A stable and highly sensitive room-temperature liquefied petroleum gas sensor based on nano-cubes/cuboids of zinc antimonate

Abstract

A new direction was explored using nanostructured zinc antimonate as a stable and highly sensitive LPG sensing material.

Synthesis of ZnAl2O4 and Evaluation of the Response in Propane Atmospheres of Pellets and Thick Films Manufactured with Powders of the Oxide

“…The response depicted in Figure 11 and Figure 12 is commonly observed in type-n semiconductor oxides [ 33 ] when they are exposed to atmospheres similar to ours [ 14 , 43 ]. Again, we consider that the increase in operating temperature (in our case from 200 to 300 °C) was a determining factor in the pellet’s response due to the presence of oxygen during the tests.…”

“…The response increase is associated with the increase in the concentration of the propane gas that reacts with chemisorbed oxygen (ionic oxygen) on the material’s surface due to the rise of temperature. That caused variations in the semiconductor’s electrical resistance (or conductivity) and the increase of the sensor’s response [ 5 , 14 , 15 , 36 ]. The trend shown in Figure 10 is consistent with the results of similar oxides reported in the literature [ 2 , 5 , 36 , 43 ].…”

“…In general, the response of a semiconductor material (such as the one studied in this work) is based on the mechanism that involves changes in the conductance (or electrical resistance) produced by the electron transfer that occurs during chemical adsorption [ 8 , 14 , 43 ]. Depending on the semiconductor type (p or n), the surface charge carriers may increase or decrease, as appropriate [ 14 ].…”

“…In general, the response of a semiconductor material (such as the one studied in this work) is based on the mechanism that involves changes in the conductance (or electrical resistance) produced by the electron transfer that occurs during chemical adsorption [ 8 , 14 , 43 ]. Depending on the semiconductor type (p or n), the surface charge carriers may increase or decrease, as appropriate [ 14 ]. The mobility and variations of the charge carriers depend on the temperature [ 49 ], the morphology, and the particle size of the semiconductor (which in our case was ~18.2 nm) [ 47 , 49 , 50 ].…”

“…Tin oxide (SnO 2 ) and zinc oxide (ZnO) nanoparticles are the most commonly used materials as gas sensors [ 12 ]. However, semiconductor oxides with more complex crystalline structures have also been suggested as alternative materials to be applied as gas detectors, like LaCoO 3 [ 13 ], ZnSb 2 O 6 [ 14 ], CoAl 2 O 4 [ 15 ], CoNb 2 O 6 [ 16 ], and more recently ZnAl 2 O 4 [ 17 ]. The high response shown by these semiconductors in atmospheres of CO, CO 2 , LPG, ethanol, and in humid environments is mainly due to the type of morphology, the high porosity and the nanometer size of the particles.…”