Electronic and structural properties of functionalized Silica nanoparticles: DFT and SCC DFTB calculation

Abstract

Abstract Silica nanoparticles (SNP) are extremely promising tools in nanotechnology and nanomedicine. In this investigation, we aim at obtaining the optimized structures and evaluate the geometries of the ground state for (SiO2) n (n = 16,20) nanoclusters. The electronic properties computed by density functional theory (DFT) with GGA approximation and also SCC-DFTB with hybrid Slater-Koster files are investigated and the effect of functionalization on such properties is discussed. Solvolysis of these structures is examined and it is shown that the highest occupied and lowest unoccupied molecular orbital states shift to obviously higher energy levels which lead to more stable hydrogenated nanoclusters. The stability of nanoclusters rises by functionalization with amino and methylamine groups. Charge analysis of functionalized systems indicates the reactivity of nanoclusters. The results obtained in this paper are useful for chemical and biochemical applications of silica nanostructures.