Surface Acoustic Wave Hydrogen Gas Research Articles

Spectral studies of phthalocyanines

The paper presents the results of research of the optical properties of nickel-phthalocyanines (NiPc) in a wide spectrum range of optical radiation . Phthalocyanines belong to the group of organic semiconductors with a complicated molecular structure. Spectral characteristics of complex refractive index and optical transmission coefficient were determined. The tests were carried out in the range of wavelengths of optical radiation: 300-2500 nm. By means of Surface Plasmon Resonance (SPR) method, tests concerning the possibilities of using nickel phthalocyanines in gaseous sensors of nitrogen dioxide in atmospheres of air and nitrogen were carried out. Full Text: PDF ReferencesP. Górka, St. Kowalski, Investigation of air pollution, Ed. by SUT, Gliwice, Poland, 2000 CrossRef J. Ignac-Nowicka, T, Pustelny, Z. Opilski,E. Maciak,W. Jakubik, M. Urbanczyk, "Examination of thin films of phthalocyanineas in plasmon system for their application in NO2 sensors", Optical Engineering, 42 (10), 2978 (2003) CrossRef T. Pustelny J. Ignac-Nowicka, Z. Opilski, "Optical investigations on layered metalphthalocyanine nanostructures affected by NO2 applying the surface plasmon resonance method", Opt. Appl. 34(4), 563 (2004) DirectLink J. Homola, "Surface Plasmon Resonance Sensors for Detection of Chemical and Biological Species", Chemical Reviews, 108(2), 462 (2008) CrossRef E. Maciak, T. Pustelny, "An optical ammonia (NH3) gas sensing by means of Pd/CuPc interferometric nanostructures based on white light interferometry", Sensor and Actuators, B: Chemical 189, 230 (2013). CrossRef N.B. McKeown, "Phthalocyanine-containing polymers", Journal of Materials Chemistry, 10 (9), 1979 (2000) CrossRef T Pustelny, J. Ignac-Nowicka, B. Jarzabek, A. Burian, "Optical investigations concerning layered metalphthalocyanine nanostructures affected by NO2", Opt. Appl. 34(4), 551 (2004) DirectLink A. Rydosz, E. Maciak,K. Wincza,S. Gruszczynski, "Microwave-based sensors with phthalocyanine films for acetone, ethanol and methanol detection", Sensors and Actuators, B: Chemical. 237, 876 (2016) CrossRef T. Pustelny, J. Ignac-Nowicka, Z. Opilski, "Experimental investigation of thin metalphthalocyanine layers CuPc, PbPc, NiPc by plasmon resonance method to be applied in NO2-sensors", Opt. Appl. 34(2), 249 (2004) DirectLink W. Jakubik, M. Urbanczyk, E. Maciak, T. , "Surface acoustic wave hydrogen gas sensor based on layered structure of palladium/metal-free phthalocyanine", Bull. Pol. Acad. Sci.-Tech. Sci., 56(2), 133 (2008) DirectLink M. Piliaric, J. Homola, "SPR Sensor Instrumentation", Chemical Sensors and Biosensors, 4, 95 (2006) CrossRef

Development of a Pd/Cu nanowires coated SAW hydrogen gas sensor with fast response and recovery

Employing palladium and copper nanowires (Pd/Cu NWs) as the sensitive interface, a new surface acoustic wave (SAW) sensor with fast response and recovery was developed successfully for hydrogen gas sensing. The adsorption in Pd/Cu NWs towards hydrogen molecules modulates the SAW propagation by the induced acoustoelectric coupling effect from the changes in the resistivity of Pd, and the corresponding shifts in oscillation frequency proportional to gas concentration was collected as the sensor signal. Larger surface-to-volume of the Pd/Cu NWs contributes to improve the response speed and sensitivity. A 150 MHz SAW device with delay line pattern was fabricated photolithographically on 128° YX LiNbO3 substrate, and the Pd/Cu NWs that synthesized by optimized electrochemical deposition were dissolved in ethanol and deposited onto the SAW device surface by dropping method to build the SAW hydrogen sensors. The prepared SAW sensors were characterized by using the differential oscillation loop experimentally, excellent repeatability, fast response and recovery within 4s, and a sensitivity of 1.5 kHz/%were achieved at room temperature (25°C). Additionally, the response mechanism in hydrogen sensing was investigated experimentally.

A polyaniline/WO 3 nanofiber composite-based ZnO/64° YX LiNbO 3 SAW hydrogen gas sensor

Polyaniline/WO 3 nanofiber composite-based surface acoustic wave (SAW) gas sensor has been investigated towards hydrogen (H 2). Chemical oxidative polymerization of aniline was employed to synthesize polyaniline nanofibers with WO 3 nanoparticles. The nanocomposite was deposited onto a layered ZnO/64 ° YX LiNbO 3 SAW transducer. The sensor was exposed to various concentrations of H 2 gas and operated at room temperature. The sensor response was found to be 7 kHz towards 1% of H 2 in synthetic air. A fast response and recovery with good repeatability in a stable baseline condition were observed at room temperature.

A ZnO nanorod based layered ZnO/64° YX LiNbO 3 SAW hydrogen gas sensor

A zinc oxide (ZnO) nanorod based surface acoustic wave (SAW) sensor has been developed and investigated towards hydrogen (H 2) gas. The ZnO nanorods were deposited onto a layered ZnO/64° YX LiNbO 3 substrate using a liquid solution method. Micro-characterization results revealed that the diameters of ZnO nanorods are around 100 and 40 nm on LiNbO 3 and Au (metallization for electrodes), respectively. The sensor was exposed to different concentrations of H 2 in synthetic air at operating temperatures between 200 °C and 300 °C. The study showed that the sensor responded with highest frequency shift at 265 °C. At this temperature, stable baseline and fast response and recovery were observed.