ppb-Level Detection Triethylamine Gas Sensor Based on Ag-Doped Nanosheets-Assembled Octahedron Zn₂SnO₄

Abstract

The current semiconductor sensors cannot detect the ultralow concentration of triethylamine (TEA). Therefore, this article uses the catalytic activation effect of precious metal silver and combined with the unique physical and chemical properties of ternary metal oxides to design the Ag-doped Zn2SnO4 gas sensor to detect the ultralow concentration of TEA. In this work, spinel-type metal oxide Zn2SnO4 was prepared by a one-step hydrothermal method and its functional modification by means of precious metal doping. The countenance and elemental content of the synthesized products were dissected through diverse means. Combined with the characterization data, it is shown that Zn2SnO4 samples all present a fixed octahedral shape and the surface is assembled by a large number of nanoplates. The gas sensing test results show that the gas sensor based on 3 at% (atom percent) Ag-doped Zn2SnO4 has the best gas sensing performance for TEA. Its response to 100-ppm TEA at 250 °C is 273.33. At the same time, the minimum detectable concentration level is 100 ppb. In addition, the material also demonstrates fast response time, good stability, and high selectivity. The excellent gas sensing performance is mainly attributed to the synergistic effect of chemical sensitization and electron sensitization of precious metal silver.