A ZnO/ZnFe₂O₄ n–n heterojunction and Au loading synergistically improve the sensing performance of acetone

Abstract

In this work, Au nanoparticle-loaded ZnO/ZnFe2O4 (Au-ZnO/ZnFe2O4) microspheres were prepared using a combination of a two-step hydrothermal process and co-precipitation method. The SEM and TEM analyses showed that the synthesized...

Expanding Selectivity Functionality of a ZnO Nanotetrapod-Based Volatile Organic Compound Sensor Using Au Nanoparticle Decoration

“…The mechanism behind the VOC-induced resistance modification of an n-type semiconductor material has been attributed to the adsorption and reactions of gas molecules occurring on the surface of the semiconductor materials. ,, When the sensor is placed in air, oxygen molecules are adsorbed on the surface of the sensor. They capture electrons from the conduction band of ZnO and increase its electrical resistance.…”

“…Resistance-based gas sensors are becoming one of the most widely used sensors because they are sensitive and portable and can be easily minimized. − Temperature considerably affects the performance of semiconductor-based gas sensors. Increasing the temperature increases the amount of energy available for crossing the activation barrier for initiating the response reaction, changing the adsorbed oxygen species, , transferring the adsorption types, , and increasing the reaction rate and gas desorption …”

“…3−11 Temperature considerably affects the performance of semiconductor-based gas sensors. Increasing the temperature increases the amount of energy available for crossing the activation barrier for initiating the response reaction, 12 changing the adsorbed oxygen species, 13,14 transferring the adsorption types, 13,15 and increasing the reaction rate and gas desorption. 15 Semiconductor-based gas sensors exhibit poor gas selectivity owing to their relatively open sensing mechanism.…”

“…29 Compared to ZnFe 2 O 4 and ZnO/ZnFe 2 O 4 , Au-ZnO/ZnFe 2 O 4 exhibits a higher response and decreased response and recovery times in detecting acetone, and the optimum working temperature decreased from 279 to 206 °C. 14 Au NP modification of SnO 2 can effectively increase the response to triethylamine vapor and decrease the working temperature of SnO 2 , and the activation energy was calculated and demonstrated a decreased activation energy induced by Au species. 30 Similar analysis was performed on Pt-decorated WO 3 used for detecting triethylamine 31 and encapsulated metal NPs for catalysis.…”

“…The optimum working temperature of a ZnO-based sensor decreases from 325 to 300 °C and a dramatically enhanced response to 100 ppm ethanol is observed after AgAu alloy decoration . Compared to ZnFe 2 O 4 and ZnO/ZnFe 2 O 4 , Au-ZnO/ZnFe 2 O 4 exhibits a higher response and decreased response and recovery times in detecting acetone, and the optimum working temperature decreased from 279 to 206 °C . Au NP modification of SnO 2 can effectively increase the response to triethylamine vapor and decrease the working temperature of SnO 2 , and the activation energy was calculated and demonstrated a decreased activation energy induced by Au species .…”