspirin and the surfaces of the modified electrode.This detection technique also demonstrated strong selectivity for aspirin.These findings imply that the technique can be applied as a highly effective and selective approach to aspirin measurement in biological science.
文摘ZnO nanocrystals were prepared by a direct current electrochemical deposition process under 3.0V working voltage and 30A/m^2 current density using zinc sulfate as raw materials.The nanocrystals were characterized by X-ray diffraction (XRD)and transmission electron microscopy(TEM).The results indicated that the nanocrystals are hexagonal wurtzite ZnO with particle size range of 25nm～40nm without any treating.Gas sensing properties of the sensors were tested by mixing a gas in air at static state;the tested results showed that the sensors based on nanocrystalline ZnO had satisfied gas sensing properties to H_2S gas at rather low temperature.
基金supported by the Shandong Provincial Natural Science Foundation,China(No.ZR2017QB015)the National Natural Science Foundation of China(No.21773309)China University of Petroleum Student’s Platform for Innovation and Entrepreneurship Training Program(No.20161449)
文摘A rod-like NiCo2O4 modified glassy carbon electrode was fabricated and used for non-enzymatic glucose sensing. The NiCo2O4 was prepared by a facile hydrothermal reaction and subsequently treated in a commercial microwave oven to eliminate the residual water introduced during the hydrothermal procedure. Structural analysis showed that there was no significant structural alteration before and after microwave treatment. The elimination of water residuals was confirmed by the stoichiometric ratio change by using element analysis. The microwave treated NiCo2O4 (M-NiCo2O4) showed excellent performance as a glucose sensor (sensitivity 431.29 μA·mmol/L-1·cm-2). The sensing performance decreases dramatically by soaking the M-NiCo2O4 in water. This result indicates that the introduction of residual water during hydrothermal process strongly affects the electrochemical performance and microwave pre-treatment is crucial for better sensory performance.
