Chemoresistive NH3 gas sensor at room temperature based on the carbon gel-TiO2 nanocomposites

A resistive sensor based on films of carbon gel-TiO2 nanocomposites prepared with different percentages TiO2 by a sol-gel process, was developed to determine ammonia gas. thin film dispersed in poly(vinylidenfluoride) and deposited glass slides containing silver electrodes are used as NH3 sensor. The resistance the at potential difference 1.0 V determined presence NH3, CO2, C2H5OH, CH3OH, C4H10O C4H8O2 gases concentrations range 0–1000 ppm. response expressed sensitivity -Response (%)- increases linearly gas concentration from 0.2 18.8. is obtained room temperature, 25ºC, under UV irradiation. increase wt.% material. carbon-TiO2 nanocomposite 50 presents best performance terms (sensor ~18.8 for 100 ppm NH3), selectivity (selectivity factor about ~5.8 against C4H8O2, ~4.5 C2H5OH), stability (both long-term short-term) influence humidity. Additionally, this possesses advantages low power consumption, cost-effectiveness selective detection ability sensing.