A reactive force field molecular dynamics simulation study of corrosion of nickel
Résumé
The interaction of water molecules on a nickel surface was studied using ReaxFF (reactive force field) molecular dynamics. This approach was originally developed by van Duin et al. to study the hydrocarbon chemistry and the catalytic properties of organic compounds. To our knowledge, this method has not been used to study the corrosion processes of nickel exposed to water, which is what we set out to achieve in the present investigation. To do so, calculations were first performed using ReaxFF in order to reproduce certain well-known properties of pure nickel and nickel-water systems. This allowed us to study the adsorption of a single water molecule interacting with an optimized nickel surface. We also investigated the interaction of 405 molecules of water (rho=0.99 g.cm(-3)) on the (100), (110) and (111) surfaces of a single crystal of nickel at 300 K. The results show that a water 'bilayer' is adsorbed on nickel surfaces: the first water layer is directly bonded to the surface, whereas the molecules in the first and second layers are held together by hydrogen bonds.