Superior triethylamine sensing enabled by Pr-doped MoO₃ flake-stacked nanostructure

This study employed a one-step hydrothermal method to prepare pure MoS₂ samples and Pr-doped MoS₂ materials. MoO₃ and Pr-doped MoO₃-based Triethylamine gas sensors were fabricated through calcination. The elemental composition and morphology of the materials were investigated using characterization techniques including XPS, XRD, and SEM. Effective substitution of Pr³ ⁺ ions for Mo⁶⁺ lattice sites was achieved, yielding layered stacked rectangular prism nanomaterials composed of rectangular sheets of varying dimensions. At its optimal operating temperature of 250 °C, the sensor exhibited high response, rapid recovery, excellent selectivity, repeatability, long-term stability, and moisture resistance. The significantly enhanced response to Triethylamine is attributed to Pr doping, which promotes surface oxygen adsorption and increases oxygen vacancy concentration. This modification intensifies electron capture, widens the electron depletion layer, and facilitates a greater release of trapped electrons upon gas exposure. Consequently, the surface potential barrier is sharply reduced, leading to a pronounced macroscopic resistance transition. A detailed mechanistic analysis of this sensing behavior is provided.