Year: 2025
Type: article
Abstract: Hydrogen sulfide (H 2 S) sensing at room temperature with reliable and sensitive detection methods remains as major concern owing to its toxicity and wide range of applications. Herein, we propose a novel approach of Bougainvillea (green) extract mediated thin film synthesis for sensing of H 2 S at ambient operating temperature (~ 80 ± 2 °C). The structural, morphological, and sensing properties of the thin films were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy (AFM), and gas sensing measurements. The XRD analysis revealed the crystalline nature of SnO 2 thin films, with a predominant tetragonal rutile phase (grain size ~ 15 nm and film thickness ~ 1.32 μm). TEM and AFM observations confirmed the uniform and dense morphology of the films with surface roughness of ~ 14.8 nm suitable for gas sensing applications. XPS revealed the presence of flavonoid-derived functional groups (C–O, O–C = O), originating from the extract, which facilitated selective H₂S adsorption via sulfur–hydroxyl interactions. These bio-derived groups contributed to enhanced surface reactivity and gas sensing performance. The sensor exhibited excellent sensitivity at ~ 5 ppm with a good response and recovery time (22s/18s), and was highly selective (~ 82.41%) among other VOCs. The sensing mechanism can be attributed to the catalytic effect of Bougainvillea extract, which facilitated the adsorption and desorption of H 2 S molecules on the SnO 2 surface. Overall, the Bougainvillea extract-mediated SnO 2 thin films offer a promising platform for lower operating temperature sensing of H 2 S, with potential applications in environmental monitoring, industrial safety, and healthcare sectors. Further optimization and integration with electronic devices could potentially enhance their practical utility in real-world scenarios.
Source: Discover Materials
Authors: N. Bhuvaneshwari, Ashwath Narayana, R. Sundaraguru
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,590
OpenAlex ID: W7101437147