Bare-Pt surfaces

The surface phonon dispersion of the bare Pt surface was determined by HATOF and is reported in Fig. 49 (open symbols). The RW (dots) and the L resonance (triangle) are observed. The RW presents... 

The detailed one-dimensional potential energy diagrams for propane dehydrogenation on both the flat and the stepped surfaces are given in Figs. 2.6 and 2.7. The sum of the total energies of the gas-phase propane and bare Pt surface is taken as the energy reference. 

In studies on Pt dotted silicon electrodes, PMC measurements revealed that tiny Pt dots increased the interfacial charge transfer compared with bare silicon surfaces in contact with aqueous electrolytes. However, during an aging effect, the thickness of the oxide layer between the silicon and the platinum dots gradually increased so that the kinetic advantage again decreased with time.11... 

Sandwich casting permits one to prepare an MIP film with uniform thickness [28, 106, 108, 109]. In this procedure, a drop of the solution containing a monomer, cross-linker, template and initiator is dispensed on the surface of a PZ transducer and covered with a microscope quartz slide. Then this assembly is exposed to UV light in order to initiate polymerization that results in a thin MIP film. The polymerization can be performed either on the activated immobilized initiator PZ transducer surface or on the bare transducer surface. For example, sialic acid has been determined with an MIP film immobilized on a platinum-film electrode of the quartz resonator using the former procedure [57]. That is, 1-butanethiol has been used for modification of the Pt surface. An indole-3-acetic acid plant hormone served as the template. An MIP-PZ chemosensor prepared that way operated reproducibly. That is, the coefficient of variation of the chemosensor performance was 9% for three different sensors. 

Fig. 37.11. Use of an NO microsensor for detection of the NO release from cultured endothelial cells. The sensor is a dual probe microsensor. The small sensor is a bare Pt UME used to position the sensor in the feedback mode. Onto the larger Pt electrode a polymer was deposited from an acrylic resin containing Ni(4-lV-tetramethyl) pyridyl porphyrin and served as amperometric NO sensor, (a) Schematic of the sensor, (b) optical microphotograph of the sensor surface, (c) Response of the NO sensor to the stimulation of the cells with bradykinin at different distances of the sensor to the surface of the cells. Reprinted with permission from Ref. [104], Copyright 2004, American Chemical Society.

Electroless deposition of Au in KAu(CN)2 -I- HF can be controlled by both the kinetic process and the diffusion process. The deposition is a two-step process, with initial diffusion-limited deposition of the intermediate species, followed by surface-limited reduction of this species. For electroless deposition of Pt, it has been reported that the rate-determining step is the deposition on n-Si, whereas it is the dissolution of silicon on p-Si. Electroless copper deposition does not occur on Si02-covered silicon surface due to the lack of anodic dissolution of silicon In a non-HF solution, the deposition of copper on a bare silicon surface results in the formation of oxide aroimd the metal particles. In HF solutions, the deposition of copper proceeds very slowly in the dark on both p-Si and n-Si samples due to the lack of carriers. The... 

Itaya and coworkers reported high resolution results for Cu deposited on Pt, Cu deposited on Pt, Ag deposited on Au,i77 17 Ag deposited on Pt, Hg deposited on Au. " This group simultaneously presented atomic resolution images for bare electrodes surfaces, e.g., Pt, Rh, Ni. aiid Co ... 

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