Adsorption and Sensing Performance of Transition Metal Decorated Graphene Quantum Dots for AsH₃, NH₃, PH₃, and H₂S

We have conducted a systematic study employing density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM) to explore the gas sensing capabilities of nitrogen-doped single vacancy graphene quantum dots (SV/3N) decorated with transition metals (TM = Mn, Co, Cu). We have studied the interactions between TM@SV/3N and four different target gases (AsH₃, NH₃, PH₃, and H₂S) through the computation of adsorption energies, charge transfer, noncovalent interaction, density of states, band gap, and work function for 12 distinct adsorption systems. Our comprehensive analysis included an in-depth assessment of sensors' stability, sensitivity, selectivity, and reusability for practical applications. Our findings indicate that the Co@SV/3N surface strongly interacts with PH₃, with the highest adsorption energy (-1.15 eV). It shows remarkable sensitivity and selectivity toward PH₃, making it a promising candidate for PH₃ gas sensing applications. Similarly, Mn@SV/3N exhibits high sensitivity and selectivity toward NH₃, positioning it as a suitable candidate for NH₃ gas sensing applications. We believe this study will provide valuable theoretical guidance for developing TM@SV/3N-based gas sensors.