The effect of transition metal ions (M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)) on the chemical synthesis polyaniline as counter electrodes in dye-sensitized solar cells

The effect of transition metal ions(M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)) on the chemical synthesis of polyaniline(PANI) used as a platinum-free counter electrode(CE) in dye-sensitized solar cells(DSSCs) was investigated.PANI was synthesized by co-polymerization of aniline in the presence of different transition metal ions by using potassium dichromate in acidic medium. It was found that the ion doping of PANI showed a certain catalytic activity for the regeneration of traditional iodide/triiodide(I^-/I_3^-) redox couples. The power conversion efficiency(η) of PANI CEs doped with Mn^(2+),Ni^(2+),Co^(2+) (4.41%, 2.36% and 2.10%, respectively) were higher than 1.94%, the value measured for PANI CE without doping. Doping with Cu^(2+)decreased the power conversion efficiency of PANI CE(PANI-Cu^(2+) η = 1.41%). The electrical properties of the PANI, PANI-Ni^(2+), PANI-Co^(2+),PANI-Mn^(2+) and PANI-Cu^(2+) were studied by cyclic voltammetry(CV), impedance(EIS), and Tafel polarization curve. The experimental results confirmed that PANI was affected by the doping of different transition metal ions(M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)). These results indicate a potential application of ion doped PANI as counter electrode in cost-effective DSSCs.

STUDY OH PHo_(12)O_(40)^(3-)-POLYANILINE MODIFIED ELECTRODE

Electrochemical Betted not only can obtain the conducting film of polyaniline on a glass carbon electrode, but also can imobilize PMo_(12)O_(40)^(3-) in the film to form a organic conducting film electrode modified by heteropolyanion.The paper here reports electrochemical changes in the preparation of PMo_(12)O_(40)^(3-)-polyaniline modified electrode, the electrochemical reaction mechanism of the modified electrode was obtained from the study on its redox properties.Moreover, the above electrode showed marked electrocatalysis for the reduction reaction of CIO_(?)^-.

Effect of Rotation Rate on the Formation of Platinum-modified Polyaniline Film and Electrocatalytic Oxidation of Methanol

The oxidation of methanol was investigated on platinum-modified polyaniline electrode. Changes in the electrode rotation rates (Ω) during platinum electrodeposition remarkably affect the formation and distribution of platinum in the polymer matrix and consequently lead to different currents of methanol oxidation. The results show that platinum loading is proportional to rotation ratesΩ1/2.

Photo-Corrosion of CdSe Film Electrode by Electrochemical Modulation Reflectance Spectrum

The photo-corrosion of electrodeposited polycrystalline CdSe electrode was inhibited effectively by coating a thin layer of the conductive polyaniline （PAN） film. The relation between the performance and internal band structure of such film-covered PAN/CdSe electrode was studied by the electrochemical modulation reflectance spectrum （EMRS）. EMRS of both CdSe and PAN/CdSe electrodes in K4Fe（CN）6/K3Fe（CN）6 solution exhibited typical France-Keidysh oscillations, by which the values of the energy gap and flat band potential were determined. The EMRS results indicated that the energy band structure of CdSe electrode was not changed after coated with PAN film, so that the photoelectrochemical characteristic of PAN/CdSe electrode was rather similar to that of CdSe electrode.

Catalysis of dioxygen reduction at soluble polyaniline modified electrode

A reflux-treatment of soluble polyaniline(SPA)in dimethylformamide(DMF)containing CoCl_2 yields an active catalyst for dioxygen reduction which can be adsorbed on the electrode surface firmly.The catalytic reduction of dioxygen at the glassy carbon(GC)electrode modified by the cata- lyst was studied with cyclic voltammetry(CV),rotating disk electrode(RDE)and rotating ring-disk electrode(RRDE).The kinetic process of dioxygen reduction at the modified electrode was analyzed with a new RRDE theory dealing with a nondiffusion-controlled process on ring electrode.The rate constants for each scheme of dioxygen reduction were calculated,showing that only 2-electron reduction to H_2O_2 was conducted at the modified electrode.The effect of solution acidity on the electrocatalytic behaviour for dioxygen reduction was investigated.A possibility of initiating catalytic activity for dioxygen reduction was explored with ESCA method.