High Sensing Properties of 3 wt % Pd-Doped SmFe_1–xMg_xO₃ Nanocrystalline Powders to Acetone Vapor with Ultralow Concentrations under Light Illumination

Nanocrystalline powders of 3 wt % Pd-doped SmFe_1–xMg_xO₃ (x = 0, 0.1, 0.2, and 0.3) were prepared by a sol–gel method and annealed at 750 °C. Pd:SmFe_0.9Mg_0.1O₃ has a maximum response at 220 °C. When exposed to 0.5 ppm acetone vapor, the response of undoped SmFeO₃ is 2.26 and the response of Pd:SmFe_0.9Mg_0.1O₃ is 7.16. Under light illumination, Pd:SmFe_0.9Mg_0.1O₃ has a better sensing performance and lower optimal operating temperature. The sensor shows good selectivity and stability for acetone vapor. The high response and good selectivity of Pd:SmFe_0.9Mg_0.1O₃ to ultralow concentrations of acetone vapor indicate its potential for applications in many areas.