In the present work, a new way to obtain bimetallic nanoclusters of different structures and chemical compositions is proposed, which is based on computer simulations. Collision processes between two metal clusters of different natures are simulated through molecular-dynamics simulations using many-body potentials. Diverse diffusion mechanisms and structures can be observed, depending on the metals combined and the initial kinetic energies. The nanostructures we have found are core-shell (Pt–Au), alloyed (Pd–Au), and three-shell onionlike (Cu–Ag).

The present work is based on the theoretical study of the behavior of a graphene sheet decorated with titanium, in contact with different molecules. When the substrate is exposed only to hydrogen molecules, it is found to store up to four molecules per adatom, as already seen in the literature for single wall carbon nanotubes. Thus, titanium decoration is seen to considerably improve the hydrogen storage capacity of these carbon systems. However, it is found that low quantities of oxygen present in the gas phase should yield the oxidation of the titanium atoms, even when hydrogen is stored in the system. It is concluded that if the experimental system is exposed to air, titanium atoms on these surfaces are expected to oxidize to titanium dioxide, showing oxygen molecules to be very reactive species. Other chemicals present in air such as nitrogen or water molecules could also be chemisorbed onto the titanium adatom, but are less competitive with hydrogen.