Strain-modulated adsorption of gas molecule on graphene: First-principles calculations

Graphene is an attractive material for applications in gas sensing because of its high surface-to-volume ratio and superior carrier mobility. Manipulating the adsorption as well as desorption behaviors of gas molecules on nanomaterials via strain has been found to improve their sensing performance. Utilizing first-principles calculations, this study investigated the effect of compressive and tensile strains on the adsorption properties of NH3 and NO2 molecules on graphene. The calculations demonstrated the applied strain and the adsorption energy were linearly related. In addition, the strain response of NO2 was significantly larger than that of NH3. In particular, the adsorption energy of NO2 increased by approximately 70 % under a compressive strain of 10 %, whereas NH3 exhibited minimal variations in its adsorption energy and charge transfer with graphene under strain. These findings highlighted the promising prospect of graphene as a continuously tunable sensing material for detecting small gases by applying strain. Therefore, strain-modulated graphene can serve as a highly sensitive gas sensing material and provide new insights into designing advanced graphene gas sensors with tunable properties.