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.