Probe beam deflection study of the ion exchange between Prussian blue film or indium hexacyanoferrate film and electrolyte solutions

Probe beam deflection(PBD) technique together with electrochemical techniques such as cyclic voltammetry was used to study the ion exchange in prussian blue(PB) film and its analogue indium hexacyanoferrate (InHCF) chemically modified electrodes, The ion exchange mechanism of PB was verified as following: K2Fe2+FeI(CN)(6)(-e--K+)reversible arrow(+e-+K+)KFe(3+)Fe(I)(CN)(6)(-xe--xK+)reversible arrow(+xe-+xK+) [Fe3+FeI(CN)(6)](x)[KFe3+FeI(CN)(6)](1-x) where on reduction in contact with an acidic KCl electrolyte, H+ enter PB film before K+. Both the cations and anions participate concurrently in the redox process of InHCF, meanwhile K+ ion plays a major role in the whole charge transfer process of this film with increasing radii of anions.

ELECTROCATALYTIC OXIDATION AND AMPEROMETRIC DETERMINATION OF SULFHYDRYL COMPOUNDS AT A COPPER HEXACYANOFERRATE FILM GLASSY-CARBON ELECTRODE IN LIQUID-CHROMATOGRAPHY

Electrocatalytic oxidation of sulfhydryl compounds was effective on a copper hexacyanoferrate (CuHCF) film glassy carbon electrode, at a significantly reduced overpotential (0.55 to 0.65 V) and for a broader pH range (2.0 to 7.0). The electrocatalysis was

CUPRIC HEXACYANOFERRATE COLLOID DOPED POLYPYRROLE FILM-MODIFIED ELECTRODE

Anionic colloid cupric hexacyanoferrate (CuHCF) was incorporated into polypyrrole (PPy) films in the course of electrochemical polymerization of pyrrole from aqueous solution containing pyrrole and CuHCF colloid. The films obtained were dark brown in color. Three redox peaks appeared in the cyclic voltammogram (CV). The peaks around 0.7 V (vs, SCE) showed cation-selective properties. X-ray photoelectron spectroscopic analysis and ultraviolet-visible (UV-vis) spectroscopic properties of the film were investigated.

ELECTROCHEMICAL-BEHAVIOR OF HEXACYANOFERRATE(II) ON A GOLD ELECTRODE MODIFIED WITH BIS(4-PYRIDYL)DISULFIDE

The electrochemical behaviour of hexacyanoferrate(II) has been studied by using a bis(4-pyridyl)disulfide modified gold electrode. On the protonated electrode surface, hexacyanoferrate(II) can transfer an electron reversibly but no apparent adsorption was detected. On the deprotonated electrode surface, electron transfer by hexacyanoferrate(II) was more difficult. The electrochemical reversibility varied with the pH of the solution. Relationships between the currents or the standard heterogeneous rate constants and pH were derived.

TRANSPORT OF ELECTROACTIVE SPECIES FE-2+ THROUGH THIN-FILMS OF VANADIUM HEXACYANOFERRATE

It is demonstrated that the electroactive species Fe~(2+) ion can transport easily through the thin films of vanadium hexacyanoferrate (VHF) to the underlaying glassy carbon (GC)electrode surface to be oxidized directly at less positive potential and that it can also be oxidized at the film at more positive potential through the media- tion of redox sites in the film. These two processes yield sequentially clearly distinguished first and second wave in stationary current-potential curves resulting...

铁氰化钴修饰电极的制备、表征及电催化性能的研究

多核过渡金属铁氰化物修饰电极的研究在电催化、电色显示器件、能量存储、离子识别等方面具有重要的意义。本文采用了电化学的循环伏安法（CV）、旋转圆盘电极技术（RDE）、傅立叶变换红外光谱法（FTIR）和扫描电子显微镜技术（SEM），系统研究了一类铁氰化物—铁氰化钴修饰玻碳（CoHCF／GC）电极的制备方法及其对神经递质多巴胺（DA）的电催化作用以及修饰溶液中一种阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）的加入对所制备的CoHCF／GC电极的电化学性能和电催化性能的影响。主要内容和结论如下：1．改进了CoHCF／GC电极的制备方法。新方法具有简单易行、不受修饰物浓度干扰、修饰时间短、修饰量易于控制等优点，且制备的CoHCF粒径小、结构明确、电化学性能稳定。2．研究了CoHCF／GC电极对DA氧化的电催化性能。采用RDE测定了CoHCF／GC电极对DA的电催化氧化的动力学参数。结果表明用新方法制备的修饰电极对DA氧化有更好的电催化性能。3．研究了在修饰溶液中加入临界浓度的CTAB对所制备的CoHCF／GC电极的影响。CV的研究结果表明，CTAB的加入，基本不影响CoHCF／GC的氧化还原峰峰电位，却使其氧化还原峰峰电流明显增大，且使所制得CoHCF／GC电极对DA氧化表现出不同的电催化行为。FTIR研究表明，CTAB不吸附在电极表面，不改变COHCF膜的化学组成和结构。SEM研究结果表明，CTAB的加入使所制备的CoHCF膜长得更快，更厚，使CoHCF粒子长得更大。因此，可得出结论为CoHCF粒子的大小是影响其对DA不同的电催化行为的主要因素。4．用RDE技术测定了有、无CTAB情况下制备的CoHCF／GC电极对DA的电催化反应的动力学参数。结果表明，有CTAB时制备的CoHCF／GC电极对DA的表观动力学常数kΓ比没有时的要大。

Fabrication and electrochemical characterization of electrostatic assembly of polyelectrolyte-functionalized ionic liquid and Prussian blue ultrathin films

Polyelectrolyte-functionalized ionic liquid (PFIL) and Prussian blue (PB) nanoparticles were used to fabricate ultrathin films on the ITO substrate through electrostatic layer-by-layer assembly method. Multilayer growth was examined by UV-vis spectroscopy and cyclic voltammetry. The resulting ITO/(PFIL/PB)n electrode showed two couples of well-defined redox peaks and good electrocatalytical activity towards the reduction of hydrogen peroxide.

Synthesis and characterization of Prussian blue@platinum nanoparticle hybrids from a mixture solution of platinum nanocatalyst and ferric ferricyanide

In the present study, platinum nanoparticles modified with Prussian blue (PB) have been synthesized by a heterogeneous catalytic reaction. Transmission electronic microscopy (TEM) confirmed the deposition of nanoclusters around the Surfaces of platinum particles, and spectroscopic studies verified that the molecular composition of the nanoclusters was dominantly PB and a minority of platinum ferricyanide. Thus, it was shown that the platinum particles behaved not only as catalysts for the growth of PB, but also as a reactant to generate a PB analogue complex.

A novel urchinlike gold/platinum hybrid nanocatalyst with controlled size

In this paper, we have explored a simple and new strategy to obtain quasimonodisperse Au/Pt hybrid nanoparticles (NPS) with urchinlike morphology and controlled size and Pt shell thickness. Through changing the molar ratios of Au to Pt, the Pt shell thickness of urchinlike Au/Pt hybrid NPs could be easily controlled; through changing the size of Au NPs (the size was easily controlled from similar to 3 to similar to 70 nm via simple heating of HAuCl4-citrate aqueous solution), the size of urchinlike Au/Pt hybrid NPs could be facilely dominated. It should be noted that heating the solution (100 degrees C) was very necessary for obtaining three-dimensional (3D) urchinlike nanostructures while H2PtCl6 was added to gold NPs aqueous solution in the presence of reductant (ascorbic acid). The electrocatalytic oxygen reduction reaction (ORR, a reaction greatly pursued by scientists in view of its important application in fuel cells) and the electron-transfer reaction between hexacyanoferrate(III) ions and thiosulfate ions of urchinlike Au/Pt hybrid NPs were investigated. It is found that the as-prepared urchinlike Au/Pt hybrid NPs exhibited higher catalytic activities than that of similar to Pt NPs with similar size.

"Green synthesis" of monodisperse Pt nanoparticles and their catalytic properties

A green synthetic strategy to prepare monodisperse Pt nanoparticles was reported. Aminodextran acted as the reductive and protective agents, and Pt nanoparticles were characterized by UV/vis spectroscopy (UV-vis), Pt nanoparticles were conveniently obtained at one step. transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). By changing the initial molar ratio of arninodextran to platinum precursor, Pt nanoparticles with different size were obtained. Amino groups of aminodextran could absorb on Pt nanoparticles surfaces and serve as a very good stabilizer. However, dextran without amino groups could not effectively stabilize Pt nanoparticles and aggregation of Pt nanoparticles were obtained. Catalytic activity of these Pt nanoparticles for the electron-transfer reaction between hexacyanoferrate (III) ions and thiosulfate ions was also studied, and they showed good catalytic efficiency.

Assembly process of CuHCF/MPA multilayers on gold nanoparticles modified electrode and characterization by electrochemical SPR

Gold nanoparticles were deposited onto 2-mercaptoethylamine (MEA)-assembled planar gold thin film to construct gold nanoparticles modified electrode by virtue of a solution-based self-assembly strategy. Subsequently, 3-mercaptopropionic acid (MPA)-bridged copper hexacyanoferrate (CuHCF) multilayers were constructed on the as-prepared gold nanoparticles modified electrode. The resulted multilayer nanostructures were investigated by electrochemical surface plasmon resonance (EC-SPR) and atomic force microscopy (AFM) with primary emphasis upon the effect of the gold nanoparticles on the MPA/CuHCF multilayers growth and their surface morphology. Compared with the multilayer system on a planar gold electrode, the different electrochemical and optical properties might result from higher curvature effect and extraordinary surface-to-volume ratio characteristic of gold nanoparticles and the nanoparticle-selective growth of CuHCF. A dendrimer-like assembly process was proposed to explain the experiment results. This new motif of multilayer on the gold nanoparticles modified electrode was different from that of on a planar gold electrode, indicating a potential application of EC-SPR technique in the study of nanocomposite materials.

Carboxyl-cored dendrimer and toluene-assisted fabrication of uniform platinum nanodendrites at a water/oil interface and their potential application as a catalyst

Uniform platinum nanodendrites have been prepared at a water/oil interface by a facile catalyst-free method at room temperature. This is carried out by introducing NaBH4 into the platinum precursor solution in the presence of the second generation of carboxyl-cored dendrimer ([G-2]-CO2H dendrimer) and toluene to act as a protective agent and a linker, respectively. The average fractal dimension of 1.61 of the obtained platinum nanodendrites is calculated by analysing the transmission electron micrographs using the programs Fractal Dimension Version 1.1 and Fractal Dimension Calculator. Control experiments show that the fabrication of platinum nanodendrites can be operated with a wide parameter window, which undoubtedly raises the degree of control of the synthesis process. The potential application of such a nanostructure as a catalyst is investigated, and the results reveal that they show highly efficient catalytic properties for the typical redox reaction between hexacyanoferrate (III) and thiosulfate ions at 301 K.