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A simple but effective electrochemical route to functionalize graphene is demonstrated. Cyclic voltammetric sweeps are performed in 0.5 M H2SO4 aqueous solution on electrodes containing carbon cloth, graphene, and Nafion ionomer. With supply of ambient oxygen, the formation of hydroxyl radicals from the oxygen reduction reaction during CV cycles initiates the decomposition of Nafion ionomer that engenders oxygenated functional groups on the graphene surface. Raman analysis suggests a minor change for the graphene structure. Exploring various amounts of Nafion ionomer, we determine the optimized conditions for graphene functionalization. Contact angle is used to evaluate the effect of Nafion ionomer decomposition. X-ray photoelectron spectroscopy is employed to study relevant functional groups. Afterwards, nanoparticles of Pd9Ru are synthesized and impregnated on those functionalized graphene (FGN) via a wet chemical reflux process. X-ray diffraction patterns of the as-synthesized samples suggest successful formation of alloy without presence of individual Pd and Ru nanoparticles. Images from transmission electron microscope confirm the average size of 3-4 nm. Subsequently, the Pd9Ru/FGN undergoes Cu under potential deposition, followed by a galvanic displacement reaction to deposit a Pt monolayer on the Pd9Ru surface (Pd9Ru@Pt). Intensive experimental work is ongoing to investigate the electrochemical active surface area (ECSA) and electrocatalytic activities of Pd9Ru@Pt/FGN.

Fabrication of graphene was demonstrated by electrochemical exfoliation of graphite in an ammonium hydroxide solution. The processing parameter of applied voltage was optimized to accomplish graphene productivity and desired chemical composition. Images from the atomic force microscopy showed graphene sheets with lateral sizes of several hundred nanometers. Images from the transmission electron microscopy indicated the existence of stacked graphene sheets with thickness of a few graphene layers. Raman spectroscopy confirmed variation of as-synthesized graphene and bulk graphite. X-ray photoemission spectroscopy suggested the formation of graphene oxide at large voltage.

We report a facile electrochemical method to produce functional groups on the carbon surface in which multiple cyclic voltammetric (CV) sweeps are imposed in 0.5 M H2SO4 electrolyte on the samples containing carbon cloth, Vulcan XC72R, and Nafion ionomer. With supply of ambient O2, the generation of radicals from the oxygen reduction and Nafion ionomer degradation enables an accelerated formation of oxygenated functional groups on the carbon surface. Raman analysis reveals structural variation for the carbon electrodes after CV modifications. X-ray photoelectron spectroscopy confirms the alteration of carbon structure in conjunction with notable increase of oxygenated groups and reduction in fluorine amount. The functionalized electrodes allow a 250% increment for PtRu electrodeposition as compared to the reference sample. We carry out electrochemical measurements on methanol electro-oxidation for the PtRu samples. The functionalized electrode demonstrates significant improvement in apparent current density and mass activity as opposed to the reference sample.

A tri-layered ceramic structure was prepared by consecutive electrophoretic depositions of anode, electrolyte, and cathode, followed by a single sintering process to fabricate solid oxide fuel cells. Materials characterizations including SEM and XRD were carried out along with electrochemical analysis.

Synthesis of various sizes particulate Ag supported on carbon nanocapsules (CNCs) were conducted in typical impregnation and wet chemical approach for physical characterization and electrochemical analysis in alkaline electrolyte. XRD of the as-synthesized powders indicated Ag in FCC phase. In i-V polarizations, the nano Ag/CNCs derived wet chemical route exhibited much enhanced oxygen reduction reaction capabilities than those of Ag/CNCs from impregnation method. Similar behaviors were recorded in galvanostatic discharging measurements between 10 and 200 mA/cm2.

A galvanostatic pulse electrodeposition technique of preparing nanoparticulate PtRu electrocatalyst for direct methanol fuel cells has been demonstrated. After extensive cyclic voltammetric analysis, we determined the optimized parameters for the methanol oxidation to be current on-time on 50 ms, current off-time of 400 ms, current density of 50 mA/cm2, and total charge of 8.0 C/cm2. In addition, the catalyst loading was measured at 68 μg/cm2, resulting in a mass activity of 213 mA/Pt.mg. The composition for the nanoparticles was confirmed as Pt65Ru35. High-magnification images on the specimen indicated fine particles in 4-20 nm with uniform distributions.

Synthesis of nanoparticulate Pt and PtRu were conducted in typical wet chemical approach on carbon nanocapsules (CNCs) and VXC72R for electrochemical characterization in acidic electrolyte. XRD of the as-synthesized powders indicated Pt and PtRu in FCC phase with particle sizes around 2~15 nm. Cyclic voltammetry of Pt/CNCs and PtRu/CNCs was analyzed for hydrogen oxidation reaction, revealing impressive catalytic power. In contrast, Pt/VXC72R and PtRu/VXC72R demonstrated moderately reduced performance. Our work suggested CNCs to be superb material as electrocatalyst support.