Ultra-high sensitivity and selectivity of Au nanoparticles modified MoO3 nanobelts towards 1-butylamine

Abstract This study demonstrates an ultra-sensitive material towards 1-butylamine. The material is composed of 4 wt% Au nanoparticles decorated on MoO3 nanobelts, which are prepared via the hydrothermal method and in-situ reduction. The related characterizations reveal that the nanobelts are highly crystallized layer structures with a width of ~ 200 nm, a thickness of 40 nm and a length of several micrometers. The Au/MoO3 composites exhibit ultra-high sensing response (~300) towards 100 ppm of 1-butylamine at the working temperature of 240 °C. Even without Au decoration, the pristine MoO3 nanobelts offer the response as high as ~ 90 toward the same concentration of 1-butylamine at the temperature of 340 °C, much higher than the existing materials. More importantly, the proposal materials have excellent selectivity towards 1-butylamine, which offers the possibility for practical use. The excellent sensing performance is attributed to the unique sensing mechanism of the layered MoO3 nanobelts via catalytic reaction between 1-butylamine and the lattice oxygen of MoO3. Besides, Au decoration enables to enhance the adsorption of 1-butylamine and facilitate the catalytic sensing process, resulting in further increase in sensing response and selectivity of 1-butylamine. This study may shield light on a promising high-performance gas sensing materials to detect amines in practical application.