Microwave-polyol synthesis of nanocrystalline ruthenium oxide nanoparticles on carbon nanotubes for electrochemical capacitors

Abstract The ruthenium oxide nanoparticles dispersed on multi-wall carbon nanotubes (CNTs) were successfully synthesized via microwave-polyol process combined with forced hydrolysis without additional thermal oxidation or electrochemical oxidation treatment. The HRTEM, Raman spectra and TGA curve indicate that CNTs were uniformly coated with crystalline and partially hydrous RuO 2 ·0.64H 2 O nanoparticles of 2 nm diameter and the loading amount of ruthenium oxide in the composite could be controlled up to 70 wt.%. The specific capacitance was 450 Fg −1 of ruthenium oxide/CNT composite electrode with 70 wt.% ruthenium oxide at the potential scan rate of 10 mV s −1 and it decreased to 362 Fg −1 by 18% at 500 mV s −1 . The specific capacitance of ruthenium oxide in the composite was 620 Fg −1 of ruthenium oxide at 10 mV s −1 . The ruthenium oxide nanoparticles in ruthenium oxide/CNT nanocomposite electrode had a high ratio of outer charge to total charge of 0.81, which confirmed its high-rate capability of the composite through the preparation of the nano-sized ruthenium oxide particles on the external surface of CNTs.

[1]  C. Kappe,et al.  Controlled microwave heating in modern organic synthesis. , 2004, Angewandte Chemie.

[2]  S. Komarneni,et al.  Microwave-polyol process for metal nanophases , 2004 .

[3]  S. Ardizzone,et al.  "Inner" and "outer" active surface of RuO2 electrodes , 1990 .

[4]  O. Acher,et al.  Heterogeneous nucleation and growth of metal nanoparticles in polyols , 2001 .

[5]  Ji Liang,et al.  Controlled electrochemical oxidation for enhancing the capacitance of carbon nanotube composites , 2005 .

[6]  S. Trasatti,et al.  Electrochemical surface properties of Co3O4 electrodes , 1987 .

[7]  Phillip E. Savage,et al.  Organic Chemical Reactions in Supercritical Water. , 1999, Chemical reviews.

[8]  Yong‐Tae Kim,et al.  Highly dispersed ruthenium oxide nanoparticles on carboxylated carbon nanotubes for supercapacitor electrode materials , 2005 .

[9]  N. Miura,et al.  Electrochemically deposited nanowhiskers of nickel oxide as a high-power pseudocapacitive electrode , 2004 .

[10]  J. Amarilla,et al.  Amorphous carbon nanofibres inducing high specific capacitance of deposited hydrous ruthenium oxide , 2009 .

[11]  R. C. Bansal,et al.  Removal of copper from aqueous solutions by adsorption on activated carbons , 2001 .

[12]  Chi-Chang Hu,et al.  Electrochemical characterization of activated carbon–ruthenium oxide nanoparticles composites for supercapacitors , 2004 .

[13]  Jun Lin,et al.  One-Step Aqueous Solvothermal Synthesis of In2O3 Nanocrystals , 2008 .

[14]  Jiawen Ren,et al.  Preparation of Tractable Platinum, Rhodium, and Ruthenium Nanoclusters with Small Particle Size in Organic Media , 2000 .

[15]  John R. Owen,et al.  A High-Performance Supercapacitor/Battery Hybrid Incorporating Templated Mesoporous Electrodes , 2003 .

[16]  Jae Hyun Kim,et al.  Synthesis and Characterization of Electrochemically Prepared Ruthenium Oxide on Carbon Nanotube Film Substrate for Supercapacitor Applications , 2005 .

[17]  S. Grugeon,et al.  Synthesis of monodisperse Au, Pt, Pd, Ru and Ir nanoparticles in ethylene glycol , 1999 .

[18]  M. Ortner,et al.  Differential Thermal Analysis and Thermogravimetric Analysis of Fission Product Oxides and Nitrates to 1500° C. , 1961 .

[19]  C. O'connor,et al.  Reactivity of 3d transition metal cations in diethylene glycol solutions. Synthesis of transition metal ferrites with the structure of discrete nanoparticles complexed with long-chain carboxylate anions. , 2002, Inorganic chemistry.

[20]  J. H. Chen,et al.  A new method to prepare RuO2 · xH2O/carbon nanotube composite for electrochemical capacitors , 2005 .

[21]  Yingke Zhou,et al.  Nanocrystalline NiO as an electrode material for electrochemical capacitor , 2004 .

[22]  Chi-Chang Hu,et al.  How to Achieve Maximum Utilization of Hydrous Ruthenium Oxide for Supercapacitors , 2004 .

[23]  J. A. Ritter,et al.  Characterization of Sol‐Gel‐Derived Cobalt Oxide Xerogels as Electrochemical Capacitors , 1998 .

[24]  C. Kappe,et al.  Microwave-assisted synthesis in water as solvent. , 2007, Chemical reviews.

[25]  M. Chehimi,et al.  Acetate- and thiol-capped monodisperse ruthenium nanoparticles: XPS, XAS, and HRTEM studies. , 2005, Langmuir : the ACS journal of surfaces and colloids.

[26]  C. O'connor,et al.  Synthesis of Variable-Sized Nanocrystals of Fe3O4 with High Surface Reactivity , 2004 .

[27]  D. Bang,et al.  Properties of surface‐modified multiwalled carbon nanotube filled poly(ethylene terephthalate) composite films , 2008 .

[28]  S. Trasatti,et al.  Ruthenium dioxide: a new electrode material. I. Behaviour in acid solutions of inert electrolytes , 1974 .

[29]  S. Trasatti,et al.  Ruthenium dioxide: A new interesting electrode material. Solid state structure and electrochemical behaviour , 1971 .

[30]  O Ok Park,et al.  Carbon nanotube/RuO2 nanocomposite electrodes for supercapacitors , 2003 .

[31]  Chi-Chang Hu,et al.  Textural and capacitive characteristics of hydrothermally derived RuO2·xH2O nanocrystallites : Independent control of crystal size and water content , 2007 .

[32]  Xiaogang Zhang,et al.  Synthesis and utilization of RuO2·xH2O nanodots well dispersed on poly(sodium 4-styrene sulfonate) functionalized multi-walled carbon nanotubes for supercapacitors , 2009 .

[33]  Jae-Hong Kim,et al.  Fabrication and electrochemical properties of carbon nanotube film electrodes , 2006 .

[34]  G. Chow,et al.  Nanocrystalline metallic powders and films produced by the polyol method , 1995 .

[35]  Zhu-de Xu,et al.  Synthesis of Ru/carbon nanocomposites by polyol process for electrochemical supercapacitor electrodes , 2006 .

[36]  K. Kobayakawa,et al.  Electrochemical Behavior of Activated‐Carbon Capacitor Materials Loaded with Ruthenium Oxide , 1999 .

[37]  Ralph E. White,et al.  Synthesis and Characterization of Hydrous Ruthenium Oxide-Carbon Supercapacitors , 2001 .

[38]  Nobuhiro Ogihara,et al.  Encapsulation of Nanodot Ruthenium Oxide into KB for Electrochemical Capacitors , 2009 .

[39]  A. Reddy,et al.  Nanocrystalline Metal Oxides Dispersed Multiwalled Carbon Nanotubes as Supercapacitor Electrodes , 2007 .

[40]  Karen E. Swider-Lyons,et al.  Local Atomic Structure and Conduction Mechanism of Nanocrystalline Hydrous RuO2 from X-ray Scattering , 2002 .