Flower-like tungsten oxide particles: Synthesis, characterization and dimethyl methylphosphonate sensing properties

Flower-like WO3 particles with high specific surface area were synthesized via a template/surfactant-free way. Scanning and transmission microscopies and X-ray diffraction were applied to investigate the formation mechanism of the morphology. Gas sensing characterization showed an enhanced sensitivity (70 Hz/ppm) to dimethyl methylphosphonate (DMMP) as compared with previously reported WO3 nanoflakes (38 Hz/ppm) at a DMMP concentration of 4 ppm. Cross-sensitivity results revealed that flower-like WO3 still showed sound sensitivity in presence of interfering agents, which benefited from its intrinsic high sensitivity. The mechanism of DMMP adsorption on the flower-like WO3 particle was studied by in situ diffuse reflectance infrared Fourier transform spectroscopy.