Glycothermal synthesis of assembled vanadium oxide nanostructures for gas sensing

This study demonstrates a facile but effective glycothermal method to synthesize vanadium oxide nanostructures for gas sensing detection. In this method, sodium orthovanadate was first dispersed and heated in ethylene glycol at 120-180 degrees C for a few hours, and then the precipitates were collected, rinsed, and sintered at high temperatures (e.g., 600 degrees C) for V2O5 in air and V2O3 in nitrogen, respectively. The as-prepared vanadium oxide particles are nanorods (200 nm x 1 mu m) and can assemble into microspheres or urchin-like structures with a diameter of similar to 3 mu m. The experimental parameters (temperature, time, and surfactants) and the formation mechanisms were investigated by various advanced techniques, such as transmission electron microscope, scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy, and thermo-gravimetric analysis. Finally, the V2O5 nanoparticles were tested for sensing detection of gas species of acetone, isopropanol, and ammonia. The microurchin structures show higher sensing performance than the nanorods.