First-principles investigation of iodine doped rutile TiO2(110) surface

Abstract

The formation energy and electronic structure of iodine (I)-doped rutile TiO2(110) surface are investigated using the first-principles method based on the density functional theory. The results indicate that I prefers to replace the five-coordinated Ti in the oxidation environment and the bridging O could be replaced by I preferentially in the reducing environment. Whether I replaces O or Ti can reduce the band gap and cause the red shift of the absorption band edge or produce the absorption in the visible light. The band gap narrows most obviously when I replaces the bridging O. The absorption spectrum shows that I doping could not only improve its visible light response but also enhance its absorption peak of UV-light, leading to the improvement in photocatalytic performance under visible and UV light.