Improvement in Toxic CO Detection Capabilities via Incorporating Pt Dopant into ZnO Nanotube Based Gas Sensor Devices: An Atomistic Modeling

This research work analyzes the improved sensing performance of platinum (Pt)-doped zinc oxide (ZnO) nanotube (NT) based sensor devices, over pristine ZnO NT, towards the detection of toxic carbon monoxide (CO). The study leverages first principles based computational approach using the Gaussian 09W and Gauss View 6.0 packages, examining them individually in two systems, where CO was being considered as the adsorbed gas for both pristine ZnO NT, and Pt-doped ZnO NT, leading to the formation of CO-adsorbed pristine ZnO NT (Type-1 system), and CO-adsorbed Pt-doped ZnO NT (Type-2 system). The interaction between them was meticulously explored through the calculation of various electronic characteristics like the Highest Occupied Molecular Orbital (HOMO), Lowest Unoccupied Molecular Orbital (LUMO), Molecular Electrostatic Potential (MEP), Density of States (DOS), and Mulliken charge analysis. The system's semi-metallic characteristic was verified by the computed DOS. Notably, the current study found that the material's reactivity of ZnO was significantly increased by doping it with platinum, which produced substantial adsorption energy (-0.7382 eV). The results indicated that the catalytic activity of the Pt atoms was responsible for the increased sensitivity towards the CO molecule identification.