Tungsten Oxide Urchin-Flowers and Nanobundles: Effect of Synthesis Conditions and Heat Treatment on Assembly and Gas-Sensing Characteristics

摘要

The synthesis and assembly of tungsten oxide nanowires into building blocks are important for nanodevices, such as electrochromic, bio, and gas sensors. In this study, tungsten oxide nanowires with different assembly morphologies of nanobundles and urchin-flowers are synthesized by the wet chemical solvothermal method. The assembly, crystal structure, and specific surface area of the synthesized materials are characterized byus-ing field-emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and nitrogen adsorption/desorption isotherm. The effects of the assembly on the ammonia gas-sensing characteristics of tungsten oxide nanowires are systematically investigated from 350 ℃ to 450 ℃. Results show that the assembly morphologies of the tungsten oxide nanowires markedly influence the gas-sensing performance of devices. The relationships of gas-sensing characteristics with the diameter, porous structure, and specific surface area of the synthesized materials are also discussed.