The sensitivity enhancement of TiO₂-based VOCs sensor decorated by gold at room temperature

Abstract

Detection of hazardous toxic gases for air pollution monitoring and medical diagnosis has attracted the attention of researchers in order to realize sufficiently sensitive gas sensors. In this paper, we fabricated and characterized a Titanium dioxide (TiO2)-based gas sensor enhanced using the gold nanoparticles. Thermal oxidation and sputter deposition methods were used to synthesize fabricated gas sensor. X-ray diffraction analysis was used to determine the anatase structure of TiO2 samples. It was found that the presence of gold nanoparticles on the surface of TiO2 enhances the sensitivity response of gas sensors by up to about 40 %. The fabricated gas sensor showed a sensitivity of 1.1, 1.07 and 1.03 to 50 ppm of acetone, methanol and ethanol vapors at room temperature, respectively. Additionally, the gold nanoparticles reduce 50 seconds of response time (about 50% reduction) in the presence of 50 ppm ethanol vapor; and we demonstrated that the recovery time of the gold decorated TiO2 sensor is less than 40 seconds. Moreover, we explain that the improved performance depends on the adsorption-desorption mechanism, and the chemical sensitization and electronic sensitization of gold nanoparticles. Detection of hazardous toxic gases for air pollution monitoring and medical diagnosis has attracted the attention of researchers in order to realize sufficiently sensitive gas sensors. In this paper, we fabricated and characterized a Titanium dioxide (TiO2)-based gas sensor enhanced using the gold nanoparticles. X-ray diffraction analysis was used to determine the anatase structure of TiO2 samples. It was found that the presence of gold nanoparticles on the surface of TiO2 enhances the sensitivity response of gas sensors by up to about 40 %. The fabricated gas sensor showed a sensitivity of 1.1, 1.07 and 1.03 to 50 ppm of acetone, methanol and ethanol vapors at room temperature, respectively. Additionally, the gold nanoparticles reduce 50 seconds of response time (about 50% reduction) in the presence of 50 ppm ethanol vapor; and we demonstrated that the recovery time of the gold decorated TiO2 sensor is less than 40 seconds. Moreover, we explain that the improved performance depends on the adsorption-desorption mechanism, and the chemical sensitization and electronic sensitization of gold nanoparticles.

Enhanced sensing performance of armchair stanene nanoribbons for lung cancer early detection using an electric field

“…9 In recent years, many theoretical and experimental investigations have been carried out to synthesize and develop lung cancer detection sensors. 7,10,11 A variety of materials have been explored as gas sensors such as metal oxides, [12][13][14] carbon nanotubes, 15 and two-dimensional (2D) materials. 16,17 The 2D materials exhibit unique characteristics including sensing properties that have not been observed before.…”

Graphene and metal–organic framework hybrids for high-performance sensors for lung cancer biomarker detection supported by machine learning augmentation

“…18 Notably, these metal oxide-based materials typically operate in the temperature range of 125–250 °C, leading to compromised selectivity and reduced stability due to the heightened reactivity of metal oxides with interfering gases at elevated temperatures. Some other methodologies were found to boost VOC sensors that can work at room temperature by decorating metal oxides with gold nanoparticles, 19 or using conductive polymers ( e.g. iodine-doped polyvinyl acetate); 20 however, the drawbacks are that the sensitivity reduces and the response time takes longer.…”

Room Temperature Chemiresistive Gas Sensors Based on 2D MXenes

“…However, with an increase in the sensing temperature, more gas molecules can be adsorbed on the surface of the sensor, leading to enhanced gas response. It should be noted that some metal oxides are able to work at RT [3]. However, some metal oxides have a very high resistance, in the range of Giga ohms, at RT, and some of them show too much noise and drift at RT, making difficult to measure their electrical properties.…”