Papers by Keyword: Electrocatalysis

Abstract: This paper studied the preparation method of the multi-walled carbon ITO nanotubes electrode, which was prepared by ITO electrode self-assembled after adsorbing n-Dodecanethiol.The multi-walled carbon ITO nanotubes electrode was prepared by self-assembled after adsorbed n-Dodecanethiol.The electrode was characterized with DA as the representative. The effects on electrochemical behavior of NaOH treatment and pH were discussed. The results showed that after NaOH treatment increased the electrocatalysis to DA. The electrode was used for detection of DA in the 1×10^-5 mol/L ascorbic acid (AA) in the presence DA. The linear range was 1×10^-8~1.5×10^-7 mol/L, the detection limit was 5.0×10^-9 mol/L. It could effectively removed the disturb of AA.

Abstract: Variamine blue (VB) polymer coatings can be obtained by electrochemical polymerization at glassy carbon electrode. The electrochemical behavior of this stable polymer film at glassy carbon electrode was investigated by cyclic voltammetry. The surface coverage, Γ,the charge transfer coefficient, α , and the charge transfer constant, k_s, for electron transfer between VB and glassy carbon electrode were calculated as 9.0×́10^-5 mol·cm^-2, 0.47, 2.97 s^-1 respectively. This VB polymer coatings modified electrode shows good electrocatalytic activity toward ascorbic acid (AA), uric acid (UA). It can be used in simultaneous determination of AA and UA in a mixture.

Abstract: The poly-histidine (poly-HTD) film was prepared at glassy carbon electrode by electropolymerization, and its electrochemical behavior was investigated by cyclic voltammetry. Results show that the behavior of this poly-HTD film is in good agreement with quasi-reversible process characteristic. At low scan rates, the electronic transfer process of electrode reaction is controlled by surface process. At this poly-HTD film modified electrode, an excellent electrocatalytic ability towards the redox of hydroquinone (HQ) and catechol (CC) with decrease of the overpotential and improvement of the redox peak currents was found. Differential pulse voltammetry was used for the simultaneous determination of HQ and CC in their mixture, and the peak-to-peak separation ΔE_p for HQ and CC was 110 mV. Therefore, this polymer modified electrode can be used for the simultaneously selective determination of HQ and CC without interference with each other.

Abstract: The titanium sol was prepared by depositing the organic titanium on glassy carbon electrode surface. Electrophoresis time and the applied voltage as well can markedly influence the electrochemical behavior of the nanoTiO₂ film. In contrast with bare glassy carbon electrode, the nanoTiO₂ film on glassy carbon electrode had a good electrocatalytic activity to dopamine (DA) and uric acid (UA) in PBS solution. The result showed that there was a linear relationship between the oxidation peak currents and the concentration of DA from 8.0×10^-6 to 4.0×10^-4 mol·L^-1 by differential pulse voltammetry (DPV) and there was a linear relationship between the oxidation peak currents and the concentration of UA from 8×10^-6 to 1.0×10^-3 mol·L^-1. This modified electrode was quite effective to detect DA and UA in simultaneous determination of these species in a mixture.

Abstract: Homogeneous and transparent lanthanum La-doped TiO2 nanocrystalline thin films were deposited on pure titanium substrates by sol gel dip coating method. The surface structures, morphologies and electrocatalytic activities of the prepared nano-TiO2 film electrodes were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Cyclic voltammetry (CV). The results demonstrated that the optimum molar proportion of La was 0.5%. This optimum La-nanoTiO2 electrode (Ti/0.5%La nano-TiO2) showed a higher electrocatalytic activity than the undoped nano-TiO2 electrode (Ti/nano-TiO2)

Abstract: The Ti/PbO₂ electrode doped with Pr₂O₃ was prepared by the electrodeposition method. The X-ray diffraction (XRD) analyses indicated the crystal particles size of Ti/PbO₂/Pr₂O₃ electrode was diminished due to the incorporation of Pr₂O₃ into the film of PbO₂. The scanning electronic microscopy (SEM) revealed that Ti/PbO₂/Pr₂O₃ electrode had smaller particles and larger active surface. The measurement of cyclic voltammograms (CV) revealed Ti/PbO₂/Pr₂O₃ electrode had a better electrochemical properties comparing to Ti/PbO₂ electrode. The bulk electrolysis demonstrated that the Ti/PbO₂/Pr₂O₃ electrode presented excellent electrocatalytic performance for degradation methylene blue.

Abstract: Palladium hollow spheres were synthesized at room temperature using cobalt nanoparticles (NPs) as sacrificing templates. Cobalt NPs can be prepared simply by solvothermal method. The hollow nature of sample Pd were observed from the TEM image and the SAED pattern indicates the polycrystalline nature of the sample. It was found that Pd hollow spheres showed high catalytic activity towards the electrooxidation of alcohols, especially ethanol with the current density up to 2047 mA•mg^-1. The formation mechanism and the structure-property relationship of Pd hollow spheres were discussed based on the experimental results.

Abstract: Activated carbon supported gold nanoparticles (Au/C) were prepared by a chemical reduction process using NaBH₄ as a reducing agent. The characterization of transmission electron microscope indicated that the Au nanoparticles (AuNPs) in the Au/C catalyst were highly well dispersed on the carbon support. The catalytic activity of the Au/C catalyst for the methanol electrooxidation (MEO) was investigated by the cyclic voltammetry (CV). The results displayed that the Au/C catalyst exhibited a favorable catalytic activity towards the MEO in alkaline solution. Moreover, the competitive adsorption between OH^- and CH₃OH on the surface of the AuNPs in the Au/C catalyst existed in the course of the MEO. Based on this competitive adsorption, the mechanism of the MEO on the Au/C catalyst was further investigated.

Abstract: To explore the effect of the electrical degradation of phenolic compounds with TiO₂ under different conditions. The effects of pH, electrode distance, cell voltage, concentration of electrolyte Na₂SO₄ and the initial concentration of phenol were studied for the removal efficiency of phenol. The experiment measured that reacted for 60 min under the conditions that the original solution phenol content is 10 mg/l, the voltage is 15 V, the electrode distance is 1 cm, the electrolyte Na₂SO₄ is 0.2 mol/l, the removal efficiency of the phenol reached 99%.

Abstract: Cobalt hexacynoferrate decorated carbon spheres (CoHCF@C) with few micron dimensions was synthesized by sequential deposition method in which the carbon sphere previously modified with cobalt ion exposed into potassium ferricyanide. The thickness of the CoHCF layer was restricted to five cycles. The formation of layer CoHCF was confirmed by FT-IR, XRD, HRSEM, EDX and cyclic voltammeter technique. The CoHCF decorated carbon sphere modified GCE was utilized as electron transfer mediator for electrocatalytic oxidation of hydrazine in phosphate buffer medium. The electrocatalytic behavior of modified electrode on oxidation of hydrazine is compared with bare GCE. The amperometry method was adapted for the quantitative detection of hydrazine in water samples.