Tuning the Gas Sensing Properties of ZrS2 Monolayers via Pt Modification: Insights from DFT Simulations

This study investigates the gas sensing properties of Pt–modified ZrS₂ monolayers for seven harmful environmental gases (CO, H₂S, NH₃, NO, NO₂, SO₂, and SO₃) using density functional theory (DFT). The adsorption structures, charge transfer, band structures, density of states, sensitivity, and recovery times are systematically analyzed. The results reveal that Pt modification significantly enhances the gas adsorption capability of ZrS₂, leading to notable changes in its electronic properties. For Pt@ZrS₂, the adsorption of gases such as CO, H₂S, NH₃, NO, SO₂, and SO₃ increases the band gap, which reduces conductivity, whereas NO₂ causes a decrease in the band gap, enhancing conductivity. In contrast, Pt-doped ZrS₂ shows a reduction in the band gap upon adsorption of most gases, except for SO₂, which increases the band gap. Sensitivity calculations indicate that Pt@ZrS₂ exhibits the highest sensitivity to CO and SO₂, with values of 156.72 and 33.56, respectively, at room temperature. Recovery time analysis demonstrates that Pt@ZrS₂ is suitable for real-time monitoring of SO₂, while Pt–doped ZrS₂ is ideal for real-time monitoring of CO and H₂S. These findings suggest that Pt–modified ZrS₂ monolayers have great potential for selective detection and real-time monitoring of harmful gases, making them promising candidates for environmental sensing applications.