WO3-LaFeO3 Nanocomposites for Highly Sensitive Detection of Acetone Vapor at Low Operating Temperatures

Abstract

The development of a rapid, highly sensitive, and dependable acetone sensor holds significant importance for human health and safety. To enhance the acetone sensing performance of LaFeO3 nanoparticles for practical applications, commercial n-type WO3 nanoparticles were incorporated as additives. They were directly mixed with LaFeO3 nanoparticles produced through a sol-gel method, creating a series of WO3-LFO nanocomposites with varying mass ratios. These nanocomposites were characterized using XRD, SEM, BET, and XPS techniques. Compared to pure LFO nanoparticles, the prepared nanocomposites exhibited larger specific surface areas with enhanced surface reactivity. The introduction of p-n heterojunctions through the mixing process improved the regulation of acetone molecules on internal carrier conduction within nanocomposites. As a result, the nanocomposites demonstrated superior acetone sensing performance in terms of optimal operating temperature, vapor response value, selectivity, and response/recovery speed. Notably, the nanocomposites with a 5wt% addition of WO3 showed the lowest optimal operating temperature (132 °C), the fastest response/recovery speed (28/9 s), and the highest selectivity against ethanol, methanol, and EG. On the other hand, the nanocomposites with a 10wt% addition of WO3 displayed the maximum vapor response value (55.1 to 100 ppm) at an optimal operating temperature of 138 °C, along with relatively good repeatability, stability, and selectivity.