Transition Metal (Cu, Pd, and Ag)-Modified Nb 2 S 2 C Monolayer for Highly Efficient Catechol Sensing: A First-Principles Investigation.

Motivated by recent advancements and the escalating application of two-dimensional (2D) gas or molecule sensors, this study explores the potential of the 2D Nb 2 S 2 C monolayer for detecting biomolecule catechol ( Cc ), whose excess concentration is highly dangerous to living beings. We use first-principles density functional theory (DFT) calculations to assess the Cc sensing performance of pure and transition metal (TM = Cu, Pd, Ag)-modified Nb 2 S 2 C monolayers. The Nb 2 S 2 C monolayer belonging to the new class of synthesized 2D materials, TM carbo-chalcogenides (TMCC), combines distinctive properties from both TM dichalcogenides and TM carbides and exhibits physisorption (-0.66 eV) toward the Cc molecule. Notably, the surface modifications with these TMs significantly enhanced the adsorption energy of Cc . The chemisorption of the Cc molecule on the Pd to Cu-modified monolayer is demonstrated with adsorption energies ranging from -1.09 to -1.3 eV and is due to the robust charge transfer and orbital interactions between the valence orbitals of TMs and Cc . In addition, the modification of the surface by TM leads to an increased work function sensitivity toward the Cc molecule. The study establishes the thermal stability at 300 K and dynamic stability of TM-Nb 2 S 2 C through ab initio molecular dynamics (AIMD) simulations and Phonon calculations, respectively. The theoretical estimation of achievable recovery time at 400 and 450 K for Pd and Ag and at 500 K for the Cu-modified Nb 2 S 2 C monolayer, respectively, confirms the potential practical application of the sensor for Cc detection. These compelling characteristics position the Nb 2 S 2 C monolayer as a promising nanomaterial for detecting Cc molecules in the environment.