Facile synthesis and gas sensing properties of La2O3–WO3 nanofibers

A series of La2O3-doped WO3 nanofibers were synthesized by an electrospinning method in this work. The structure composition and morphology of nanofibers were characterized by XRD (X-ray diffraction), field emission scanning electron microscopy (FESEM), selected area electron diffractive (SAED), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). Sensors based on these nanofibers were fabricated by hot-press on the ceramic plates. The gas sensing properties of the undoped and La2O3-doped WO3 (La3+:W6+ =1 mol%, 3 mol% and 5 mol%) nanofibers were tested to various gases. The sensors based on La2O3-doped WO3 nanofibers, in which the molar ratio of La3+:W6+ is 3:100, exhibit highest response toward 100 ppm acetone, having a response about 12.7, which is almost 2 times higher than that of sensor based on pure WO3 nanofibers. These results indicate that the acetone sensors based on the La2O3-doped WO3 nanofibers exhibit fast response and good repeatability characteristics, which are promising for acetone sensors which used by air-quality and environmental monitoring.