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
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
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
通过电化学剥离协同制备了3D Ni(OH)_(2)/石墨烯复合电极薄膜材料,高品质石墨烯均匀地生长在三维Ni(OH)_(2)表面,电化学性能测试表明,在2 m A/cm^(2)电流密度条件下,该电极薄膜具有优异的比电容(266 m F/cm^(2)),经过1万次的连续充放电...通过电化学剥离协同制备了3D Ni(OH)_(2)/石墨烯复合电极薄膜材料,高品质石墨烯均匀地生长在三维Ni(OH)_(2)表面,电化学性能测试表明,在2 m A/cm^(2)电流密度条件下,该电极薄膜具有优异的比电容(266 m F/cm^(2)),经过1万次的连续充放电循环测试仍然保留94.1%的容量性能。该方法为大规模生产新型高性能电极薄膜材料提供了一个简单的制备策略。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.
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.
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.
文摘通过电化学剥离协同制备了3D Ni(OH)_(2)/石墨烯复合电极薄膜材料,高品质石墨烯均匀地生长在三维Ni(OH)_(2)表面,电化学性能测试表明,在2 m A/cm^(2)电流密度条件下,该电极薄膜具有优异的比电容(266 m F/cm^(2)),经过1万次的连续充放电循环测试仍然保留94.1%的容量性能。该方法为大规模生产新型高性能电极薄膜材料提供了一个简单的制备策略。
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.
