Chromium and Ruthenium-Doped Zinc Oxide Thin Films for Propane Sensing Applications

Abstract

Chromium and ruthenium-doped zinc oxide (ZnO:Cr) and (ZnO:Ru) thin solid films were deposited on soda-lime glass substrates by the sol-gel dip-coating method. A 0.6 M solution of zinc acetate dihydrate dissolved in 2-methoxyethanol and monoethanolamine was used as basic solution. Chromium (III) acetylacetonate and Ruthenium (III) trichloride were used as doping sources. The Ru incorporation and its distribution profile into the films were proved by the SIMS technique. The morphology and structure of the films were studied by SEM microscopy and X-ray diffraction measurements, respectively. The SEM images show porous surfaces covered by small grains with different grain size, depending on the doping element, and the immersions number into the doping solutions. The sensing properties of ZnO:Cr and ZnO:Ru films in a propane (C3H8) atmosphere, as a function of the immersions number in the doping solution, have been studied in the present work. The highest sensitivity values were obtained for films doped from five immersions, 5.8 and 900, for ZnO:Cr and ZnO:Ru films, respectively. In order to evidence the catalytic effect of the chromium (Cr) and ruthenium (Ru), the sensing characteristics of undoped ZnO films are reported as well.

Gas Sensing Properties of NiSb2O6 Micro- and Nanoparticles in Propane and Carbon Monoxide Atmospheres

“…For example, SnO 2 showed in [11] maximum responses of ∼0.4 and ∼0.6 at concentrations of 100 and 500 ppm of propane at 300 ∘ C, respectively. In our case, the highest response was of ∼1.125 at a C 3 H 8 concentration of 500 ppm and of ∼2.14 at a CO concentration of 300 ppm, both at 300 ∘ C. In addition, we have previously reported [14,15,25,27] that the trirutile-type Journal of Nanomaterials …”

“…The pellets' electrical resistance was measured at C 3 H 8 and CO concentrations of 0, 5, 50, 100, 200, 300, 400, and 500 ppm, at temperatures of 23 (ambient), 100, 200, and 300 ∘ C. Their gas response ( ) was calculated by the relative difference of the electric conductance (the reciprocal of the electric resistance), according to the expression [5,[11][12][13][14] …”

“…ZnO and SnO 2 are the most commonly used oxides to detect C 3 H 8 and CO because they possess good thermal stability in these gases [11,12]. The semiconductor oxides LaCoO 3 and CoSb 2 O 6 are currently investigated as detectors of C 3 H 8 and CO, showing good stability and a high response at moderate temperatures (between 250 and 350 ∘ C) [13,14].…”

Facile Synthesis, Microstructure, and Gas Sensing Properties of NdCoO3 Nanoparticles

“…A sensitivity of ∼17 (CO) and ∼31 (propane) was reached for LaFeO 3 nanoparticles at 350 ∘ C and a gas concentration of 200 and 300 ppm, respectively [43]. On the other hand, undoped SnO 2 and ZnO thin films showed sensitivities of 0.7 and 2.5, respectively, at 300 ∘ C and a propane concentration of 300 ppm [44,45]. The good response of the NdCoO 3 toward gases can be attributed to the microstructure obtained during the synthesis process.…”

Sensing and Sensor Fundamentals

“…Pollution monitoring, for example CO, NO • 2 , SO 2 , and O 3 (Nihal, et al, 2008, Wetchakun, et al, 2011 Breath analyzers, for breath-alcohol content (BAC) measurements (Knott, 2010) • Domestic gas monitoring, such as propane (Gómez-Pozos, et al, 2013) • Temperature, as in integrated electronic equipment (Fraden, 2010) • Magnetism, for example, magnetometers for six degrees of freedom applications • (Coey, 2010, Sze, et al, 2007 Optical sensing, such as in charge-coupled device detectors in cameras ( • EUROPE.COM, 2013)…”