The thin films of Cu2O are deposited by electrodeposition technique onto indium tin oxide（ITO）-coated glass substrate at different potentials. The precursor is an aqueous solution which contains respectively 0.05 M ...The thin films of Cu2O are deposited by electrodeposition technique onto indium tin oxide（ITO）-coated glass substrate at different potentials. The precursor is an aqueous solution which contains respectively 0.05 M of CuSO4 and citric acid at kept temperature of 60℃ and the applied potential varies within the {-0：4 V,-0：7 V}SCE range. Based on the chronocoulometry（CC） process, the electrochemical, structural and optical parameters are determined. We measured the current as function of potential within the {-0：4 V,-0：7 V} range and the higher current is found to be within the {-0：7 V,-0：3 V} band. The grain sizes are of 12.12 nm and 35.47 nm according to（110） and（221） orientations respectively. The high textural coefficient of 0.943 is recorded for the potential -0：7 V.The transmittance of 72.25 %, within the visible band, is obtained for the as-grown layer at -0：4 V and the band gap is found to be 2.2 e V for the electrodeposition potential of -0：7 V.展开更多
The similar electrochemical oxidation behaviors of hydroxypivalaldehyde in ionic liquids （ILs） medium, C4MIMPF6, C4MIMBF4 and CsMIMPF6, are investigated using classic electrochemical methods, respectively. Only the ...The similar electrochemical oxidation behaviors of hydroxypivalaldehyde in ionic liquids （ILs） medium, C4MIMPF6, C4MIMBF4 and CsMIMPF6, are investigated using classic electrochemical methods, respectively. Only the product, hydroxypivalic acid is detected by high performance liquid chromatography （HPLC）. It can be conferred that the electrochemical oxidation of hydroxypivalaldehyde consists of two successive one-electron irreversible reactions at glass carbon （GC） electrode and the possible reaction mechanism in the ILs is proposed firstly. The diffusion coefficients of hydroxypivalaldehyde are obtained according to the electrochemical characteristics of hydroxypivalaldehyde in C4MIMPF6, C4MIMBF4 and CsMIMPF6.展开更多
The electrochemical behaviors of Eu3+ on Eastman AQ-29D/glassy carbon(GC) chemically modified electrode(CME) were studied. It was found that the reduction-oxidation process of Eu3+ is in a semi-infinite condition in 0...The electrochemical behaviors of Eu3+ on Eastman AQ-29D/glassy carbon(GC) chemically modified electrode(CME) were studied. It was found that the reduction-oxidation process of Eu3+ is in a semi-infinite condition in 0.1 mol/L NaCIO4 supporting electrolyte(pH 4.4). The calibration curve was linear over the range 1.0×10-7 to 1.0×105 mol/L of Eu3+.The charge transport apparent diffusion coefficient of Eu3+ in the polymer film was determined to be(3.2±1.1)×10-11cm2/s by chronocoulometry.展开更多
A silver electrode was anodized in lowly concentrated potassium chloride solution almost under the steady state to generate a deposit of silver chloride on the electrode, and the deposit was cathodically stripped by l...A silver electrode was anodized in lowly concentrated potassium chloride solution almost under the steady state to generate a deposit of silver chloride on the electrode, and the deposit was cathodically stripped by linear potential scan to evaluate the reduction charge. Then the oxidation charge was larger than the reduction one. Since the equality was valid for long term chronocoulometry at the double potential step, the inequality is not due to any irreversibility of electrode reactions, but can be attributed to the process of the cathodic potential scan. A reason for the inequality is the negative charge of the capacitance involved in the electrode reaction, which has been observed in simple, dissolved redox species like a ferrocenyl derivative. The negative capacitive currents are conspicuous for high concentrations of redox species on the electrode because they result from the orientation of the dipoles of the redox species coupled with counterion, of which direction is opposite to that of the solvent dipoles. If a silver chloride film was thin enough to be regarded as a monolayer, we found that half of the cathodic stripping charge should be lost by the negative capacitance.展开更多
Cholesterol is an important biochemical compound in human body, which forms many different hormones during metabolism and has a great effect on cardiovascular diseases. Study on cholesterol has been paid attention for...Cholesterol is an important biochemical compound in human body, which forms many different hormones during metabolism and has a great effect on cardiovascular diseases. Study on cholesterol has been paid attention for a long time. There are only two function groups: a double bond and a hydroxyl bond, in its molecular structure.展开更多
基金Project supported the PNR (Nos. 8/U311/R77, U311/R81)the "Agencethematique de rechercheen science ettechnologie" (ATRST)+2 种基金the National Administration of Scientific Researchthe CNEPRU of Oran University of Sciences and Technology (No. B00L02UN310220130011)the Scientific Research Projects Coordination (Nos. 2012-01-01-KAP05, 2012-01-01-KAP06) Yildiz Technical University
文摘The thin films of Cu2O are deposited by electrodeposition technique onto indium tin oxide（ITO）-coated glass substrate at different potentials. The precursor is an aqueous solution which contains respectively 0.05 M of CuSO4 and citric acid at kept temperature of 60℃ and the applied potential varies within the {-0：4 V,-0：7 V}SCE range. Based on the chronocoulometry（CC） process, the electrochemical, structural and optical parameters are determined. We measured the current as function of potential within the {-0：4 V,-0：7 V} range and the higher current is found to be within the {-0：7 V,-0：3 V} band. The grain sizes are of 12.12 nm and 35.47 nm according to（110） and（221） orientations respectively. The high textural coefficient of 0.943 is recorded for the potential -0：7 V.The transmittance of 72.25 %, within the visible band, is obtained for the as-grown layer at -0：4 V and the band gap is found to be 2.2 e V for the electrodeposition potential of -0：7 V.
文摘The similar electrochemical oxidation behaviors of hydroxypivalaldehyde in ionic liquids （ILs） medium, C4MIMPF6, C4MIMBF4 and CsMIMPF6, are investigated using classic electrochemical methods, respectively. Only the product, hydroxypivalic acid is detected by high performance liquid chromatography （HPLC）. It can be conferred that the electrochemical oxidation of hydroxypivalaldehyde consists of two successive one-electron irreversible reactions at glass carbon （GC） electrode and the possible reaction mechanism in the ILs is proposed firstly. The diffusion coefficients of hydroxypivalaldehyde are obtained according to the electrochemical characteristics of hydroxypivalaldehyde in C4MIMPF6, C4MIMBF4 and CsMIMPF6.
文摘The electrochemical behaviors of Eu3+ on Eastman AQ-29D/glassy carbon(GC) chemically modified electrode(CME) were studied. It was found that the reduction-oxidation process of Eu3+ is in a semi-infinite condition in 0.1 mol/L NaCIO4 supporting electrolyte(pH 4.4). The calibration curve was linear over the range 1.0×10-7 to 1.0×105 mol/L of Eu3+.The charge transport apparent diffusion coefficient of Eu3+ in the polymer film was determined to be(3.2±1.1)×10-11cm2/s by chronocoulometry.
文摘A silver electrode was anodized in lowly concentrated potassium chloride solution almost under the steady state to generate a deposit of silver chloride on the electrode, and the deposit was cathodically stripped by linear potential scan to evaluate the reduction charge. Then the oxidation charge was larger than the reduction one. Since the equality was valid for long term chronocoulometry at the double potential step, the inequality is not due to any irreversibility of electrode reactions, but can be attributed to the process of the cathodic potential scan. A reason for the inequality is the negative charge of the capacitance involved in the electrode reaction, which has been observed in simple, dissolved redox species like a ferrocenyl derivative. The negative capacitive currents are conspicuous for high concentrations of redox species on the electrode because they result from the orientation of the dipoles of the redox species coupled with counterion, of which direction is opposite to that of the solvent dipoles. If a silver chloride film was thin enough to be regarded as a monolayer, we found that half of the cathodic stripping charge should be lost by the negative capacitance.
文摘Cholesterol is an important biochemical compound in human body, which forms many different hormones during metabolism and has a great effect on cardiovascular diseases. Study on cholesterol has been paid attention for a long time. There are only two function groups: a double bond and a hydroxyl bond, in its molecular structure.
