Energy losses of electrons in carbon monoxide and carbon dioxide

Distinction of carbon monoxide (CO) gas from other combustible gases (especially from H 2 gas) is difficult using conventional SnO2-based ceramic sensors. Special methods, such as measurements under periodic temperature cycling between 100 and 300 °C, are required for CO gas sensing by SnO2based ceramic sensors [1]. A heterocontact of pand n-type semiconducting ceramics is one type of sensor using an interface [2-5]. For making heterocontacts, sintered ceramics of p-type and n-type semiconductors are physically contacted by pressing. In these sensors, the contact points are open to atmosphere gases due to the surface roughness, and the gas phases can react at the interface. This reaction changes the electrical properties of the interface, so that the devices can be used as gas sensors. In previous experiments, a CuO/ZnO sensor has shown excellent CO gas selectivity and a tunable sensing property by control of the applied bias voltages [5, 6]. The preparation of the ceramic contacts is simple, but these contacts do not provide the quantitative reproducibilities important for industrial gas sensors. To make stable p-n contacts, CuO/ZnO thin films were prepared by the sputtering method. This showed sensing properties for humidity and CO gas similar to those of the ceramic heterocontact, but CO gas sensitivity is not high due to the small open-interface area [7, 8]. In the present study, in order to increase the contact area and improve the reproducibility of the CO gas sensing properties, a ZnO-CuO composite was prepared by infiltration of aqueous solution of copper into porous ZnO, and firing. Microstructure and gas sensitivities for CO and H2 gases were examined for the CuO-infiltrated ZnO ceramics. Powder of ZnO (99.99% purity) was pressed into rectangular bars of 5 x 3 x 15 mm at 98 MPa, and sintered at 700 °C for 3 h. The relative density of the ZnO ceramics was 70-80% of the theoretical value. An aqueous solution of copper was obtained from 99.9% cupric nitrate (Cu(NO3)23H20; Kojundo Chemical). A part of the ZnO ceramics was dipped into 0.7 N cupric solution and fired at 600 °C for 1 h. The firing temperature was determined from the results of differential thermal analysis (DTA) which shows three endothermic peaks at 109 °C, 223 °C and 435 °C. Phases in the sample were confirmed

Impurity analyses of high-purity carbon monoxide gas using micro gas chromatography for development as a certified reference material

Sensing ability of carbon nitride (C6N8) for the detection of carbon monoxide (CO) and carbon dioxide (CO2)

Impregnated carbon based catalyst for protection against carbon monoxide gas

Restructured Beef Steaks Manufactured Using Carbon Dioxide, Oxygen and Carbon Monoxide Gas

Carbon implant has become one of the major co-implant steps in the fabrication of advanced semiconductor devices due to its proven effectiveness in controlling and reducing Transient Enhanced Diffusion (TED) in ultra-shallow junction formation. Carbon dioxide (CO 2 ) is still widely used as the feed gas for carbon implantation. However, it is well known that the high concentration of oxygen from CO 2 causes many problems, including oxidation of the implant arc chamber components, which leads to rapid performance degradation of the source. Phosphine (PH 3 ) is often used as a dilution gas to minimize the oxidation effect from CO 2 . However, its use usually results in a reduction of the C+ beam current, thereby negatively impacting the tool's productivity. In this paper, carbon monoxide (CO) is presented as an alternative carbon doping gas replacing CO 2 or CO 2 with PH 3 dilution (referred to as CO 2 /PH 3 throughout this paper). CO is shown to exhibit distinct performance improvements compared to CO 2 /PH 3 on the Applied Materials VIISta HCS high current implanter. Significant improvement in C+ beam current and source life with CO gas is noted.

Exploring the adsorption characteristics of toxic CO gas on pristine, defective, and transition metal-doped I-AsP monolayer

Flexible and cost effective CNT coated cotton fabric for CO gas sensing application

Theoretical study of the interactions of carbon monoxide with Rh-decorated (8,0) single-walled carbon nanotubes

Utilization of Fine coal gasified with CO2 (Carbon dioxide) gas to produce CO (Carbon Monoxide) fuel is one effort to utilize coal waste and utilize CO2 greenhouse gas emissions. Testing was carried out at the Sriwijaya University Laboratory in Palembang with the aim of analyzing the production process of CO gas as fuel by utilizing the greenhouse gas CO2 through the gasification of fine coal solid waste and knowing and analyzing the influence of temperature, reaction time and CO2 gas debid on the Boundouard reaction on gas yields. CO and CO2. So we get the variable that produces the expected CO gas. The initial stage is to prepare 2.3 kg of fine coal and the grain size has been filtered to a size of <3mm or or mesh 8 – 18 then heated to a temperature of 500˚C with a time of 68 minutes 48 seconds for the carbonization process. Fine coal that has been carbonized is then reacted with CO2 gas in a heating furnace at variable temperatures of 300 ˚C, 400 ˚C, 450 ˚C and 500˚C and at a flow rate of 2.5 L/min, 5 L/min, 7.5 L/min, 10 L/min, 15 L/min. From 26 test samples, it shows that the best variable for producing CO gas is heating at a temperature of 500˚C with a CO2 reactor gas discharge of 5 L/min which can produce CO gas with a concentration of 208,586 ppm and CO2 gas is 357,703 ppm with CO & CO2 ratio is 0.583.

A new diode-based carbon monoxide gas sensor utilizing Pt–SnO x/diamond

Summary form only given, as follows. Single-walled carbon nanotubes (SWNTs) are synthesized in a thermally non-equilibrium flow reactor, in which extreme molecular vibrational mode dis-equilibrium of the primary feedstock, carbon monoxide (CO) gas, is maintained by using a powerful and efficient CO gas laser. The CO molecules absorb the laser radiation on the lowest 10 vibrational transitions and transfer energy to high vibrational states by vibration-vibration energy exchange collisions. This leads to a highly non-equilibrium energy distribution in the CO, which provides enough energy for the carbon-producing CO disproportionation reaction to occur. The vibrationally excited CO reacts in the presence of metal catalysts to form, primarily, carbon dioxide and structured carbon molecules, notably SWNTs, in this continuous (non-batch) process. Iron pentacarbonyl is employed as the catalyst precursor, which dissociates in the plasma and subsequently forms small iron clusters. The influence of iron pentacarbonyl concentration on the quality of the nanotube material is investigated. Ropes of single-walled carbon nanotubes with a high degree of alignment have been observed in deposits created in the CO plasma without any post-production processing. A nanotube content of better than 50% is observed in the deposited material for certain synthesis conditions. At low pressure, substantial quantities of about 20 mg/hour of nanotube containing material are produced. The non-equilibrium synthesis process has been successfully scaled to high plasma pressures up to an atmosphere. We will present results on the production rate and purity of the nanotube containing material under these conditions. IR, visible and UV spectroscopy in the flow reactor has been used to control process parameters.

Development of CO gas conversion system using high CO tolerance biocatalyst

Highly sensitive MISFET sensors with porous Pt–SnO 2 gate electrode for CO gas sensing applications

In this paper, Carbon Monoxide (CO) gas sensor deposited on the Alumina substrate was fabricated by synthesizing a nanocomposite of Zinc Oxide (ZnO) and Graphene as a sensing layer via the hydrothermal method. ZnO-Gr nanocomposite was varied with ratio of 1:1, 1:3, and 1:5 to obtain the optimum composition in responding to CO gas. The sensing layer was exposed by CO gas to 5 concentration variations at room temperature and 1 concentration at 2 high temperature. Morphological structure of ZnO-Gr was presented through Scanning Electron Microscopy (SEM). It was found that ZnO-Gr nanocomposite with ratio of 1:3 at room temperature generated the highest % response to CO gas sensing. Decreased resistance occurs in step of increasing temperature. The property of semiconductor changes from p to n-type above $100^{\circ}C$; C temperature to CO gas exposure.