A simple route to the water-repellent surface based on chemical N modified Ti–O structure films

The water-repellent surface based on chemical N modified Ti–O amorphous film with water contact angle of 118° was prepared by RF magnetron sputtering in the mixture of N2 and O2 from a metal Ti disk. The XPS analysis shows that the N element exists in three forms, including atomic β-N (interstitial state), chemisorbed γ-N2 on the TiO2 surface and Ti–N bonds. It is considered that the chemisorbed γ-N2 and Ti–N bonds on the surface are helpful to decrease the surface energy, resulting in the water-repellent surface.