51 research outputs found
The PHENIX Experiment at RHIC
The physics emphases of the PHENIX collaboration and the design and current
status of the PHENIX detector are discussed. The plan of the collaboration for
making the most effective use of the available luminosity in the first years of
RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program
available at http://www.rhic.bnl.gov/phenix
Platinum Integrated Graphene for Methanol Fuel Cells
Uniform and porous graphene nanoflake films (GNFs) have been investigated as a support for catalytic Pt nanoclusters in direct methanol electro-oxidation. Pt nanoclusters of varying thickness are deposited on GNFs using magnetron sputtering, and their effects on the electrocatalytic activity for oxidizing methanol are systemically studied. GNF supported Pt nanoclusters with ultralow catalyst loading exhibit high performance for methanol electrocatalytic oxidation with a large mass-specific peak current density and a ratio of forward to backward peak currents up to 1.4. These characteristics compare favorably to the majority of Pt−C based electrodes, except for those of carbon nanotubes with Pt decoration on both the inner and the outer wall surfaces. The results obtained are ascribed to a highly coupled network made of high-density 2−4 nm Pt monolayer nanoclusters on both the basal and edge planes of each nanoflakes of graphene. GNFs are a promising support material for developing next-generation advanced Pt based fuel cells and their relevant electrodes in the field of energy
The effects of electrode and catalyst selection on microfluidic fuel cell performance
A fuel cell can be best defined as an electrochemical
converter of fuel and oxidant of chemical energy to
electrical energy. The important components of
micro fuel cells are the electrodes and catalysts
because the kinetics and rates of the electrochemical
reactions depend on their materials. All fuel cells
consist of two electrodes: the anode, where fuel oxidation takes place, and the cathode, which is used to
reduce the oxidants. The present review article
highlights the use of a range of electrodes made up
of different materials, a variety of catalysts that have
been used in previous studies, and their fabrication
materials and approaches. In this article, electrodes
and catalysts are classified into two types based on
the design approach applied to produce the micro
fuel cell: micro fuel cell design and conventional
assembly design. Most previous studies on fuel cells
have demonstrated that the construction and position of the electrodes play crucial roles in improving
the performance of micro fuel cells
Topochemical conversion of a dense metal-organic framework from a crystalline insulator to an amorphous semiconductor
The topochemical conversion of a dense, insulating metal–organic framework (MOF) into a semiconducting amorphous MOF is described. Treatment of single crystals of copper(I) chloride trithiocyanurate, CuICl(ttcH3) (ttcH3 = trithiocyanuric acid), 1, in aqueous ammonia solution yields monoliths of amorphous CuI1.8(ttc)0.6(ttcH3)0.4, 3. The treatment changes the transparent orange crystals of 1 into shiny black monoliths of 3 with retention of morphology, and moreover increases the electrical conductivity from insulating to semiconducting (conductivity of 3 ranges from 4.2 × 10−11 S cm−1 at 20 °C to 7.6 × 10−9 S cm−1 at 140 °C; activation energy = 0.59 eV; optical band gap = 0.6 eV). The structure and properties of the amorphous conductor are fully characterized by AC impedance spectroscopy, X-ray photoelectron spectroscopy, X-ray pair distribution function analysis, infrared spectroscopy, diffuse reflectance spectroscopy, electron spin resonance spectroscopy, elemental analysis, thermogravimetric analysis, and theoretical calculations
On-Chip Fuel Cell: Micro Direct Methanol Fuel Cell of an Air-Breathing, Membraneless, and Monolithic Design
Potential Magnetic Field around a Helical Flux Rope Current Structure in the Solar Corona
Fabrication and evaluation of micro-channel array for flexible on-chip PEMFC by new evaluation method and self-made hot embossing system
Size dependence of structural, magnetic, and electrical properties in corundum-type Ti 2
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