Hydrogen Gas Sensing Properties of AgNPs-Doped Titania Nanotubes by Electroless Deposition

Titania nanotubes thin films have been prepared by electrochemical anodization of Ti foil at room temperature (~25C), in ethylene glycol base electrolyte with 0.5wt. % NH4F and 4wt % deionized water at 30V at time 3hr and then AgNPs-doped TiO2 nanotube arrays at different deposition ratios (0.3, 0.5, 0.7, 0.9 wt %) were carried out by electroless deposition. These tubes are well aligned and organized into high-density uniform arrays. The average tube diameter, ranging in size from 61 to 74 nm, the length of the tube 2.13, and ranging in size of wall thickness from 21 to 29 nm. A possible growth mechanism is presented. The TiO2 nanotubes were characterized by X-ray diffraction (XRD), scanning electron microscope (FESEM) and energy dispersive X-ray spectroscopy (EDX. ( Gas sensors based on AgNPs/TiO2 nanotube arrays thin films were fabricated, and their sensing properties were investigated. The AgNPs/TiO2 nanotube sensor demonstrated a good sensitivity at different concentration hydrogen atmospheres ranging from (15, 30, 45, 60, 75ppm) H2. A temperature-dependent sensing from 25C to 300C was also found with an applied voltage was constant at 6V.