By plane-wave pseudopotential techniques we simulated structural and electronic properties of novel two-dimensional (2D) materials composed of Si and Ge randomly placed at the lattice sites of a honeycomb structure: 2D-Si1−xGex, and 2D-(H@Si)1−x(Ge@H)x, the corresponding H-passivated alloy. We investigated the formation of a random network of Si and Ge in 2D-honeycomb structure and proved the thermal stability of H-passivated SiGe alloy by computing the formation energy of these 2D-compounds. The 2D-Si1−xGex random alloy is a semi-metal and presents at the Fermi energy a density of states resembling the one produced by the Dirac’s cone of silicene and germanene, suggesting the possibility to induce, in 2D-Si1−xGex Dirac’s cone, a population of high velocity carriers that behaves like massless Dirac fermions. The 2D-(H@Si)1−x(Ge@H)x random alloy is a semiconductor and …