Effect of Al and Mg Doping on Reducing Gases Detection of ZnO Nanoparticles

Abstract

In this work, the main objective is to enhance the gas sensing capability through investigating the effect of Al and Mg doping on ZnO based sensors. ZnO, Mg1% doped ZnO, Al5% doped ZnO and (Al5%, Mg1%) co-doped ZnO nanoparticles (NPs) were synthesized by a modified sol-gel method. The structural characterization showed the hexagonal crystalline structure of the prepared samples. Morphological characterizations confirmed the nanometric sizes of the NPs (27–57 nm) and elemental composition investigation proved the existence of Al and Mg with low concentrations. The optical characterization showed the high absorbance of the synthesized samples in the UV range. The gas sensing performances of the synthesized samples, prepared in the form of thick films, were investigated. Sensing tests demonstrated the high influence of the Al and Mg on the sensing performances towards H2 and CO gas, respectively. The 5A1MZO-based sensor exhibits high sensitivity and low detection limits to H2 (<2 ppm) and CO (<1 ppm). It showed a response around 70 (at 250 °C) towards 2000 ppm H2 and 2 (at 250 °C) towards CO.

Development of a Conductometric Sensor Based on Al,Ca-Doped ZnO for the Detection of Formaldehyde

“…The sensing tests were carried out using a conductometric 3 × 6 mm ceramic platform with interdigitated contacts in Pt. Details on the conductometric ceramic platform have been reported in a previous paper [ 14 ]. Ten µL of nanomaterial dispersed in water was deposited on each device.…”

Ultrathin nanoporous metallic films and their integration in sensors

“…These films can serve as catalytic overlayers for gas sensors. Given the unique catalytic characteristics of different metals or their alloys, [24][25][26] varying the catalytic overlayer can enhance the gas selectivity of sensor devices.…”

Synthesis, Characterization, and Comparison of Pure Zinc Oxide and Magnesium‐Doped Zinc Oxide Nanoparticles and their Application on Ethanol Sensing Activities

“…The smaller crystallites provide much larger effective surface area to react with the gas and induce the positive effect on sensitivity. It was previously stated that the metal ion doping could tune the band gap by influencing the surface potential and increase the carrier concentration in the host material [38]. The inclusion of Mg into the ZnO structure enhances the sensing mechanism due to the lattice disorder hosted by the Mg 2+ ions, and large numbers of reactive oxygen molecules are adsorbed on the surface and available to interact with the reductive gases, and hence, the conductivity of the material gets increased [39].…”