Gas sensing properties of graphene oxide loaded with SrTiO3 nanoparticles

This paper reports a straightforward and inexpensive method for the fabrication of gas sensing devices based on graphene oxide (GO) synthesized by a modified Hummer's method and decorated with strontium titanate perovskite (SrTiO3). The active layers developed were employed for the detection of hazardous gases such as NO2, CO2, and NH3. The physical and chemical properties were also analyzed using various experimental techniques including field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and Raman spectroscopy. Repeated response and recovery cycles were applied in the detection of nitrogen dioxide (NO2), carbon dioxide (CO2), and ammonia (NH3). Accordingly, the gas sensing study reveals that decorated GO exhibits a high response towards NO2 at an operating temperature of 100 degrees C with good sensitivity (up to 4-fold higher than that of pristine GO) and highly improved selectivity. Additionally, the effect of ambient humidity was tested for NO2, demonstrating that GO/SrTiO3 sensors show a good immunity to humidity cross-sensitivity. Lastly, a gas sensing mechanism was schematically proposed and discussed. These findings prove that the func-tionalization of GO with SrTiO3 can overcome the limitations of GO-based sensors by enhancing their ad-sorption capability of gas molecules and their sensitivity towards target gases. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This paper presents a simple and low-cost method for fabricating gas sensing devices using graphene oxide (GO) decorated with strontium titanate perovskite (SrTiO3). The active layers developed were capable of detecting hazardous gases such as NO2, CO2, and NH3 with high sensitivity and selectivity. The physical and chemical properties of the materials were analyzed using various experimental techniques, and a gas sensing mechanism was proposed and discussed. These findings demonstrate that functionalizing GO with SrTiO3 can enhance the adsorption capability and sensitivity of GO-based gas sensors.