Impact of TiO2/Graphene-Oxide coated on quartz crystal resonator on the sensing performance of NH3, N2 and ethanol at room temperature

Abstract

Gas sensors based on Quartz Crystal Resonator device coated with TiO2/Graphene-Oxide (GO) films were fabricated to sense ethanol, ammonia, and nitrogen at room temperature. TiO2 nanostructures, as gas sensing film, were fabricated by drop casting TiCl4 aqueous solution with different concentrations, and analyzed by SEM, TEM, XRD and profilometer. Exposed to the above mentioned gases, the responses of the sensors, Δf, were measured. Sensor with 55 nm TiO2 film shows higher response to N2 and 100 ppm concentration of ethanol and NH3 than the others, due to larger surface area of the film, which are 635, 334, and 528 Hz, respectively. To improve the response further, TiO2/GO film is prepared, the response of which for N2 and 100 ppm concentration of ethanol and NH3 increased significantly to 848, -360 and 740 Hz, respectively. Sensing mechanisms are based on changing in mass and elasticity properties of the device. High response, simple and low cost preparation and room temperature operation are the main advantages of these sensors making them attractive for future applications.