Investigation of modelling of nano-structures and their interactions with molecules/atomic clusters by atomistic simulation methods

In this doctoral thesis, gold-based nano-structures and their interactions with molecules and atomic clusters were systematically investigated using atomistic simulation methods. Specifically, Au2H, Ag2H, Cu2H, Pd2H and Pt2H surfaces and their Mn-doped variants were modelled based on Density Functional Theory (YFT). Additionally, magnetic, electronic, and physicochemical properties of gold nanoclusters such as Au6, Au8, Au9, their Mn-doped derivatives and MAu8 (M= Fe, Co, N, Pd and Pt) nanoclusters were evaluated. The interactions of Au2H nanosurface with H atom and H2 and O2 molecules under magnetic moment were investigated, and also the interaction of the Boron atom and molecule with 2H nano-surfaces is also presented. The effects of Mn doping on magnetization, energy band gaps, work functions, and reactivity parameters were systematically analyzed. Furthermore, the interactions of benzene (C6H6) molecules with the surfaces and nanoclusters were examined. Löwdin charge distributions, HOMO-LUMO energy levels, chemical hardness, electrophilicity index, and other physicochemical parameters were calculated and compared with the literatüre 2D carbon-based graphdiyne(GDY) and S-, O- and Mn-doped GDY nanostructures and their derivatives were investigated, and the interactions of hydrogen (H2) and hydrogen peroxide (H2O2) with the structures were presented. All calculations were performed using the Quantum Espresso software, based on plane-wave and ultrasoft pseudopotentials. The results indicate that gold and transition metal-doped nanostructures at the nanoscale hold promising potential for spintronic, sensing, and catalytic applications.