Surface reaction mechanism and characteristics of 2-dimensional TiO2 and 0-dimensional Ag nanocomposites specialized for H2S gas sensing at room temperature

• Synthetic approach to fabricate the Ag NPs-decorated TiO 2 NSs is provided. • Ag NPs-decorated TiO 2 NSs gas sensor exhibits better performance towards H 2 S gas. • The uniform decoration of Ag NPs on TiO 2 NSs significantly enhances the H 2 S gas sensing properties due to the catalytic effect of Ag and accelerated electron transfer through the formation of Ag/TiO 2 heterojunctions. In this study, we provide the synthesis of pristine TiO 2 nanosheets (NSs) via a simple flux method and their decoration with Ag nanoparticles (NPs) using a hydrothermal method for room-temperature H 2 S gas sensing. Gas sensing experiments were conducted at 25 °C, evaluating the response of the Ag NPs-decorated TiO 2 NSs to various gases. Results demonstrated the gas sensor exhibited a superior response to H 2 S gas compared to other gases, outperforming the pristine TiO 2 NSs gas sensor. Additionally, its response to H 2 S gas surpassed that of the TiO 2 NSs gas sensor, highlighting the promising role of Ag decoration for H 2 S gas detection. Sensing behavior in humid atmosphere was also investigated. The improved H 2 S gas sensing performance can be attributed to the catalytic effect of Ag, the formation of Ag/TiO 2 heterojunctions, and the large surface area of the TiO 2 NSs. This study introduces a straightforward approach to enhance the gas sensing capabilities of metal oxide NSs.