NO2 Gas Sensing Properties of Ag-Functionalized Porous ZnO Sheets

Herein, we report a simple and scalable synthesis route to prepare Ag-functionalized porous ZnO sheets and their enhanced NO2 gas sensing properties. Porous ZnO sheets functionalized with well-dispersed submicron Ag particles were prepared by using a hydrothermal method-based one-pot synthesis route from Zn and Ag precursors. NO2 gas sensing performance (response, selectivity, response time, and recovery time) was optimized at 200 degrees C in the gas sensor fabricated with 3 at% Ag-functionalized porous ZnO sheets. We demonstrated a response (R-g/R-a) of 17.18 to 10 ppm NO2 gas and also obtained a high response of 14.05 even at 60% relative humidity due to the synergetic effect of improved NO2 gas adsorption in the presence of Ag particles and increased resistance by the formation of Schottky barrier at Ag-ZnO heterojunctions.

Automated summary

In this study, a simple and scalable synthesis route was developed to prepare Ag-functionalized porous ZnO sheets, which exhibited enhanced NO2 gas sensing properties. The porous ZnO sheets were functionalized with well-dispersed submicron Ag particles using a hydrothermal method-based one-pot synthesis route. The gas sensor fabricated with 3 at% Ag-functionalized porous ZnO sheets showed optimized NO2 gas sensing performance at 200 degrees C, with a high response of 17.18 to 10 ppm NO2 gas and a response of 14.05 even at 60% relative humidity, attributed to the synergistic effect of improved NO2 gas adsorption and increased resistance at Ag-ZnO heterojunctions.