Sensing behaviors of transition metal decorated InN monolayer upon $$\hbox {SO}_{2}$$ SO 2 and NO molecules: a first-principles study

As revealed from the results of first-principles calculations, the indium nitride (InN) monolayer is capable of significantly facilitating its interaction with gas molecules after being modified with Transition Metals (TM). Accordingly, the adsorption behavior of Ag-doped InN (Ag–InN) and Pd-doped InN (Pd–InN) monolayers was investigated on two small gas molecules (i.e., $$\hbox {SO}_{2}$$ and NO). To make the proposed material more widely applicable, several critical parameters affecting the performance of gas sensors [e.g., adsorption distance, adsorption energy ( $$E_\mathrm{ad})$$ , charge transfer (QT), and density of state (DOS)] were analyzed in depth. As revealed from the results, both gases were capable of adsorbing stably on the surfaces of Ag–InN and Pd–InN monolayers. In addition, the analysis of electron localization function (ELF), DOS and spin band structure demonstrated the robust chemical interactions between Ag or Pd dopants and the activated atoms in the gas molecules. Given the theoretical results of the present study, we can gain insights into the sensing performance exhibited by the TM Ag as well as Pd modified InN surface. The mentioned prominent properties verified the feasibility of this material as a high-sensitivity gas sensor and could be effectively referenced for its application in sensing and catalytic fields.