Effect of carrier gas on the gas sensing performance of Co12xNixMnxFe2yCeyO4 double-substitution spinel in flammable gases and volatile organic compounds

The presence of high concentrations of flammable gases and volatile organic compounds in the atmosphere has been widely reported to be detrimental to human survival. A lot of research effort has been put toward finding an efficient means of quick detection of these gases below their ‘immediately dangerous to life or health’ concentrations. Detecting these gases in an oxygendeficient environment is a crucial task to consider and has been overlooked. In this research, doublesubstitution spinel with the chemical formula Co12xNixMnxFe2yCeyO4, where 0 x = y 0.3, was prepared via the glycol-thermal technique. The final products, following appropriate substitution, were CoFe2O4 (dried naturally), CoFe2O4 (dried with infrared lamp), Co0.8Ni0.1Mn0.1Fe1.9Ce0.1O4, Co0.6Ni0.2Mn0.2Fe1.8Ce0.2O4 and Co0.4Ni0.3Mn0.3Fe1.7Ce0.3O4 spinel ferrites. The X-ray diffractometry (XRD), high-resolution transmission electron micrographs (HRTEM) and X-ray photoelectron spectroscopy (XPS) of the samples confirmed the formation of the spinel. The gas sensing performance of these samples was tested at the operating temperature of 225 C toward liquefied petroleum gas (LPG), ammonia, ethanol and propanol. The Co0.8Ni0.1Mn0.1Fe1.9Ce0.1O4-based sensor was selective to LPG, with a high response of 116.43 toward 6000 ppm of LPG when helium was used as the carrier gas, 3.35 when dry air was the carrier gas, 4.4 when nitrogen was the carrier gas, but it was not sensitive when argon was used as the carrier gas.https://www.mdpi.com/journal/coatingsam2024PhysicsNon

Tungsten oxide thin film for room temperature nitrogen dioxide gas sensing

Tungsten oxide (WO3) thin films for gas sensing have been successfully deposited using reactive direct current (DC) magnetron sputtering at different deposition temperatures (300 °C, 400 °C and 500 °C). The structural, morphological properties, thickness and composition have been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Rutherford backscattering spectrometry (RBS) techniques. To investigate the effect of deposition temperature on the gas sensing properties of deposited thin films on alumina substrates, was conducted using the Kenosistec gas sensing unit. WO3 thin film deposited at 500 °C exhibited a higher response when sensing Nitrogen dioxide (NO2) at room temperature as compared to the thin films prepared at 300 °C and 400 °C, respectively. However, as deposited WO3 thin films exhibited low sensitivity when sensing reducing gases such as hydrogen (H2) and ammonia (NH3), which was an indication of good selectivity properties of WO3 related sensors

Tungsten oxide thin film for room temperature nitrogen dioxide gas sensing

Tungsten oxide (WO3) thin films for gas sensing have been successfully deposited using reactive direct current (DC) magnetron sputtering at different deposition temperatures (300 °C, 400 °C and 500 °C). The structural, morphological properties, thickness and composition have been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Rutherford backscattering spectrometry (RBS) techniques. To investigate the effect of deposition temperature on the gas sensing properties of deposited thin films on alumina substrates, was conducted using the Kenosistec gas sensing unit. WO3 thin film deposited at 500 °C exhibited a higher response when sensing Nitrogen dioxide (NO2) at room temperature as compared to the thin films prepared at 300 °C and 400 °C, respectively. However, as deposited WO3 thin films exhibited low sensitivity when sensing reducing gases such as hydrogen (H2) and ammonia (NH3), which was an indication of good selectivity properties of WO3 related sensors