NiMo alloy surface segregation inducedby water adsorption

In recent years it has been a general idea that the structure and property of metal nanoparticle can be largely influenced by the environment condition. It has been proved that the reactive gases can induce the surface segregation of metallic nanoalloy and determine its physical and chemical property. On the other hand, the effect of water, one of the most ubiquitous environments on the planet, on the alloy segregation has not been studied properly. In this work we performed first principle calculations and statistic Monte-Carlo simulations as well to study the effect of water adsorption on the segregation behavior of NiMo alloy. It is show firstly the adsorption of water can change the segregation energy of Mo atom on Ni (111) surface, and secondly a humid or water environment can change the surface composition of NiMo nanoalloy. By this work we hope to call attentions to the issue of alloy segregation in water and help to understand the mechanism of corrosion of NiMo alloy.