Research On Controllable Surface Adsorption Of WO₃ Quasi-one-dimensional Nanostructures

WO3 nanowires have unique crystal structure、physical and chemical properties, which makes it become one of the most important functional components for the construction of nano electronic device. The surface of WO3 nanowires can absorb different gases, resulting in the fluctuation of its electrical conductivity. The electrical conductivity of WO3 nanowires change when it absorb different type of gases. Therefore WO3 nanowires has a function of selecting gas and can be applied to gas sensing materials. In this thesis we mainly realize controllable gas absorption properties on the surface of WO3 nanowires by annealing it under different hydrogen atmosphere. Experimental results are listed as follows:1. We successfully Controllable synthesized WO3 nanowires by taking hydrothermal method. The WO3 nanowires were characterized by X ray diffraction and scanning electron microscopy. The synthesized WO3 nanowires are standard hexagonal phase, with diameters of 100-200 nm and lengths up to 10 micrometers.2. The optoelectronic device based on individual tungsten trioxide nanowire was fabricated by conventional photolithography procedure and metal stripping technology. Water molecules adsorption characteristics were investigated by testing the transport properties of WO3 nanowires under different relative humidity.3. We take the method of annealing under hydrogen atmosphere to realize the controllable gas absorption properties on the surface of WO3 nanowires. We also research the photoelectric properties of the WO3 nano device at the same time.The experimental results show that the response of WO3 nanowires to relative humidity can be improved by annealing under hydrogen atmosphere. Hence we can build Sensors based on on individual tungsten trioxide nanowire. Which have high sensing properties、low energy consumption、micro dimension.