UV Illumination Room-Temperature ZnO Nanoparticle Ethanol Gas Sensors

Abstract

Zinc oxide (ZnO) nanoparticle gas sensor was formed by spin coating. We annealed the film at 400, 600, and 800• C for 1 hour in air to make gas sensor. The responses of gas sensor to ethanol with UV light illumination were investigated. It could be observed that the ZnO nanoparticle film annealing at 800• C has the highest sensitivity. It can be attributed to the defects of ZnO nanoparticle film annealing at 800• C much more than other annealing temperatures. The study shows that the ZnO nanoparticles have potential applications as RT ethanol sensors.

Room-temperature photodetectors and VOC sensors based on graphene oxide–ZnO nano-heterojunctions

“…Indeed, with the pristine zinc oxide only relatively high concentrations (8 ppm) of ethanol (as representative analyte) can be detected at RT, showing a fairly low signal intensity as displayed in Figure S4. This may be attributed to the relatively large size of the ZnO grains (77 nm) with respect to the high-performing ones (d p smaller than 40 nm), reported in the literature 20,33 . Indeed, to the increasing of nanoparticle size corresponds a reduction of the grain boundary density, thus resulting in a resistance to the electron conduction 33 .…”

“…The solution was stirred for 4 h. Then, 100 mL of MilliQ water was introduced dropwise, keeping the suspension in the ice bath due to the highly exothermic reaction. The mixture was stirred for other 2 h at 70 -80 °C and, finally, 200 mL of MilliQ water (at 60 °C) followed by 20 dilution of %wt H 2 O 2 by Sigma-Aldrich) were slowly added. The brownish slurry was left to decant overnight at room temperature.…”

“…However, these devices have usually the disadvantage of high operating temperature, which in turn adversely affects their long-term stability. Nevertheless, the latter drawbacks can be moderated, for example, by co-synthesizing metal oxides with other oxides/non-metal elements 19,20 or by doping them with metal nanoparticles (such as Pt or Ag) 21 . Besides, another method recently explored is the coupling of the metal oxides with graphene-based materials 1,22 .…”

Breakthroughs in the Design of Novel Carbon-Based Metal Oxides Nanocomposites for VOCs Gas Sensing

“…Moreover, the poor selectivity [36,37], scarce life-time and usually high operating temperatures [25,38] represent the major shortcomings of this type of detection. Thus, aimed at overcoming the above-mentioned drawbacks, the co-synthesis of metal oxides with other oxides/non-metal elements [39,40], their doping with metal nanoparticles (such as Pt or Ag) [24] and/or their coupling with carbon-based materials [26,41] can be valid alternatives.…”

Design and Optimization of an Al Doped ZnO in Si-Slot for Gas Sensing

“…The doping concentration and the structural morphology of such oxides determine the sensitivity and selectivity of all these sensors. In a nano-sized sensor with its larger surface-to-volume ratio, the interaction with the sensing object is larger compared to the bulk sensors, leading to increased sensitivity and reduced operating temperature [9]- [11].…”