DFT Study on\nthe Janus ZrSSe Monolayer for Its Potential\nApplication in NO Gas Sensing

The growth of industry has resulted\nin increased global\nair pollution,\nnecessitating the urgent development of highly sensitive gas detectors.\nIn this work, the adsorption of the Janus ZrSSe monolayer for CO,\nCO<sub>2</sub>, NH<sub>3</sub>, NO, NO<sub>2</sub>, and O<sub>2</sub> was studied by first-principles calculations. First, the stability\nof the ZrSSe monolayer is confirmed through calculations of cohesive\nenergy and AIMD simulations. Furthermore, the calculations indicate\nthat the Se layer exhibits higher selectivity and sensitivity toward\ngas molecules compared to the S layer. Specifically, among the gases\nadsorbed on the Se layer, NO has the shortest adsorption distance\n(1.804 Å), the lowest adsorption energy (−0.424 eV), and\nthe greatest electron transfer (0.098 e). Additionally, density of\nstates analysis reveals that adsorption of NO, NO<sub>2</sub>, and\nO<sub>2</sub> on the Janus ZrSSe monolayer can induce a transition\nfrom a nonmagnetic to a magnetic state. The adsorption of NO not only\nalters the magnetic state but also induces a transition from a semiconductor\nto metal, which is highly advantageous for gas sensing applications.\nThere results suggest that the Janus ZrSSe monolayer has the potential\nto serve as a highly sensitive detector for NO gas.