Modulation of Electro-Chemical Sensing Properties in MoSe₂ Nanosheet towards CO Detection via Incorporating Foreign Platinum Atom

The current study investigates the electronic and chemo-sensing properties of a pristine 2D molybdenum diselenide (MoSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) nanosheet and a platinum (Pt)-doped MoSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> nanosheet, concerning their ability in adsorbing toxic carbon monoxide (CO) gas. First principle-based calculations were performed to analyze the adsorption characteristics of CO on pristine MoSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> (System I) and Pt-doped MoSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> (System II), using the Gaussian 09W and GaussView 6.0 software packages. Various electronic properties, including the Highest Occupied Molecular Orbital (HOMO), Lowest Unoccupied Molecular Orbital (LUMO), Electrostatic Potential (ESP), and Electron Localization Function (ELF), were examined, to elucidate the atomic-level interactions between CO and the two considered nanosheets. To visualize the electron localization/delocalization present within the molecular and atomic structure, ELF mapping was employed. The molecular structures of both systems were analyzed using infrared (IR) spectroscopy. Calculations revealed that CO exhibited stronger interaction with the pristine MoSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> nanosheet compared to the Pt-decorated one, as indicated by a higher negative value (in magnitude) of adsorption energy (-1.98 eV) for System-I. For both the systems recovery time (in seconds) and electronic conductivity, were measured. FTIR and Raman spectroscopy were plotted for CO adsorbed Pt-doped MoSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> nanosheet to analyze the results with experimental verification. The findings inferred that Pt cannot be considered as a suitable dopant for enhancing CO detection in MoSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> nanosheets.