Electrospun (La,Ba)FeO3 Nanofibers as Materials for Highly Sensitive VOC Gas Sensors.

In this work, we report the synthesis of perovskite-type Ba-doped LaFeO3 (La1-xBaxFeO3, x = 0.00, 0.02, 0.04, and 0.06) nanofibers (NFs) using the electrospinning method. The synthesized La1-xBaxFeO3 materials have a fibrous structure with an average fiber diameter of 250 nm. The fibers, in turn, consist of smaller crystalline particles of 20-50 nm in size. The sensor properties of La1-xBaxFeO3 nanofibers were studied when detecting 20 ppm CO, CH4, methanol, and acetone in dry air in the temperature range of 50-350 °C. Doping with barium leads to a significant increase in sensor response and a decrease in operating temperature when detecting volatile organic compounds (VOCs). The process of acetone oxidation on the surface of the most sensitive La0.98Ba0.02FeO3 material was studied using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature-programmed desorption in combination with mass spectrometry (TPD-MS). A mechanism for the sensor signal formation is proposed.