Platinum Layer Research Articles

Direct Investigation of the Birefringent Optical Properties of Black Phosphorus with Picosecond Interferometry

AbstractBlack phosphorus (BP) is an emerging 2D semiconducting material with great potential for nanoelectronic and nanophotonic applications, especially owing to its unique anisotropic electrical and optical properties. Many theoretical studies have predicted the anisotropic optical properties of BP, but the direct experimental quantification remains challenging. The difficulties stem from the ease of BP's degradation when exposed to air in ambient conditions, and from the indirect nature of conventional approaches that are subject to large measurement uncertainties. This work reports a direct investigation of the birefringent optical constants of micrometer‐thick BP samples with picosecond (ps) interferometry, over the wavelength range from 780 to 890 nm. In this ps‐interferometry approach, an ultrathin (5 nm) platinum layer for launching acoustic waves naturally protects the BP flake from degradation. The birefringent optical constants of BP for light polarization along the two primary crystalline orientations, zigzag and armchair, are directly obtained via fitting the attenuated Brillouin scattering signals. A biexponential model is further proposed to analyze the Brillouin scattering signals for a random incident light polarization. The BP experimental results and the associated measurement sensitivity analysis demonstrate the reliability and accuracy of the ps‐interferometry approach for capturing the polarization‐dependent optical properties of birefringent materials.

Dye-sensitized solar cells using ionic liquids as redox mediator

In this research, the influence of ionic liquid on the conversion efficiency, incident photons to converted electrons (IPCE) and performance of fabricated solar cell was investigated using various ionic liquids. Ionic liquids with different substituents and ions were prepared and used as redox mediators in dye-sensitized solar cells (DSSCs). Ionic liquids were characterized 1H and 13C NMR spectra. We practically investigated the performance of ionic liquid salts were used as the mobile ions and found that the efficiencies of DSSCs were increased up to 40% comparing commercial electrolyte system. The ionic liquid compounds were incorporated in DSSCs to obtain an efficient charge transfer, solving the corrosion problem of platinum layer in counter electrode compared to commercial electrolyte.

Selective Hydrogenation of Acrolein to Propanal on a Pseudomorphic Pt/Ru(001) Bimetallic Surface

The selective hydrogenation of acrolein has been studied on different pseudomorphic Pt/Ru(001) bimetallic surfaces with platinum coverages of 0.28, 1.1, and 3.7 ML, using temperature-programmed reaction spectroscopy (TPRS), reflection absorption infrared spectroscopy (RAIRS), and Auger electron spectroscopy (AES). The submonolayer (0.28 ML) Pt/Ru(001) surface was found to be inactive towards acrolein hydrogenation and behaves mostly like a clean Ru(001) surface with the platinum layers enhancing the decarbonylation and decomposition pathways. The multilayer (3.7 ML) Pt/Ru(001) surface behaved like a Pt(111) surface with the acrolein mostly decomposing to CO and surface carbon with no observable hydrogenation activity. However, the 1 ML Pt/Ru(001) pseudomorphic surface was found to display properties different from those of Ru(001) and Pt(111) surfaces with the desorption of propanal, the only hydrogenation product, around 330 K, and propylene around 370 K. A submonolayer (0.67 ML) PtRu/Ru(001) alloy system prepared to study the effect of surface mixing (with small amounts of subsurface platinum) gave results similar to those of surface platinum at submonolayer coverages. This suggests that, at submonolayer coverages, there is little difference in the properties of these surfaces with respect to the location of the platinum atoms in the Pt/Ru(001) system.

New Insights in the Development of 3D Metal-Air Microbatteries

An increasingly number of studies is dedicated to the development of miniaturized sensors (“smartdust”), either for industrial purposes or for health monitoring. The requested power to get autonomous such miniaturized sensors led researchers to design efficient power sources. Microbatteries and microsupercapacitors have to be combined to fulfill such requirements. Our approach aims at miniaturizing metal-air batteries which can drastically boost the energy density available for smartdust sensors. In the frame of this study, the common thread is to design and to produce a full 3D microdevice in which energy is stored in the same way as in a metal-air battery. To address this task, the fabrication and characterization of miniaturized 3D metal anode and 3D macro-porous air cathode are proposed, each of those electrodes having a footprint area close to several mm2. First, a strategy for designing a 3D metal anode has been drawn, using CMOS compatible process. 3D zinc electrode (Zn micropillars) has already been electroplated through a porous membrane [1]. Despite an interesting technology, the 3D zinc scaffold is totally consumed after the first discharge (primary battery). The aim of our project is to produce a secondary metal-air microbattery by keeping safe the 3D template after the first discharge. A 3D metal electrode is then electroplated onto an inert 3D scaffold. To reach this goal, a 3D silicon template, consisting in an array of microtubes (Φ = 3 µm / depth = 50 µm) is fabricated. The lateral surface providing by the 3D scaffold allows the enhancement of the material mass loading while keeping constant the footprint area [2]. Once the geometry has been optimized by pushing back the limits of the silicon etching, the 3D scaffold is coated with a conformal deposit of metals. Zinc electroplated thin films has been deposited from an aqueous bath, and a similar approach for the electrodeposition of aluminum thin films was carried out from ionic liquids. Then, a micro-structured air cathode has been engineered using similar microelectronics processes. Air cathodes are composed of a conductive mesh, a catalyst and carbon material [3]. The project aims at reproducing the behavior of such air cathodes but at the millimeter scale: silicon wafer is double side etched with a tuned porosity. The top side of this topology acts as gas diffusion layer allowing the diffusion of oxygen into the miniaturized device. The bottom side of this electrode is composed of a large cavity, allowing the contact between the aqueous electrolyte, the catalytic sites and the oxygen. Conformal deposition of a platinum thin film is achieved by atomic layer deposition (ALD) to add the conductive contribution to the porous silicon scaffold. This platinum layer acts as the current collector and as the seed layer for catalysts electrodeposition process. These two electrodes have been separately characterized. Concerning the 3D metallic anode, various Zn-air prototypes have been assembled in KOH electrolyte using a homemade electrochemical cell with a commercially available air cathode. In the best configuration tested so far, this 3D Zn electrode can deliver a discharge capacity close to 1 mAh.cm-² with a flat discharge plateau at 1.2 V (fig. 1C). This value is three times higher than the one reported for state-of-art 3D Li-ion microbattery capacity using material thickness in the same order of magnitude [4]. Similarly, various Zn-air prototypes have been assembled using a Zn foil and the silicon micromachined air cathode in KOH electrolyte. A discharge plateau around 1.3V has been observed (fig. 1D). Finally, both components have been assembled to demonstrate the feasibility of a 3D metal-air primary microbattery with improved performance which will be reported in this communication. Acknowledgment: The RS2E and the DGA financially support this work. The French RENATECH network is greatly acknowledged for the microfabrication facilities.

INFLUENCE OF ELECTRIC FIELD ON ADHESION AND STRUCTURE OF CONDUCTING FILMS ON DIELECTRIC SUBSTANCES

Some results are provided confirming that modifying of the zinc films fabricated on glass substrates by a resulting effect of heat treatment in an atmosphere of dry air and action of cross electric field is possible. Using scanning electron microscopy (measured with the Zeiss Merlin microscope) the surface morphology of the films was studied. Also, the elemental composition of the films by micro-X-ray spectral analysis was studied. On the glass substrates, by the method of vacuum thermal evaporation, zinc films (Zn) with thickness of ~ 500 nm were obtained. In order to form ZnO films, the original films were treated at 250 °C in a dry air atmosphere, and in another case - in addition to the sample a transverse electric field with a potential of 300 V was applied. Platinum films on the silicon dioxide layer were obtained using the method of the ion-plasma sputtering. These layers were investigated by X-ray phase analysis, electron and atomic force microscopy. The thickness of platinum layers was 50 and 100 nm. During the deposition (deposition temperature – 300 °C, deposition rate - 5 nm / min), applied voltage between the platinum film and the silicon plate was 5 V. The films, obtained by applying a biasing, showed a more homogeneous fine-grained structure and a higher rate of growth than the original samples. In this way ZnO films can be manufactured with the extended surface. The possibility of significant changes caused by electric field use in adhesion, structure and conductive properties of the coatings is discussed. The method of depositing platinum on a dielectric substrate with an additional electrostatic field is also substantiated. It is shown that the application of an electric voltage to the film leads to a significant change in the structure of the resulting coating.Forcitation:Pshchelko N.S., Vodkailo E.G., Tomaev V.V., Klimenkov B.D., Koshevoi V.L., Belorus A.O. Influence of electric field on adhesion and structure of conducting films on dielectric substances. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 8. P. 100-104.

Growth and characterization of Pt-Si droplets for silicon nanowires synthesis

Abstract The formation of platinum silicide phases as a function of the annealing temperature was investigated using in-situ real-time Rutherford backscattering spectrometry. The in-situ real-time RBS revealed the reaction of platinum and silicon to start at about 220 °C to form platinum silicide phases, Pt2Si and PtSi in sequence. Scanning electron microscope revealed the morphological change in the platinum layer (formation of droplets) at 800 °C. The particle induced X-ray emission analysis showed the variation of platinum intensity, in the droplets areas, between 1600 and 2000 counts. The surrounding areas are left almost uncovered due to platinum film dewetting. In-plane as well as out-of-plane silicon nanowires were observed to form at 800 °C and 1000 °C using pulsed laser ablation and thermal annealing techniques, respectively.

Stabilising Oxide Core—Platinum Shell Catalysts for the Oxygen Reduction Reaction

Thin film planar models of core-shell catalysts for the oxygen reduction reaction in PEM fuel cells, have been synthesised with tin doped titania as the support for platinum. High-throughput methods have been used to investigate the effect that the level of tin doping in the titania core supporting material and the degree of crystallisation have on the loading of platinum at which bulk platinum like oxygen reduction behaviour is achieved. At high effective coverages of platinum, the oxygen reduction activity is always similar to that of a polycrystalline platinum electrode. This suggests that a continuous platinum thin film can always be formed at higher loadings. As the loading of platinum is decreased on all of the support materials studied, the activity eventually decreases, corresponding to effective platinum coverages that form nucleated particles on the support. The effective platinum coverage at which a continuous layer of platinum is formed, and exhibits the high activity, depends strongly on the support. The critical effective coverage, below which the oxygen reduction activity decreases, is ca. 5ML on anatase, and slightly higher on the amorphous phase of titania. Doping the titania with tin 10at.%>Sn>0% initially results in an increase in this critical effective coverage. At higher tin concentrations this critical coverage reduces again, and for supports with 23at.%<Sn<40at.%, only ca. 1.6ML is required. Therefore, these catalysts have the highest mass activity. Stability cycling of these catalysts also shows that they are the more stable supported systems. It is also shown that the doped titania support material itself is stable in a sulphuric acid environment at 80°C for Sn<at 28%. These results suggest that active and stable titania supported catalysts can be formed on tin doped supports with concentrations in the range 28at.%>Sn>23at.%.

Long term performance of porous platinum coated neural electrodes.

Over the last several years, there has been a growing interest in neural implants for the study and diagnostics of neurological disorders as well as for the symptomatic treatment of central nervous system related diseases. One of the major challenges is the trade-off between small electrode sizes for high selectivity between single neurons and large electrode-tissue interface areas for excellent stimulation and recording properties. This paper presents an approach of increasing the real surface area of the electrodes by creating a surface microstructure. Two major novelties let this work stand out from existing approaches which mainly make use of porous coatings such as platinum black or iridium oxide, or Poly(3,4-ethylenedioxythiophene) (PEDOT). Roughening is carried out by a dry etching process on the silicon electrode core before being coated by a sputtered platinum layer, eliminating complicated deposition processes as for the materials described above. The technology is compatible with any commonly used coating material. In addition, the surface roughening is compatible with high aspect ratio penetrating electrode arrays such as the well-established Utah electrode array, whose unique geometry presents a challenge in the surface modification of active electrode sites. The dry etching process is well characterized and yields a high controllability of pore size and depth. This paper confirms the superior electrochemical properties including impedance, charge injection capacity, and charge storage capacity of surface engineered electrode arrays compared to conventional arrays over a period of 12weeks. Furthermore, mechanical stability of the modified electrodes was tested by implantation in the brain of a recently deceased rat. In conclusion, the larger interface surface of the electrodes does not only decrease the impedance which should lead to enhanced Signal to noise ratio (SNR) for recording purposes, but also yields higher charge injection capacities, which improve the stimulation characteristics of the implants.

Schottky barrier diodes based on room temperature fabricated amorphous zinc tin oxide thin films

AbstractWe report on Schottky barrier diodes on the amorphous oxide semiconductor zinc tin oxide (ZTO). The ZTO thin films were grown by pulsed laser deposition at room temperature. Reactively sputtered gold, nickel, platinum, palladium, and silver layers were used to realize the Schottky contacts. To enhance rectification, a thin semi‐insulating zinc tin oxide layer was introduced at the metal–semiconductor interface. The forward current–voltage characteristics of the platinum Schottky barrier diodes were modeled using thermionic emission theory. From temperature dependent measurements, the mean barrier heights of the diodes were determined to be 0.8 and 1.3 eV for diodes without and with a semi‐insulating layer, respectively. Further, the Pt–ZTO diodes were investigated by capacitance–voltage measurements and thermal admittance spectroscopy (TAS). We found that the obtained net doping density agrees with the free electron density determined from Hall‐effect measurements. TAS revealed two defect levels: one deep defect with an activation energy of 220 meV and one shallow defect connected to the carrier freeze‐out. Assuming scattering at potential barriers within the conduction band minimum being the dominant scattering mechanism in multi‐cation semiconductors at freeze‐out temperature, an activation energy of about 15–27 meV was derived.

High-Performance Core–Shell Catalyst with Nitride Nanoparticles as a Core: Well-Defined Titanium Copper Nitride Coated with an Atomic Pt Layer for the Oxygen Reduction Reaction

A class of core–shell structured low-platinum catalysts with well-dispersed inexpensive titanium copper nitride nanoparticles as cores and atomic platinum layers as shells exhibiting high activity and stability for the oxygen reduction reaction is successfully developed. Using nitrided carbon nanotubes (NCNTs) as the support greatly improved the morphology and dispersion of the nitride nanoparticles, resulting in significant enhancement of the performance of the catalyst. The optimized catalyst, Ti0.9Cu0.1N@Pt/NCNTs, has a Pt mass activity 5 times higher than that of commercial Pt/C, comparable to that of core–shell catalysts with precious metal nanoparticles as the core, and much higher than that the latter if we take into account the mass activity of all platinum group metals. Furthermore, only a minimal loss of activity can be observed after 10000 potential cycles, demonstrating the catalyst’s high stability. Atomic-scale elemental mapping confirmed that the core–shell structure of the catalyst remaine...

Water splitting by CdS/Pt/WO3-CeOx photocatalysts with assisting of artificial blood perfluorodecalin

Photocatalytic hydrogen production from water splitting is an attractive scientific and technological route to address the increasing global demand for clean energy and to reduce the climate change impact of CO2 emission. Although tremendous efforts have been made, hydrogen generation from pure water by an efficient semiconductor catalyst driven by visible light still remains a significant challenge. Herein we present an effective photocatalyst based on Ce-doped WO3 and CdS powders embedded into platinum (Pt) layer. With the help of artificial blood component perfluorodecalin (PFDL), our system achieved 186.2μmol·g−1catalyst H2 in 4h without sacrifice reagent under visible light irradiation and maintained excellent stability in 24h without obvious decay. The hydrogen evolution activity and excellent stability are assigned to the enhancement of the electrons and holes relay and transfer by Pt layer, and the removal of nascent oxygen from catalyst via CeO2 and artificial blood PFDL path, and the suppression of undesirable hydrogen and oxygen recombination reverse reaction.

Acetylene-Treated Titania Nanotube Arrays (TNAs) as Support for Oxygen Reduction Reaction (ORR) Platinum Thin Film Catalysts

Platinum layers show higher specific oxygen reduction reaction (ORR) activities than nanoparticles, and smooth monolayers of platinum on polycrystalline gold have been achieved by electrodeposition from CO-saturated solutions. Since Pt monolayers are interesting catalytic systems, this methodology was attempted on acetylene-treated titania nanotubes (TNAs) with high conductivity. However, the investigation of the as-treated TNAs found that probably nanotubes with an oxygen-containing graphitic overlayer were formed. It was observed that deposition after partial oxidative removal of the overlayer led to very low ORR activities while deposition on the intact overlayer gave rise to the highest activities obtained in our research so far. This is attributed to a “tie-layer” effect, in which the carbon layer screens the negative effects of the underlying TiO2 layer. The interesting effects of the graphitic overlayer on the ORR activity of the Pt deposits on acetylene-treated TNAs offer a strategy to mitigate the unfavorable interactions of the Pt/TiO2 interface. However, the carbon layer in this study was found not to be stable upon potential cycling.

Flexible Non-Enzymatic Glucose Sensor Obtained Via Wet Metallization Coupled with Inkjet Printing

Flexible sensors and electronic devices constitute one of the great frontiers of research in the third millennium. The advantages of these technologies are obvious: the possibility to wrap or fold the devices (with space saving benefits), the opportunity to manufacture wearable accessories and the weight reduction of the final product [1]. Many vital sectors of the modern manufacturing industry are interested by the general evolution towards flexible electronics: displays, solar cells, batteries and sensors. In the case of biosensors in particular the development of flexible devices is particularly attractive due to their ability to adapt to human body, making possible the realization of wearable medical equipment. Example of biosensors include devices for the detection of glucose, organophosphates, proteins, antibiotics and many others. Their working principle may vary, but one of the most promising is the electrochemical one. Most of the electrochemical sensors are based on an enzyme mediated catalysis that produces or uses electrons. The resulting flux of current can be quantified and used for the sensing of the target specie. These sensors, called enzymatic, present however some disadvantages. Firstly, the enzyme loses activity over time. Moreover, the enzyme is typically not completely stable when immobilized on a substrate. For these reasons, a primary goal of modern research on biosensing is the development of non-enzymatic sensors. In the present work, a flexible non-enzymatic electrochemical glucose biosensor is presented. The functioning of the device is based on CuO, a common p-type semiconductor already used for the manufacturing of non-enzymatic glucose sensors [2, 3]. CuO nanoparticles are synthesized via a hydrothermal reaction and inkjet printed on a flexible substrate. Such flexible substrate is obtained by electroless plating with NiP a polymer sheet and by subsequently applying a platinum layer via electrolytic deposition. Sensitivity and selectivity of the obtained devices are finally tested with electrochemical techniques and their operative range is determined. The obtained single use bendable sensors may result of great interest for the control of patients affected by diabetes mellitus, a pathology that constitute one of the primary health risks in the world. [1] M. A. Alam, and S. Kumar; ed. B. Bhushan; “Flexible Electronics" chapter in Encyclopedia of Nanotechnology, Springer Netherlands, Dordrecht (2012) 860-865 [2] R. Ahmad, N. Tripathy, Y. B. Hahn, A. Umar, A. A. Ibrahim and S. H. Kim, Dalt. Trans. 44 (2015) 12488-12492 [3] R. Ahmad, M. Vaseem, N. Tripathy and Y. B. Hahn, Anal. Chem. 85 (2013) 10448-10454

Computer Analysis of the Field Ion Images of Platinum Irradiated with Ar+ (E = 30 keV) Ions

The work presents the field ion microscopy images of the surface atomic layers of irradiated platinum (layer-by-layer from 1st to 5th and more distant). A specially developed algorithm and software were used for image analysis to study the effect of Ar+ ions (E = 30 keV) on the subsurface atomic structure of pure platinum. The coordinates of atoms, the brightness of their images, and their sizes were determined. The curves of the distribution of the brightness and atomic radii were built. It is shown that the width of the distributions significantly decreases when moving from the damaged surface deep into the platinum bulk, whereas the number of atoms in the field ion microscopy images increases. Field ion microscopy images with only those atoms whose brightness (or radius) is in certain range were synthesized (these atoms can be highlighted in the ionic field microscopy images). It has been established that damaged zones include the images of atoms with both abnormally low and abnormally high radii. The principal possibility of reconstruction of the 3D-picture of the irradiated metal at a temperature of liquid nitrogen (T ∼ 77 K) is shown.

Development of photochromic device with magnetron sputtered titanium dioxide and tungsten trioxide films

A photochromic (PC) device comprising an electrochromic film (WO3) together with a photoactive film (usually, dye sensitized TiO2) coated on glass and a redox electrolyte (e.g., iodide/triiodide together with lithium salt) reduces the optical transmission under solar illumination and bleaches, again, in dark or at low intensity of light. This work reports, for first time, on an application of sputter coated TiO2 and WO3 films for this type of PC devices. The applicability of TiO2 and WO3 films in PC device is individually investigated in dye solar cells and electrochromic cells, respectively. A dye solar cell with 180nm TiO2 was shown to be sufficient for the charge generation for electrochromic coloration of the WO3. The compatibility of WO3 and redox electrolyte was studied in electrochromic devices by considering their redox potentials. The bleaching of the PC device has to be adjusted by the so called “loss current”. To address this, a thin catalytic layer of platinum (Pt) is deposited in between the photoactive and electrochromic layers. The optimized PC device exhibits a visual (solar) transmission modulation from 74 (63) down to 30% (20%) in 40min under 1.5 A.M. illumination, and the bleaching is regained in 45min in dark.

A pulsed laser synthesis of nanostructured bi-layer platinum-silver catalyst for methanol-tolerant oxygen reduction reaction

In the present work, we report the synthesis by pulsed laser deposition technique of binder-free platinum layer coated with silver layer, with each layer having a thickness of about 25 nm. The resulting Pt/Ag material exhibits clear electrocatalytic activity for oxygen reduction reaction (ORR) in alkaline solution. More interestingly, it shows no activity for methanol oxidation reaction (MOR), in contrast to Pt. Furthermore, the Pt/Ag catalyst demonstrates selective activity for ORR even in the presence of concentration of methanol as high as 5 M. Such high methanol tolerance indicates good perspectives for the application of Pt/Ag catalysts in alcohol fuel cell cathodes. For portable electronic applications, the binder-free structure of the Pt/Ag catalyst with its planar deposition make it very attractive as a cathode for membrane-type DMFCs or for membraneless fuel cells such as mixed reactant microfluidic fuel cell that depends on the characteristics of the electrodes to separate the oxidation and reduction reactions.

Molecule-specific interactions of diatomic adsorbates at metal-liquid interfaces.

Ultrafast vibrational dynamics of small molecules on platinum (Pt) layers in water are investigated using 2D attenuated total reflectance IR spectroscopy. Isotope combinations of carbon monoxide and cyanide are used to elucidate inter-adsorbate and substrate-adsorbate interactions. Despite observed cross-peaks in the CO spectra, we conclude that the molecules are not vibrationally coupled. Rather, strong substrate-adsorbate interactions evoke rapid (∼2 ps) vibrational relaxation from the adsorbate into the Pt layer, leading to thermal cross-peaks. In the case of CN, vibrational relaxation is significantly slower (∼10 ps) and dominated by adsorbate-solvent interactions, while the coupling to the substrate is negligible.

Inkjet-printed platinum counter electrodes for dye-sensitized solar cells

In this study, inkjet printing method was successfully demonstrated to produce catalytic platinum layers for dye-sensitized solar cells. Our work includes meticulous optical, morphological, and electrocatalytical analyses of precisely inkjet-patterned counter electrodes as well as traditionally drop-cast samples. Similar catalytic performance was obtained with both methods (RʹCT = 1.2 Ω cm2 for drop-cast and RʹCT = 1.6 Ω cm2 for inkjet-printed) at same Pt loading (ca. 2.5 μg/cm2), and correspondingly almost same cell efficiencies (ηdrop-cast = 6.5% and ηprinted = 6.7%). All the cells exhibited high stability by keeping their efficiencies after being subjected to a 1000 h aging test under 1 Sun and 35 °C at the open circuit condition. These results highlight the potential of inkjet printing to realize precisely patterned and no-material-wasting counter electrodes by controlled dispensing of the functional solution.

Improving the environmental performance of the internal combustion engine by the use of in-cylinder catalyst

The problems of using the inner surfaces of a combustion chamber as catalytic converters in order to reduce the harmful exhaust emissions were discussed in this paper. The proper choice of the catalyst is one of the most important issues. The interaction between the burned mixture and the catalyst is not limited by the kinetics of the chemical reactions but depends primarily on the flow rate of the reactants to the catalyst surface during combustion. The lifespan of a catalytic layer is determined by the application technique, where plasma spraying is the most popular and most accessible method. However, when it comes to the catalytic coating durability, it is not an efficient option, as ion implantation is indicated shows greater potential in this respect. In this research the coating of aluminum titanium and chromium-nickel have been applied to the engine head and the piston crown. Then the modified catalytic parts were used in a CI combustion engine and the obtained emission results were compared with the reference results. Another set of tests was performed for an SI engine, powered with gasoline and methane, where the piston crown was covered with a thermal layer of zirconium oxide and a catalytic layer of platinum. The beneficial effects of these in-cylinder catalysts on exhaust emissions and the possible problems in the wide spread use of such solutions have been presented.

SPR based fiber optic sensor with bi layers of indium tin oxide and platinum: A theoretical evaluation

Theoretical analysis of surface plasmon resonance (SPR) based fiber optic sensor with bi layers of ITO-Pt is carried out. Sensitivity and figure of merit (FOM) of sensor increase with increase in Pt layer thickness for all thicknesses of ITO layers. Though, for a fixed thickness of Pt layer, sensitivity and FOM are reduced with increase in ITO layer thickness. 50nm ITO–25nm Pt based SPR sensor reveals maximum sensitivity and FOM.