ReaxFF reactive molecular dynamics study on oxidation behavior of 3C-SiC in H2O and O2

[Display omitted] •Oxygen has a stronger oxidation and diffusion capacity than water.•The oxidation resistance of Si surface is stronger than that of C surface.•The coupling effect of water and oxygen accelerates the oxidation of SiC.•Water molecular leads to the separation of Si atoms and the porous oxide layer. Simulations of the initial oxidation process of 3C-SiC involving different polar surfaces C (1-00), C(1-1-1-),Si (100), and Si (111) exposed to H2O were studied by ReaxFF. The results show that SiC is gradually converted into silicon oxide and forms low-density carbon chains. The activation energy of the C face is lower than that of the Si face, which reflects lower oxidative stability. In addition, an oxidation reaction was carried out on a C (100) surface with different concentration ratios of H2O and O2. The results indicate the reaction rate of O2 is much higher than that of H2O, while the oxidation capacity of O2 is effectively improved with the addition of water. It is clearly observable that the addition of water leads to the porosity of the oxide layer and the separation of Si atoms.