Enhanced triethylamine sensing characteristics of In-doped WO3 cubic nanoblocks at low operating temperature

Abstract

This study accomplished the one-pot hydrothermal synthesis of cubic WO3 nanocubes both in their pure form and doped with In (3 wt%, 5 wt%, and 7 wt%). The morphological and microstructural features of these cubic nanoblocks were assessed using various techniques including XRD, SEM, TEM, XPS, and BET analysis. Gas sensing tests were conducted on pure and In-doped WO3 cubic nanoblocks, using triethylamine (TEA) as the test gas. Among all tested samples, the 5% In-WO3 sensor showed the highest response to 50 ppm TEA (Ra/Rg = 11.2). The gas sensor additionally demonstrates rapid responses and recovery times, long-term stability, and outstanding selectivity, all of which are crucial for the construction of effective TEA gas sensors. The improvement of gas sensing performance may be due to the increase of oxygen vacancies and surface adsorbed oxygen after In-doping and the large specific surface area.