Modulating MoS₂ Substrate via d-p Orbital Hybridization Driven by π-Electron Feedback Effect for Dual-Site Adsorption...

Two-dimensional transition metal chalcogenides (TMCs), such as MoS₂ (MS), exhibit chemically inert basal planes due to saturated intralayer coordination. This inherent inertness limits their specific recognition and adsorption of target gas molecules as gas-sensitive materials. Based on density functional theory (DFT) calculations, we report a strategy to achieve efficient formaldehyde adsorption by enhancing d-p orbital hybridization within the MS lattice to establish a π-electron feedback mechanism. Specifically, codoping the lattice with transition metal Zr atoms and nonmetallic N atoms strengthens the matrix's d-p orbital hybridization, thereby inducing a π-back-donation effect at the MS-Zr-N/formaldehyde (CH₂O) interface. Notably, this π-electron feedback mechanism facilitates the formation of dual adsorption sites between the MS-Zr-N substrate and formaldehyde molecules, significantly enhancing specific adsorption capacity. Consequently, the MS-Zr-N substrate demonstrates high adsorption stability (adsorption energy: - 3.023 eV), superior sensitivity (38.47), and excellent selectivity toward formaldehyde. This work provides theoretical guidance for designing gas-sensitive materials from the perspective of orbital hybridization and interfacial electron feedback in adsorption systems.