Abstract
A low-temperature H(2)S gas sensor was designed using 3% Fe-doped SnO(2)/rGO nanocomposite as the sensing material. Fe-doped SnO(2) quantum dots (QDs) were prepared using a sol-gel combustion method, subsequently leading to the formation of the Fe-SnO(2)/rGO nanocomposite through a simple sonication process. To evaluate the performance of the sensor material, the sample underwent comprehensive characterization using XRD, FE-SEM, HRTEM, Raman shift, XPS and BET surface area analysis based on nitrogen (N(2)) adsorption-desorption. The XRD pattern HR-TEM confirmed the formation of a well-defined tetragonal crystal phase of SnO(2), indicating high structural integrity. Meanwhile, the BET analysis revealed a specific surface area of 72.7 m(2) g(-1) with pore size of 7.83 nm. Morphological analysis (HR-TEM) revealed that 3% Fe-doped SnO(2) QDs was uniformly dispersed on the rGO surface, with an average particle size of 5.6 nm. Gas sensing performance of pristine SnO(2) (S1), 3% Fe-doped SnO(2) QDs (S2), and 3% Fe-SnO(2)/rGO (S3) nanocomposite based sensors was evaluated at operating temperatures ranging from 25 °C to 175 °C. Incorporation of rGO significantly enhanced the sensitivity of the 3% Fe-doped SnO(2)/rGO nanocomposite towards H(2)S compared to pristine SnO(2) and 3% Fe-SnO(2) QDs. The 3% Fe-SnO(2)/rGO (S3) based sensor demonstrated a significant response of about 42.4 to 10 ppm H(2)S at a low operating temperature of 100 °C, with a rapid response time of 21 seconds. It also exhibited excellent selectivity for H(2)S against interfering gases such as NH(3), LPG, and CO. The enhanced sensitivity and selectivity are attributed to the synergistic interaction between 3% Fe-SnO(2) and rGO. A possible gas sensing mechanism underlying the improved performance of the nanocomposite is discussed.