Exploring TM-Doped arsenene allotropes (TM = Ti, Ni, Ag) as efficient materials for CO, NO and N2O gas capture: Insights from DFT

Despite the urgent global need to mitigate rising greenhouse gas emissions, the identification of effective materials for gas capture and detection remains a significant challenge. Two-dimensional nanomaterials have emerged as promising candidates due to their exceptionally high surface-to-volume ratios and tunable electronic properties. In this work, density functional theory (DFT) calculations were performed to investigate arsenene allotropes ( α -, β -, and γ -phases) doped with transition metal ( TM = Ti , Ni , and Ag ) to evaluate their structural stability, and electronic properties for the adsorption of CO , NO , and N 2 O molecules. The cohesive energies of the TM-doped arsenene allotropes were located between 2.97 and 3.11 eV/atom, close to the bulk phases ( ≈ 3.0 eV). The formation energy of Ti-doped α -arsenene ( E f = − 6.75 eV) indicates high experimental feasibility, while Ti-doped γ -arsenene exhibits a slightly endothermic E f = 0.05 eV. Furthermore, arsenene monolayers doped with Ti and Ni exhibit superior adsorption affinities for all investigated greenhouse gases. Mülliken analysis population, electronic band structure, and density of state (DOS/PDOS), reveals a strong orbital hybridization between metallic TM d -orbitals and the p -orbitals of greenhouse gases. Additionally, electronic charge density difference maps revealed significant charge redistribution, wherein the doped substrates act as efficient electron donors, promoting substantial charge accumulation within the interaction region. Consequently, these findings suggest that the TM-doped arsenene allotropes, serve as support material with potential applications of photocatalysis, greenhouse gases capture or high-sensitivity gas-sensing.