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1.
Annamalai Senthil Kumar K. Chandrasekara Pillai 《Journal of Solid State Electrochemistry》2000,4(7):408-416
Ruthenium dioxide electrodes, prepared on a Pt substrate using coatings of PVC-RuO2 mixed in THF (designated as RuO2-PVC film electrode) have been studied for their redox behaviour in 1 M NaOH using variable scan cyclic voltammetry. The various
redox transitions in the oxidation state of the central metal ion are characterized using electrochemical parameters such
as peak potential, peak current, and surface charge. The effect of oxide preparation temperature, in the range 300–700 °C,
on the redox characteristics has also been studied and correlated with the electrochemically active surface area (as measured
using small amplitude cyclic voltammetry) and the true surface area (by the BET method).
Received: 12 August 1997 / Accepted: 18 October 1999 相似文献
2.
J. Shankara Narayanan C. Anjalidevi V. Dharuman 《Journal of Solid State Electrochemistry》2013,17(4):937-947
Development of nonenzymatic glucose sensors with high reproducibility and stability is an urgent need to reduce cost of regular diabetic monitoring. Here, we have fabricated ruthenium dioxide–poly(vinyl chloride)–Nafion (RuO2–PVC–Nafion) composite for direct glucose sensing in sodium hydroxide and phosphate buffer nonenzymatically for the first time. The restricted activity of the RuO2–PVC film electrode in alkaline pH is extended to neutral pH using Nafion as an outer membrane, which reduces the distance between Ru active sites by bridging effect and improves the electrode stability. The catalytic rate, measured in terms of change of RuO2 resistance, is similar irrespective of the medium for the high temperature annealed RuO2 (700 °C), whereas the low temperature annealed RuO2 (300 °C) is highly sensitive for the change in the pH of the solution. This is revealed by observing large Michaelis–Menten kinetic constant K M for the RuO2 (700 °C) than the low temperature annealed RuO2 (300 °C) due to effective increase in the catalytic active sites similar to oxygen evolution reaction. Contrast to this, the buffer solution does not influence significantly the apparent K M observed for RuO2 (300 °C) and has greater impact on the high temperature 500 and 700 °C annealed RuO2 samples. Cyclic voltammetry, chrono amperommetry, and electrochemical impedance spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction techniques are used for characterization of the sensor behavior. The RuO2–PVC–Nafion senses glucose selectively in the presence of potential interferences like fructose, galactose, mannose, sucrose, starch, uric acid, ascorbic acid, dopamine, and catechol in NaOH and phosphate buffer. Glucose sensing in the blood serum of the diabetic and nondiabetic patients is made. The results suggest that the RuO2–PVC–Nafion is a promising candidate for the development of nonenzymatic glucose sensors. 相似文献
3.
K. Vaarmets S. Sepp J. Nerut E. Härk I. Tallo E. Lust 《Journal of Solid State Electrochemistry》2013,17(6):1729-1741
The electrochemical reduction of oxygen on binary Pt–Ru alloy deposited onto microporous–mesoporous carbon support was studied in 0.5 M H2SO4 solution using cyclic voltammetry, rotating disk electrode (RDE), and impedance method. The microporous–mesoporous carbon support C(Mo2C) with specific surface area of 1,990 m2?g?1 was prepared from Mo2C at 600 °C using the chlorination method. Analysis of X-ray diffraction, photoelectron spectroscopy, and high-resolution transmission electron microscopy data confirms that the Pt–Ru alloy has been formed and the atomic fraction of Ru in the alloy was ~0.5. High cathodic oxygen reduction current densities (?160 A?m?2 at 3,000 rev?min?1) have been measured by the RDE method. The O2 diffusion constant (1.9?±?0.3?×?10?5?cm2?s?1) and the number of electrons transferred per electroreduction of one O2 molecule (~4), calculated from the Levich and Koutecky–Levich plots, are in agreement with literature data. Similarly to the Ru/RuO2 system in H2SO4 aqueous solution, nearly capacitive behavior was observed from impedance data at very low ac frequencies, explained by slow electrical double-layer formation limited by the adsorption of reaction intermediates and products into microporous–mesoporous Pt–Ru–C(Mo2C) catalyst. All results obtained for C(Mo2C) and Pt–Ru–C(Mo2C) electrodes have been compared with corresponding data for commercial carbon VULCAN® XC72 (C(Vulcan)) and Pt–Ru–C(Vulcan) electrodes processed and measured in the same experimental conditions. Higher activity for C(Mo2C) and Pt–Ru–C(Mo2C) has been demonstrated. 相似文献
4.
《Electroanalysis》2003,15(2):97-102
The oxidation of dimethyl sulfoxide (DMSO) to dimethyl sulfone (DMSO2) is representative of numerous anodic oxygen‐transfer reactions of organosulfur compounds that suffer from slow kinetics at noble metal electrodes. Anodic voltammetric data for DMSO are examined at various RuO2‐film electrodes prepared by thermal deposition on titanium substrates. The response for DMSO is slightly larger at RuO2 films prepared in a flame as compared with films prepared in a furnace; however, temperature is more easily controlled in the furnace. Doping of the RuO2 films with Fe(III) further improves the sensitivity of anodic response for DMSO. Optimal response is obtained at an Fe(III)‐doped RuO2‐film electrode prepared using a deposition solution of 50 mM RuCl3 and 10 mM FeCl3 in a 1 : 1 mixture of isopropanol and 12 M HCl at an annealing temperature of 450 °C. The Levich plot (i vs. ω1/2) and Koutecky‐Levich plot (1/i vs. 1/ω1/2) of amperometric data for the oxidation of DMSO at an Fe(III)‐doped RuO2‐film electrode configured as a rotated disk are consistent with an anodic response controlled by mass‐transport processes at low rotational velocities. Flow injection data demonstrate that Fe(III)‐doped RuO2‐film electrodes exhibit detection capability for methionine and cysteine in addition to DMSO. Detection limits for 100‐μL injections of the three compounds are ca. 3.2×10?4 mM, i.e., ca. 32 pmol. 相似文献
5.
J. Juodkazytė R. Vilkauskaitė G. Stalnionis B. Šebeka K. Juodkazis 《Electroanalysis》2007,19(10):1093-1099
The present study represents comparative analysis of voltammetric and microgravimetric behavior of active ruthenium (Ru), electrochemically passivated ruthenium (Ru/RuO2) and thermally formed RuO2 electrodes in the solutions of 0.5 M H2SO4 and 0.1 M KOH. It has been found that cycling the potential of active Ru electrode within E ranges 0 V–0.8 V and 0 V–1.2 V in 0.5 M H2SO4 and 0.1 M KOH solutions, respectively, leads to continuous electrode mass increase, while mass changes observed in alkaline medium are considerably smaller than those in acidic one. Microgravimetric response of active Ru electrode in 0.5 M H2SO4 within 0.2 V–0.8 V has revealed reversible character of anodic and cathodic processes. The experimentally found anodic mass gain and cathodic mass loss within 0.2–0.8 V make 2.2–2.7 g F?1, instead of 17 g F?1, which is the theoretically predicted value for Ru(OH)3 formation according to equation: Ru+3H2O?Ru(OH)3+3H++3e?. In the case of Ru/RuO2 electrode relatively small changes in mass have been found to accompany the anodic and cathodic processes within E range between 0.4 V and 1.2 V in the solution of 0.5 M H2SO4. Meanwhile cycling the potential of thermally formed RuO2 electrode under the same conditions has lead to continuous decrease in electrode mass, which has been attributed to irreversible dehydration of RuO2 layer. On the basis of microgravimetric and voltammetric study as well as the coulometric analysis of the results conclusions are presented regarding the nature of surface processes taking place on Ru and RuO2 electrodes. 相似文献
6.
P.N. Ross K. Kinoshita A.J. Scarpellino P. Stonehart 《Journal of Electroanalytical Chemistry》1975,63(1):97-110
The electrocatalytic properties of Pt+Ru alloys supported on graphitized carbon have been studied using oxide-free metal alloys that have been well characterized for phase identification, specific metal surface area, and surface composition. The CO tolerance of the Pt+Ru alloys for the oxidation of CO contaminated hydrogen in hot concentrated H3PO4 increases monotonically with Ru content of the surface and is a direct result of a decreasing coverage of the alloy by adsorbed CO. Furthermore, the strength of bonding of adsorbed CO with the metal surface decreases dramatically with increasing Ru content in the surface. The absolute activity of Pt+Ru alloys for the oxidation of CO contaminated hydrogen is a complex function of temperature and electrode potential. At 160°C, pure Pt is the most active catalyst at all potentials, but at temperatures lower than 120°C the reaction-limiting current for pure Ru exceeds that of pure Pt. At any temperature from 110–160°C or any electrode potential from 0–0.3V (HE), the variation of electrocatalytic activity with alloy composition indicates only dilution of the activity of the more active component. 相似文献
7.
An electrically heated microelectrode chip (HMEC) was designed and the Ru(bpy)32+/carbofuran electrochemiluminescence (ECL) systems were applied to characterize the performance of the HMEC. The ECL intensities increase at elevated electrode temperature, and the detection limit at 60°C (electrode surface temperature) was about 10 times lower than that at 30°C. The results indicate that new heated electrode can be handled easily and can be mass produced, the difference between the electrodes was little. The stability of the HMEC was good since the electrode surface can hardly be destroyed during detection and storage. 相似文献
8.
《Analytical letters》2012,45(11):1735-1746
Abstract Nanoscale Pt/RuO2 colloid with carbon paste support was synthesized and used to prepare a modified electrode for phenol detection. The results showed that the Pt/RuO2 catalyst has high activity for electrooxidation of phenol with reduced intermediate polymerization due to its significantly low potential for phenol oxidation. The detection limit was as low as 10?9 mol L?1 for the polishable Pt/RuO2/C paste electrode with good reproducibility. 相似文献
9.
Libu Manjakkal Katarina Cvejin Jan Kulawik Krzysztof Zaraska Robert P. Socha Dorota Szwagierczak 《Analytica chimica acta》2016
The paper reports on investigation of the pH sensing mechanism of thick film RuO2-Ta2O5 sensors by using X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). Interdigitated conductimetric pH sensors were screen printed on alumina substrates. The microstructure and elemental composition of the films were examined by scanning electron microscopy and energy dispersive spectroscopy. The XPS studies revealed the presence of Ru ions at different oxidation states and the surface hydroxylation of the sensing layer increasing with increasing pH. The EIS analysis carried out in the frequency range 10 Hz–2 MHz showed that the electrical parameters of the sensitive electrodes in the low frequency range were distinctly dependent on pH. The charge transfer and ionic exchange occurring at metal oxide-solution interface were indicated as processes responsible for the sensing mechanism of thick film RuO2-Ta2O5 pH sensors. 相似文献
10.
RuO2 nanostructures were synthesized by heating Ru nanoparticles in air at 280°C using Cu as catalyst. The Ru nanoparticles were
prepared by the pyrolysis of ruthenium precursors in a vacuum using multi-walled carbon nanotubes as templates. The RuO2 nanostructures grew radically with diameters of 50–150 nm, and lengths of 0.5–2.0 μm. The growth of nanostructure mainly
depends on the dispersivity of Ru nanoparticles on MWNTs. The electrochemical property of these nanostructures was studied
by cyclic voltammetry.
Electronic Supplementary Material Supplementary material for this article is available at and is accessible for authorized users. 相似文献
11.
电催化氧化法处理苯酚废水的Mn-Sn-Sb/γ-Al2O3粒子电极研制 总被引:11,自引:0,他引:11
采用溶胶-凝胶法制备了一系列不同Mn/Sn/Sb比的γ-Al2O3负载型粒子电极, 以苯酚为模型污染物考察了粒子电极的催化活性, 并用BET表面积、SEM和XRD等手段, 对粒子电极的微结构、表面形貌及物相进行了表征. 研究表明, 在Sn和Sb含量相同的情况下, Mn与Sn的摩尔比为2∶1时催化活性最高, 其催化活性远远高于某化学物理所提供的Ru/TiO2粒子电极. 所制粒子电极不仅具有相当高的电催化活性, 而且在使用过程中催化性能稳定, 经5次反复使用后仍具有较高的催化活性. 反应过程中活性组分的流失是粒子电极失活的主要原因, 催化剂表面积炭也可能是粒子电极失活的原因之一. 相似文献
12.
N. M. Bogdanovich D. I. Bronin G. K. Vdovin I. Yu. Yaroslavtsev B. L. Kuzin 《Russian Journal of Electrochemistry》2009,45(4):456-464
The sintering features, electroconductivity, and electrochemical characteristics of bilayer electrodes with functional composite
layers based on La(Sr)MnO3 (LSM) and La(Sr)Fe(Co)O3 with LSM collector layer and Bi(Y)O1.5 (YDB) electrolyte additive in contact with Ce (Sm)O2(SDC), La(Sr)Ga(Mg)O3, and Zr(Sc)O2 electrolytes were studied. YDB additive to the electrode collector layer was shown to produce a positive effect to the properties
of the studied electrode systems. The maximum electrochemical activity and electroconductivity was observed for the electrodes
with 5 wt % of YDB electrolyte additive in the collector layer. Thus, electroconductivity of electrodes is almost doubled
and 100 mV cathode overvoltage current density is increased by 30% at the temperatures of 800 to 900°C and up to 10-fold at
650 to 700°C. The collector layer sintering temperature of bilayer electrodes can be reduced from 1150 to 1000°C without loss
of electrochemical activity. The service life tests (about 1200 h) of composite electrodes with LSM2-SDC functional layer
and 90% LSM2 + 10% YDB collector layer in contact with SDC electrolyte showed the time dependences of polarization resistance
tending to saturation and described with damped exponent.
Original Russian Text ? N.M. Bogdanovich, D.I. Bronin, G.K. Vdovin, I.Yu. Yaroslavtsev, B.L. Kuzin, 2009, published in Elektrokhimiya,
2009, Vol. 45, No. 4, pp. 486–494. 相似文献
13.
《Journal of Electroanalytical Chemistry》1986,199(1):47-68
14.
Paula Díez Ciprian-George Piuleac Paloma Martínez-Ruiz Santiago Romano María Gamella Reynaldo Villalonga José M. Pingarrón 《Analytical and bioanalytical chemistry》2013,405(11):3773-3781
Cysteamine core polyamidoamine G-4 dendron branched with β-cyclodextrins was chemisorbed on the surface of Au electrodes and further coated with Pt nanoparticles. Adamantane-modified glucose oxidase was subsequently immobilized on the nanostructured electrode surface by supramolecular association. This enzyme electrode was used to construct a reagentless amperometric biosensor for glucose, making use of the electrochemical oxidation of H2O2 generated in the enzyme reaction. The amperometric response of the biosensor was rapid (6 s) and a linear function of glucose concentration between 5 and 705 μmol?L?1. The biosensor had a low detection limit of 2.0 μmol?L?1, sensitivity of 197 mA?mol?1?L?cm?2, and retained 94 % of its initial response after storage for nine days at 4 °C. 相似文献
15.
Jelena S. ?or?evi? Ana M. Kalijadis Ksenija R. Kumri? Zoran M. Jovanovi? Zoran V. Lau?evi? Tatjana M. Trti?-Petrovi? 《Central European Journal of Chemistry》2012,10(4):1271-1279
In this study the application of home-made unmodified (GC) and bulk modified boron doped glassy carbon (GCB) electrodes for the voltammetric determination of the linuron was investigated. The electrodes were synthesized with a moderate temperature treatment (1000°C). Obtained results were compared with the electrochemical determination of the linuron using a commercial glassy carbon electrode (GC-Metrohm). The peak potential (E p ) of linuron oxidation in 0.1 mol dm−3 H2SO4 as electrolyte was similar for all applied electrodes: 1.31, 1.34 and 1.28 V for GCB, GC and GC-Metrohm electrodes, respectively. Potential of linuron oxidation and current density depend on the pH of supporting electrolyte. Applying GCB and GC-Metrohm electrodes the most intensive electrochemical response for linuron was obtained in strongly acidic solution (0.1 mol dm−3 H2SO4). Applying the boron doped glassy carbon electrode the broadest linear range (0.005–0.1 μmol cm−3) for the linuron determination was obtained. The results of voltammetric determination of the linuron in spiked water samples showed good correlation between added and found amounts of linuron and also are in good agreement with the results obtained by HPLC-UV method. This appears to be the first application of a boron doped glassy carbon electrode for voltammetric determination of the environmental important compounds. 相似文献
16.
M. R. Tarasevich E. S. Davydova A. D. Modestov L. P. Kazanskii Hongting Pu 《Russian Journal of Electrochemistry》2012,48(1):82-88
A number of catalysts of the (Ru-Ni)/C system is synthesized and studied for application in anodes of alkaline ethanol-air
fuel cells. The carbon supports used are carbon blacks with different specific surface area and graphite powders. The X-ray
photoelectron spectroscopy technique allowed detecting on the catalyst surface metallic ruthenium and nickel in the form of
Ni(OH)2 hydroxide and possibly oxyhydroxide NiOOH. It is shown that the catalyst activity in the reaction of ethanol electrochemical
oxidation grows at an increase in the specific surface area of the carbon support. The method of carbon monoxide oxidative
desorption was used to determine the values of the specific surface area of the catalyst metallic phase. It is shown that
at an increase in the relative ruthenium content from (1Ru3Ni)/C to Ru/C, the specific catalytic activity in the catalysts
of the (Ru-Ni)/C system reaches the maximum value near the composition of (2Ru1Ni)/C. It is shown that the found optimum catalyst
composition is independent of the carbon support dispersion degree. Activity in ethanol electrooxidation of the (2Ru1Ni)/C
catalyst supported on the Ketjenblack EC-600 carbon black is 18 ± 3 A/g of the catalyst (>120 A/g of Ru) at 40°C and potential
E = 0.5 V in the 2MKOH + 1 M C2H5OH electrolyte. 相似文献
17.
In a CO−O2 stoichiometric mixture, the kinetic parameters, reaction order, rate constant and activation energy of CO oxidation over
a Pt/SnO2 catalyst have been measured using a fixed bed flow reactor near 0°C. The results show that it is a first-order reaction.
The activation energy of CO oxidation over Pt/SnO2 prepared with SnO2 calcined at 300°C was approximately 21 kJ/mol. The activation energy of CO oxidation over Pt/SnO2 changed slowly with SnO2 calcination temperature above 400°C, and reached approximately 45 kJ/mol. 相似文献
18.
Marek Mooste Elo Kibena Ave Sarapuu Uno Mäeorg Gilberto Maia Kaido Tammeveski 《Journal of Solid State Electrochemistry》2014,18(6):1725-1733
Anthraquinone groups were electrochemically grafted to glassy carbon (GC) electrodes via methylene linker to study the oxygen reduction reaction (ORR) in alkaline medium. Two different anthraquinone derivatives, 2-bromomethyl-anthraquinone or 2-chloromethyl-anthraquinone, were used to modify the GC electrode surface. Several modification conditions encompassing potential cycling and electrolysis at a fixed potential were employed in order to vary the surface concentration of MAQ groups (Γ MAQ) and to study the dependence of the O2 reduction behaviour on electrografting procedure. Cyclic voltammetry confirmed the presence of anthraquinone moieties attached to the GC electrode and Γ MAQ varied in the range of (0.5–2.4)?×?10?10 mol cm?2. Oxygen reduction was studied on MAQ-modified GC electrodes of various surface coverage using the rotating disc electrode (RDE) and rotating ring-disc electrode (RRDE) methods. The RDE and RRDE results of O2 reduction reveal that GC/MAQ electrodes show rather similar electrocatalytic behaviour towards the ORR yielding hydrogen peroxide as the final product. 相似文献
19.
We report the studies on a flexible quasi-solid-state configuration of the redox supercapacitors (pseudocapacitors) assembled with an ionic liquid-based proton conducting non-aqueous gel polymer electrolyte (ILGPE) and composite electrodes of conducting polymer [poly-3-methyl thiophene (pMeT)] and hydrous ruthenium dioxide (RuO2.xH2O). The presence of RuO2.xH2O in the composite electrodes has been confirmed by X-ray diffraction and thermogravimetric analysis. The ILGPE films, prepared with the solution of an ionic liquid (1-ethyl 3-methyl imidazolium trifluoromethanesulfonate) and a salt ammonium trifluoromethanesulfonate entrapped in a host polymer poly(vinylidene fluoride-co-hexafluoropropylene), have been characterized. The symmetrical pseudocapacitors have been assembled and characterized using electrochemical impedance spectroscopy, cyclic voltammetry, and charge–discharge tests. The composite electrodes with the ~13 wt.% hydrous RuO2 loading in pMeT film has shown a maximum specific capacitance value of ~118 F g?1 (of the composite electrode material). The corresponding maximum specific energy and power density have been found to be ~12.8 W kg?1 and ~513 W kg?1, respectively. With further increase in the content of RuO2.xH2O, a slight decrease in specific capacitance value has been observed, which indicates the reduction in utilization rate of RuO2.xH2O. The composite electrodes show stable capacitance values up to 5,000 charge–discharge cycles. 相似文献
20.
V. Balek T. Mitsuhashi J. Šubrt P. Bezdička J. Fusek 《Journal of Thermal Analysis and Calorimetry》2000,60(2):691-698
Emanation Thermal Analysis (ETA) was used to characterize microstructure changes of hydrous ruthenia and hydrous ruthenia-titania
as precursors for preparation of RuO2 and (RuO2)0.9-(TiO2)0.l by heating in the temperature range of 20–600°C in argon. A good agreement was found between ETA, TG and DTA results, X-ray
diffraction patterns and surface area measurements of intermediate products of the thermal treatment.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献