Enhancement in the Selectivity and Sensitivity of Ni and Pd Functionalized MoS<sub>2</sub> Toxic Gas Sensors
Levna Chacko, Ettore Massera, P. M. Aneesh
Abstract
Atmospheric pollution is one of the major aspects of concern which led to the research of sensors for the detection of toxic gases. The supreme surface-to-volume ratio makes two-dimensional MoS 2 a promising material to be used as an electronic sensor. Here, we demonstrate the fabrication of a high-performance gas sensor based on atomic-layered MoS 2 nanoflakes synthesized by a facile hydrothermal process. Structural and morphological studies confirmed the formation of few-layered phase pure hexagonal MoS 2 nanoflakes. The results demonstrate that the Pd-MoS 2 layers exhibited a very high relative response to NO gas (700%) at 2 ppm concentration with a minimum NO detection limit of 0.1 ppm and Ni-MoS 2 demonstrated a relative response of 80% towards H 2 S gas with a limit of detection of 0.3 ppm with good repeatability and selectivity, owing to the increased adsorption energy of NO on Pd-MoS 2 and H 2 S on Ni-MoS 2 through the formation of PdNO x and NiS 2 complexes respectively. The improved sensing performance of this MoS 2 -based sensor also suggests the great potential and possibility of MoS 2 related 2D materials and its combinations for the development of futuristic highly sensitive nanosized gas sensors suitable for anti-pollution automotive system and as volatile biomarkers.