Study of WO3/Pt hydrogen sensitive film fabricated by Sol-Gel method

Pt-doped WO3 materials have good hydrogen-sensing properties, which are widely used in the field of hydrogen sensing. In this paper, Sol-Gel method is used to prepare WO3/Pt sensing ma-terial and sensing characteristic to hydrogen is characterized by transmission optical fiber hydrogen sensing system fabricated at home. By optimizing the fabrication parameters including sol-gel viscosity, aging time, Pt:W moral ratio and layers of the sensing film, the sensitivity and repeatability of the film were greatly improved. The repeatability of the film is further improved by irradiating the film with an UV lamp. Experimental results show that by increasing the number of film layers from one to five (the thickness of the film is about 222 nm, and the content of Pt element is 13.47% by SEM test), the sensitivity increased by 1.666 times. The repeatability of the film can be improved by 3% through the irradiation of the ultraviolet lamp. The optimized WO3/ Pt film was tested continuously for 12 times at 5% hydrogen concentration, and the zero drift was only 0.723%.