▎ 摘　　要

Armchair (A) and zigzag (Z) type graphene nanoribbons (GNR) have been investigated for its suitability to sense the toxic H2S gas, by using density functional theory (DFT) based ab-initio approach. On adsorption of H2S, the variations in original metallic behaviour of ZGNR and semiconducting behaviour of AGNR has further been analysed by observing the conductance and bandgap variation as a function of H2S distance from GNR surface. The HOMO-LUMO profiles have also been analysed to understand the chemistry of GNRs and H2S molecule. Further, the current-voltage characteristics in presence of H2S near the nanoribbon surface, also shows the sensing of H2S, discussed in terms of that the current in both the nanoribbons increases due to H2S presence. The computed sensitivity confirms the zigzag GNR as better sensor than its armchair counterpart however, relatively with less recovery time than its zigzag counterpart.