Scalable seeded growth of tungsten oxide nanowires for energy applications

Based on the vapor-solid mechanism, a seeded growth method was developed for the growth of tungsten oxide (WO3) nanowires. In this approach, beside the tungsten source heat at high temperature, additional tungsten seed particles were dispersed on the substrate to promote the growth of nanowires. The surface oxidation of the tungsten seed particles induced the local growth of nanowire seeds, which were further developed into dense and long nanowire arrays by the vapor transport from the tungsten source. Systematic study on the oxidization of tungsten particles was performed and optimal conditions for the seed formation were analyzed by the comprehensive consideration of growth parameters (e.g., growth temperature, particle size, and oxygen flow rate). The WO3 nanowires specimens were characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The seeded growth can enhance the growth of WO3 nanowires with controllable dimensions, providing a facile and scalable method for the growth of nanowires with large yield.