UV activated single aligned TiO2 nanofiber embedded silver nanoparticles as room temperature ammonia gas sensor

Abstract

In this work, by using an electro-spinning process and a secondary electrostatic field on rectangular electrodes, a single-aligned nanofiber of silver nanoparticle (SNP)-TiO2 fabricated for NH3 gas sensing with UV irradiation at room temperature. XRD, FE-SEM and UV spectroscopy adopted for characterization of the single nanofiber. The response of SNP-TiO2 single nanofiber sensor evaluated for 70 ppb to 12 ppm ammonia gas at room temperature up to the optimum temperature of 150 °C. The response of this sensor for 5 ppm ammonia gas is 46.1 at the optimum temperature of 150 °C. However, the response is also evaluated at room temperature under 365 nm UV illumination. The response improved up to 4 times from 11 at dark condition to 45.1 under UV illumination for the ammonia gas concentration of 5 ppm. In addition, UV light exposure led to a considerable reduction in both the response and recovery times. Moreover, the results for detecting other gases such as methanol, ethanol, propanol and water vapor compare to ammonia shows that for SNP-TiO2 sensor the best response is for ammonia gas, whereas its sensitivity to humidity is considerably low (about 9%). This shows the sensor can be used in related applications like breath analysis.