Enhanced selective acetone sensing characteristics based on Co-doped WO3 hierarchical flower-like nanostructures assembled with nanoplates

Co-doped WO3 hierarchical flower-like nanostructures assembled with nanoplates (FNPs) were synthesized by a one-step hydrothermal route. The as-synthesized FNPs were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). The gas sensing properties of the pure and Co-doped WO3 FNPs were tested to various volatile organic compounds (VOCs). Among pure and Co-doped WO3 FNPs, 0.6 at% Co-doped WO3 presented the best properties. It was found that 0.6 at% Co-doped WO3 FNPs exhibited quite short response and recover time of about 2 s and 10 s in response to 100 ppm acetone gas. And the response of 0.6 at% Co-doped WO3 FNPs to 100 ppm acetone gas was 103, which was about 5 times higher than pure WO3. The improvement of gas sensing properties could be attributed to the morphology changes of Co-doped WO3 FNPs as well as the defect of WO3 lattice and Co catalysis effect to promote gas adsorption.