| Wide bandgap metal oxide semiconductors, such as TiO2, SnO2, Fe2O3, with good gas sensitivities, have achieved extensive research attention in recent years. Among them, Titanium oxide (TiO2) is the hot research point due to its advantages of low working temperature, high sensitivity and simple for fabrication. This work is mainly focus on the synthesis of the Array TiO2thin films and size-controllable nano-Ag particles, and assembles gas sensing devise to study the hydrogen sensing characteristics. The main research results are shown as follows:1ã€Array rutile TiO2thin films with the density and thickness controllable were successfully grown on FTO(F-doped SnO2) substrates using the hydrothermal method.2ã€A series of nano-Ag particles with uniform size-distribution were prepared using the reduction method and used in decorating the TiO2thin film. The sizes of the nano-Ag particles were controllable by adjusting NaOH concentration.3ã€The hydrogen sensing characteristics of TiO2modified by Ag nano-particles were systematically investigated. It was found that the sensitivity to the hydrogen was enhanced, from1.2to2.0at room temperature, and the response and the recovery time reduced, from40s and28s to31s and15s. The enhance of the sensitivity and the response time is caused by the band bending due to the contact between Ag and TiO2, which lead the electrons flows from TiO2to Ag particles, reduced the electron concentration at the TiO2surface, and thus accelerate the process of H adsorption and desorption.This study shows that Ag nano particle decorated at the TiO2surface help enhancing the sensitivity and respond time, and achieved hydrogen sensitivity at room temperature. It has potential application in the future gas sensing device. |
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