ppb-Level detection of isopropanol based on porous ZnSnO3/Ag through the synergistic effects of Ag and amorphous nanocube structures

Abstract

Noble metal-doping has proven to be an effective method for improving the gas sensing performances of most reported semiconductor sensors. Herein, porous Ag-doped ZnSnO₃ nanocubes were synthesised using a simple co-precipitation and deposition method followed by calcination. The detection of ppb-level isopropanol was easily achieved by adjusting the doping amount of Ag. Various analytical techniques were utilized to assess and characterize the sample's morphology, composition, and structure. The resulting ZnSnO₃/Ag-3 sensor showed an outstanding response value (120) for 100 ppm isopropanol at 250 °C, which was enhanced 6.95 times compared to that of pure ZnSnO₃ nanocubes. The sensor also boasted a remarkable limit of detection (LOD) of 10 ppb as well as excellent repeatability and long-term stability. This work discusses the enhanced gas sensing mechanism of the ZnSnO₃/Ag sensor, which involves the unique porous nanocube structure of the sample and the excellent electronic and chemical sensitization enabled by Ag. The results suggest that Ag-doped porous ZnSnO₃ nanocubes hold great promise for isopropanol gas sensing applications.