In this study, matchhead WOx-capped ZnO nanorods (NRs) were formed by hydrothermal and sputtering processes. In order to examine the morphology and material properties, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction were performed. Amorphous circular-shaped WOx heads were successfully grown on top of ZnO NRs. In order to explore the optical and gas responses of the nanostructures, UV-light responses and H2 gas responses were measured for pure ZnO NRs and WOx/ZnO NRs. The results indicate that the WOx matchhead cap can function like an umbrella to block the light absorption and gas reaction. Furthermore, the light and gas response times were lengthened due to the coverage of the WOx match head. WOx matchhead/ZnO nanocomposites can function as light and gas modulation components for optoelectronic devices.
In this study, the effects of magnesium (Mg) doping and Ammonia (NH3) plasma on the pH sensing capabilities of InGaZnO membranes were investigated. Undoped InGaZnO and Mg-doped pH sensing membranes with NH3 plasma were examined with multiple material analyses including X-ray diffraction, X-ray photoelectron spectroscopy, secondary ion mass spectroscopy and transmission electron microscope, and pH sensing behaviors of the membrane in electrolyte-insulator-semiconductors. Results indicate that Mg doping and NH3 plasma treatment could superpositionally enhance crystallization in fine nanostructures, and strengthen chemical bindings. Results indicate these material improvements increased pH sensing capability significantly. Plasma-treated Mg-doped InGaZnO pH sensing membranes show promise for future pH sensing biosensors.
In this study, ZnO, AlZnO, Al2O3, and Al2O3-doped ZnO-sensing membranes were fabricated in electrolyte–insulator–semiconductor (EIS) structures. Multiple material analyses indicate that annealing at an appropriate temperature of 500 °C could enhance crystallizations, passivate defects, and facilitate grainizations. Owing to their material properties, both the pH-sensing capability and overall reliability were optimized for these four types of membranes. The results also revealed that higher Al amounts increased the surface roughness values and enhanced larger crystals and grains. Higher Al compositions resulted in higher sensitivity, linearity, and stability in the membrane.
Hydrogen is an energy source for a fuel cell power generation system. It can be continuously produced if sustainable and renewable fuels (such as alcohols, vegetable oils, and used cooking oils) are used. Thermal plasma hydrogen reformer (H 2 -Reformer), which has fuel-flexible and high volume production capabilities, is a critical key component for production of hydrogen as energy use. We have developed such a 1-kWe H 2 -Reformer that effectively reforms different types of renewable energy sources and water. Technically it is basically a steam reforming of hydrocarbons using thermal plasma. No catalysts are used in the reformation. The reformation is very effective for heavy hydrocarbon fuels.In the paper, an integrated unit of 1-kWe fuel processing system was constructed. The theoretical data are calculated based on thermal equilibrium calculations. The experimental conditions were also based on the optimal conditions for producing total SOFC fuel from thermal equilibrium calculations. Experimental tests were performed in a temperature range from 400 C o to 750 C o using ethanol as energy source. The experimental test data have good fit with the theoretical data. An optimal design was achieved by combining ECU for system controls, available software tool for optimal operational conditions at different operational parameters, and analytical laboratory capability for quality control of reformate stream.
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