A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The ...A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The electrochemical behavior of captopril (CAP) at the surface of the modified electrode was investigated using electroanalytical methods. The modified electrode showed excellent electrocatalytic activity for the oxidation of CAP in aqueous solutions at physiological pH values. Cyclic voltammetric curves showed that the oxidation of CAP at the surface of the modified electrode reduced its overpotential by more than 290 mV. The modified electrode was used for detecting captopril using cyclic voltammetry and square wave voltammetry techniques. A calibration curve in the range of 0.03 to 2400 μmol/L was obtained that had a detection limit of 0.0096 μmol/L (3?) under the optimized conditions. The modified electrode was successfully used for the determination of captopril in pharmaceutical and biological samples.展开更多
This paper reports the improvement of electrical,ferroelectric and endurance of Hf_(0.5)Zr_(0.5)O_(2)(HZO)thinfilm capacitors by implementing W electrode.The W/HZO/W capacitor shows excellent pristine 2 P_(r)values of...This paper reports the improvement of electrical,ferroelectric and endurance of Hf_(0.5)Zr_(0.5)O_(2)(HZO)thinfilm capacitors by implementing W electrode.The W/HZO/W capacitor shows excellent pristine 2 P_(r)values of 45.1 gC/cm^(2)at±6 V,which are much higher than those of TiN/HZO/W(34.4μC/cm^(2))and W/HZO/TiN(26.9μC/cm^(2))capacitors.Notably,the maximum initial 2 P_(r)value of W/HZO/W capacitor can reach as high as 57.9μC/cm^(2)at±7.5 V.These strong ferroelectric polarization effects are ascribed to the W electrode with a fairly low thermal expansion coefficient which provides a larger in-plane tensile strain compared with TiN electrode,allowing for enhancement of o-phase formation.Moreover,the W/HZO/W capacitor also exhibits higher endurance,smaller wake-up effect(10.1%)and superior fatigue properties up to 1.5×10^(10)cycles compared to the TiN/HZO/W and W/HZO/TiN capacitors.Such improvements of W/HZO/W capacitor are mainly due to the decreased leakage current by more than an order of magnitude compared to the W/HZO/TiN capacitor.These results demonstrate that capping electrode material plays an important role in the enhancement of o-phase formation,reduces oxygen vacancies,mitigates wake-up effect and improves reliability.展开更多
A photoelectrochemical process in the degradation of an azodye (Acid Orange II) on a Pt/TiO 2 film electrode was investigated. By using the glass device and the voltage stabilized source of direct current, decoloriza...A photoelectrochemical process in the degradation of an azodye (Acid Orange II) on a Pt/TiO 2 film electrode was investigated. By using the glass device and the voltage stabilized source of direct current, decolorization ratios higher than 78% were observed during a period of 5h. Comparing this value with the sum of the decolorization ratios obtained by a sole application of electrochemical(lower than 3%) and photochemical(about 23%) procedures, a significant synergic effect between both processes was observed. The effects of adscititious voltage and pH value on the decolorization ratios were obvious while the effect of the amount of aeration was minor.展开更多
Morphology-controllable Cu2SnS3 thin films on solvothermal process and used in dye-sensitized solar cells as Mo-glass were prepared via a facile in situ one-step counter electrodes. The effects of different solvents ...Morphology-controllable Cu2SnS3 thin films on solvothermal process and used in dye-sensitized solar cells as Mo-glass were prepared via a facile in situ one-step counter electrodes. The effects of different solvents on the morphology of films were investigated. DSC based on the porous net-like Cu2SnS3 thin film as counter electrodes showed a power conversion efficiency of 2.30%, which was improved to 3.35% after annealing.展开更多
Nano sized powders of TiO2 （titanium dioxide） and Nb2O5 （Niobium （V） oxide） were used to fabricate TiO2/Nb2O5 composites thin films by EPD （electrophoretic deposition） technique. The metal oxide powders, toget...Nano sized powders of TiO2 （titanium dioxide） and Nb2O5 （Niobium （V） oxide） were used to fabricate TiO2/Nb2O5 composites thin films by EPD （electrophoretic deposition） technique. The metal oxide powders, together with magnesium nitrate hexahydrate pellets, were suspended in propan-2-ol inside an EPD cell. The electrodes, placed 1.2 cm apart, were partially immersed in the suspension and a DC potential applied across them. Key EPD process parameters, which include applied DC electric field, deposition time and solid concentration in suspension, were optimized through visual inspection and from UV-Vis-NIR spectrophotometer spectra. The highest （55%） transmittance was obtained for films with deposition time of 90 s, powder concentration of 0.01 g/40 mL, and 35 V DC （direct current） voltage. XRD micrographs confirmed that TiO2 and Nb2O5 particles were presented in the composite film. SEM （scanning electron microscope） micrographs of the composite electrode thin films showed that porous films of high quality with well controlled morphology were deposited by using the EPD technique.展开更多
Mn:ZnSe/ZnS/L-Cys core-shell quantum dots(QDs)sensitized La-doped nano-TiO2 thin film(QDSTF)was prepared.X-ray photoelectron spectroscopy(XPS),nanosecond transient photovoltaic(TPV),and steady state surface photovolta...Mn:ZnSe/ZnS/L-Cys core-shell quantum dots(QDs)sensitized La-doped nano-TiO2 thin film(QDSTF)was prepared.X-ray photoelectron spectroscopy(XPS),nanosecond transient photovoltaic(TPV),and steady state surface photovoltaic(SPV)technologies were used for probing the photoelectron behaviors in the Mn-doped QDSTF.The results revealed that the Mn-doped QDSTF had a p-type TPV characteristic.The bottom of the conduction band of the QDs as a sensitizer was just 0.86 eV above that of the La-doped nano-TiO2 thin film,while the acceptor level of the doped Mn2+ions was located at about 0.39 eV below and near the bottom of the conduction band of the QDs.The intensity of the SPV response of the Mn-doped QDSTF at a specific wavelength was ~2.1 times higher than that of the undoped QDSTF.The region of the SPV response of the Mn-doped QDSTF was extended by 191 nm to almost the whole visible region as compared with the undoped QDSTF one.And the region of the TPV response of the Mn-doped QDSTF was also obviously wider than that of the undoped QDSTF.These PV characteristics of the Mn-doped QDSTF may be due to the prolonged lifetime and extended diffusion length of photogenerated free charge carriers injected into the sensitized La-doped nano-TiO2 thin film.展开更多
Surgical electrodes are frequently associated with disadvantages such as high surface adhesion and severe thermal damage to adjacent normal tissues,which threaten operation quality and patient safety.In this study,by ...Surgical electrodes are frequently associated with disadvantages such as high surface adhesion and severe thermal damage to adjacent normal tissues,which threaten operation quality and patient safety.In this study,by mimicking the micromorphology and bio-anti-adhesion of shark skin,we proposed a strategy that utilized nanoscale aluminium oxide(Al_(2)O_(3))films deposited on bioinspired shark skin(BSS)microstructures to design a composite surface(Al_(2)O_(3)@BSS)and integrated it into both flat sides of the surgical electrodes.Micro/nano-manufacturing of the Al_(2)O_(3)@BSS surface was sequentially accomplished using nanosecond laser texturing,atomic layer deposition,and low-temperature annealing,endowing it with excellent blood-repellent properties.Visualisation experiments revealed that the tensile stress gradient of the blood coagulum with increasing thickness under a thermal field prompted it to separate from the Al_(2)O_(3)@BSS surface,resulting in anti-adhesion.Furthermore,it was observed for the first time that Al_(2)O_(3) films could transiently excite discharge along a dielectric surface(DADS)to ablate tissues while suppressing Joule heat,thereby minimising thermal damage.A combination of ex vivo tissue and living mouse experiments demonstrated that the Al_(2)O_(3)@BSS electrodes exhibited optimal comprehensive performance in terms of anti-adhesion,damage minimisation,and drag reduction.In addition,the Al_(2)O_(3)@BSS electrodes possessed remarkable antibacterial efficacy against E.coli and S.aureus.The proposed strategy can meet the extreme application requirements of surgical electrodes to improve operation quality and offer valuable insights for future studies.展开更多
High-scalability HfO_(2)-based ferroelectric thin films are promising for application in fast,energy-efficient,and high-density non-volatile memories.This ferroelectricity is believed to originate from the metastable ...High-scalability HfO_(2)-based ferroelectric thin films are promising for application in fast,energy-efficient,and high-density non-volatile memories.This ferroelectricity is believed to originate from the metastable orthorhombic phase,which is difficult to obtain.Post-metallization annealing with a top electrode capping layer is a useful method for stabilizing the ferroelectric orthorhombic phase.However,direct physical evidence of the top electrode role is lacking.In this study,we visualized the dynamic process of the phase transition in Hf_(0.5)Zr_(0.5)O_(2)(HZO)thin films with TiN and Pt top electrodes during the heating and cooling processes through in-situ scanning transmission electron microscopy(STEM).The TiN top electrode stabilized the orthorhombic phase,whereas the Pt top electrode induced a phase transition to the monoclinic phase.Subsequently,we elucidated the phase transition mechanism in HZO thin films using the kinetic effect and revealed that it was related to the concentration of oxygen vacancies induced by the top electrode.This study provides valuable insights into the stabilization of the orthorhombic phase in HfO_(2)-based ferroelectric thin films and contributes to the elucidation of the phase transition mechanism of HfO_(2)-based ferroelectric thin films.展开更多
This study investigates the impact of oxide bottom electrode(BE)material and orientation on the resistive switching(RS)characteristics of Al/ZrO_(2)-based ReRAM devices.Devices with different oxide BEs,including(400)-...This study investigates the impact of oxide bottom electrode(BE)material and orientation on the resistive switching(RS)characteristics of Al/ZrO_(2)-based ReRAM devices.Devices with different oxide BEs,including(400)-and(222)-oriented ITO BEs deposited under pure argon and argon–oxygen(20%O_(2))sputtering atmospheres,as well as SrRuO_(3)(SRO),show distinct RS behaviors.The Al/ZrO_(2)/(400)-ITO and Al/ZrO_(2)/SRO devices demonstrate stable bipolar RS performance,with(400)-ITO enabling an abrupt reset process,a wider memory window(>10^(4)),and superior stability,while SRO devices exhibit gradual reset transitions with lower power consumption.Furthermore,the crystallographic orientation control applied to ITO BE significantly affects the V_(O) dynamics and RS performance,with(222)-ITO devices exhibiting irreversible RS behavior.It is irrefutable that BE material and its orientation can strongly influence RS performance by modulating the V_(O) dynamics,electric field distribution,and conductive filament behavior.These findings underscore the importance of BE properties in optimizing ReRAM performance and provide valuable guidance for the development of high-efficiency memory devices.展开更多
The photocurrent created by the TiO 2 nanoporous film electrode modified by octadecanethiol(18SH) self-assembled monolayer(SAM) was found to be 1 95 times greater than that without modification as shown by cyclic volt...The photocurrent created by the TiO 2 nanoporous film electrode modified by octadecanethiol(18SH) self-assembled monolayer(SAM) was found to be 1 95 times greater than that without modification as shown by cyclic voltammetry(CV). Meanwhile the maximum adsorbed peak has extended to the infrared range for about 20 nm. The formation of SAM was also assured with CV and small amplitude isosceles triangle potential methods, where the sensitization of SAM on the oxidation of CH 3OH on the TiO 2 nanoporous film electrode could be observed clearly. The results elucidated that the increased photocurrent by modification of octadecanethiol could not be simply attributed to the oxidation of octadecanethiol or ethanol. The results also implied that the application of SAM would be practicable in the sensitization of TiO 2 nanoporous film electrode in solar cell area.展开更多
文摘A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The electrochemical behavior of captopril (CAP) at the surface of the modified electrode was investigated using electroanalytical methods. The modified electrode showed excellent electrocatalytic activity for the oxidation of CAP in aqueous solutions at physiological pH values. Cyclic voltammetric curves showed that the oxidation of CAP at the surface of the modified electrode reduced its overpotential by more than 290 mV. The modified electrode was used for detecting captopril using cyclic voltammetry and square wave voltammetry techniques. A calibration curve in the range of 0.03 to 2400 μmol/L was obtained that had a detection limit of 0.0096 μmol/L (3?) under the optimized conditions. The modified electrode was successfully used for the determination of captopril in pharmaceutical and biological samples.
基金financially supported by the National Natural Science Foundation of China(No.51872099)the Hong Kong Research Grant Council(No.15300619)+2 种基金the Science and Technology Program of Guangzhou(No.201905-0001)the Guangdong Science and Technology Project-International Cooperation(No.2021A0505030064)financial support by the Hong Kong Scholars Program(No.XJ2019006)。
文摘This paper reports the improvement of electrical,ferroelectric and endurance of Hf_(0.5)Zr_(0.5)O_(2)(HZO)thinfilm capacitors by implementing W electrode.The W/HZO/W capacitor shows excellent pristine 2 P_(r)values of 45.1 gC/cm^(2)at±6 V,which are much higher than those of TiN/HZO/W(34.4μC/cm^(2))and W/HZO/TiN(26.9μC/cm^(2))capacitors.Notably,the maximum initial 2 P_(r)value of W/HZO/W capacitor can reach as high as 57.9μC/cm^(2)at±7.5 V.These strong ferroelectric polarization effects are ascribed to the W electrode with a fairly low thermal expansion coefficient which provides a larger in-plane tensile strain compared with TiN electrode,allowing for enhancement of o-phase formation.Moreover,the W/HZO/W capacitor also exhibits higher endurance,smaller wake-up effect(10.1%)and superior fatigue properties up to 1.5×10^(10)cycles compared to the TiN/HZO/W and W/HZO/TiN capacitors.Such improvements of W/HZO/W capacitor are mainly due to the decreased leakage current by more than an order of magnitude compared to the W/HZO/TiN capacitor.These results demonstrate that capping electrode material plays an important role in the enhancement of o-phase formation,reduces oxygen vacancies,mitigates wake-up effect and improves reliability.
文摘A photoelectrochemical process in the degradation of an azodye (Acid Orange II) on a Pt/TiO 2 film electrode was investigated. By using the glass device and the voltage stabilized source of direct current, decolorization ratios higher than 78% were observed during a period of 5h. Comparing this value with the sum of the decolorization ratios obtained by a sole application of electrochemical(lower than 3%) and photochemical(about 23%) procedures, a significant synergic effect between both processes was observed. The effects of adscititious voltage and pH value on the decolorization ratios were obvious while the effect of the amount of aeration was minor.
基金financially supported by the National Natural Science Foundation of China (No. 21203226)
文摘Morphology-controllable Cu2SnS3 thin films on solvothermal process and used in dye-sensitized solar cells as Mo-glass were prepared via a facile in situ one-step counter electrodes. The effects of different solvents on the morphology of films were investigated. DSC based on the porous net-like Cu2SnS3 thin film as counter electrodes showed a power conversion efficiency of 2.30%, which was improved to 3.35% after annealing.
文摘Nano sized powders of TiO2 （titanium dioxide） and Nb2O5 （Niobium （V） oxide） were used to fabricate TiO2/Nb2O5 composites thin films by EPD （electrophoretic deposition） technique. The metal oxide powders, together with magnesium nitrate hexahydrate pellets, were suspended in propan-2-ol inside an EPD cell. The electrodes, placed 1.2 cm apart, were partially immersed in the suspension and a DC potential applied across them. Key EPD process parameters, which include applied DC electric field, deposition time and solid concentration in suspension, were optimized through visual inspection and from UV-Vis-NIR spectrophotometer spectra. The highest （55%） transmittance was obtained for films with deposition time of 90 s, powder concentration of 0.01 g/40 mL, and 35 V DC （direct current） voltage. XRD micrographs confirmed that TiO2 and Nb2O5 particles were presented in the composite film. SEM （scanning electron microscope） micrographs of the composite electrode thin films showed that porous films of high quality with well controlled morphology were deposited by using the EPD technique.
基金Project supported by the Natural Science Foundation of Hebei Province,China(Grant No.E2017203029)。
文摘Mn:ZnSe/ZnS/L-Cys core-shell quantum dots(QDs)sensitized La-doped nano-TiO2 thin film(QDSTF)was prepared.X-ray photoelectron spectroscopy(XPS),nanosecond transient photovoltaic(TPV),and steady state surface photovoltaic(SPV)technologies were used for probing the photoelectron behaviors in the Mn-doped QDSTF.The results revealed that the Mn-doped QDSTF had a p-type TPV characteristic.The bottom of the conduction band of the QDs as a sensitizer was just 0.86 eV above that of the La-doped nano-TiO2 thin film,while the acceptor level of the doped Mn2+ions was located at about 0.39 eV below and near the bottom of the conduction band of the QDs.The intensity of the SPV response of the Mn-doped QDSTF at a specific wavelength was ~2.1 times higher than that of the undoped QDSTF.The region of the SPV response of the Mn-doped QDSTF was extended by 191 nm to almost the whole visible region as compared with the undoped QDSTF one.And the region of the TPV response of the Mn-doped QDSTF was also obviously wider than that of the undoped QDSTF.These PV characteristics of the Mn-doped QDSTF may be due to the prolonged lifetime and extended diffusion length of photogenerated free charge carriers injected into the sensitized La-doped nano-TiO2 thin film.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52275425,52405473,and 52405472)the Natural Science Foundation of Guangdong Province(Grant No.2024A1515010993)。
文摘Surgical electrodes are frequently associated with disadvantages such as high surface adhesion and severe thermal damage to adjacent normal tissues,which threaten operation quality and patient safety.In this study,by mimicking the micromorphology and bio-anti-adhesion of shark skin,we proposed a strategy that utilized nanoscale aluminium oxide(Al_(2)O_(3))films deposited on bioinspired shark skin(BSS)microstructures to design a composite surface(Al_(2)O_(3)@BSS)and integrated it into both flat sides of the surgical electrodes.Micro/nano-manufacturing of the Al_(2)O_(3)@BSS surface was sequentially accomplished using nanosecond laser texturing,atomic layer deposition,and low-temperature annealing,endowing it with excellent blood-repellent properties.Visualisation experiments revealed that the tensile stress gradient of the blood coagulum with increasing thickness under a thermal field prompted it to separate from the Al_(2)O_(3)@BSS surface,resulting in anti-adhesion.Furthermore,it was observed for the first time that Al_(2)O_(3) films could transiently excite discharge along a dielectric surface(DADS)to ablate tissues while suppressing Joule heat,thereby minimising thermal damage.A combination of ex vivo tissue and living mouse experiments demonstrated that the Al_(2)O_(3)@BSS electrodes exhibited optimal comprehensive performance in terms of anti-adhesion,damage minimisation,and drag reduction.In addition,the Al_(2)O_(3)@BSS electrodes possessed remarkable antibacterial efficacy against E.coli and S.aureus.The proposed strategy can meet the extreme application requirements of surgical electrodes to improve operation quality and offer valuable insights for future studies.
基金supported by the Scientific Research Innovation Capability Support Project for Young Faculty(Grant No.ZYGXQNJSKYCXNLZCXM-M22)the National Natural Science Foundation of China(Grant Nos.52122205,51901166,12302429,12474092 and 52250308)+4 种基金the National Key Research and Development Program of China(Grant No.2024YFA1208603)the Natural Science Basic Research Program of Shaanxi(Program No.2024JC-YBQN-0583)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110116)the Fundamental Research Funds for the Central Universitiesthe Innovation Fund of Xidian University.
文摘High-scalability HfO_(2)-based ferroelectric thin films are promising for application in fast,energy-efficient,and high-density non-volatile memories.This ferroelectricity is believed to originate from the metastable orthorhombic phase,which is difficult to obtain.Post-metallization annealing with a top electrode capping layer is a useful method for stabilizing the ferroelectric orthorhombic phase.However,direct physical evidence of the top electrode role is lacking.In this study,we visualized the dynamic process of the phase transition in Hf_(0.5)Zr_(0.5)O_(2)(HZO)thin films with TiN and Pt top electrodes during the heating and cooling processes through in-situ scanning transmission electron microscopy(STEM).The TiN top electrode stabilized the orthorhombic phase,whereas the Pt top electrode induced a phase transition to the monoclinic phase.Subsequently,we elucidated the phase transition mechanism in HZO thin films using the kinetic effect and revealed that it was related to the concentration of oxygen vacancies induced by the top electrode.This study provides valuable insights into the stabilization of the orthorhombic phase in HfO_(2)-based ferroelectric thin films and contributes to the elucidation of the phase transition mechanism of HfO_(2)-based ferroelectric thin films.
基金supported in part by the National Natural Science Foundation of China(Grant Nos.51602160 and 61605086)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20150842)the Talent Project of Nanjing University of Posts and Telecommunications(NUPTSF)(Grant No.NY222127)。
文摘This study investigates the impact of oxide bottom electrode(BE)material and orientation on the resistive switching(RS)characteristics of Al/ZrO_(2)-based ReRAM devices.Devices with different oxide BEs,including(400)-and(222)-oriented ITO BEs deposited under pure argon and argon–oxygen(20%O_(2))sputtering atmospheres,as well as SrRuO_(3)(SRO),show distinct RS behaviors.The Al/ZrO_(2)/(400)-ITO and Al/ZrO_(2)/SRO devices demonstrate stable bipolar RS performance,with(400)-ITO enabling an abrupt reset process,a wider memory window(>10^(4)),and superior stability,while SRO devices exhibit gradual reset transitions with lower power consumption.Furthermore,the crystallographic orientation control applied to ITO BE significantly affects the V_(O) dynamics and RS performance,with(222)-ITO devices exhibiting irreversible RS behavior.It is irrefutable that BE material and its orientation can strongly influence RS performance by modulating the V_(O) dynamics,electric field distribution,and conductive filament behavior.These findings underscore the importance of BE properties in optimizing ReRAM performance and provide valuable guidance for the development of high-efficiency memory devices.
文摘The photocurrent created by the TiO 2 nanoporous film electrode modified by octadecanethiol(18SH) self-assembled monolayer(SAM) was found to be 1 95 times greater than that without modification as shown by cyclic voltammetry(CV). Meanwhile the maximum adsorbed peak has extended to the infrared range for about 20 nm. The formation of SAM was also assured with CV and small amplitude isosceles triangle potential methods, where the sensitization of SAM on the oxidation of CH 3OH on the TiO 2 nanoporous film electrode could be observed clearly. The results elucidated that the increased photocurrent by modification of octadecanethiol could not be simply attributed to the oxidation of octadecanethiol or ethanol. The results also implied that the application of SAM would be practicable in the sensitization of TiO 2 nanoporous film electrode in solar cell area.
