First-principle studies of the magnetism and optical properties of (Sc, Y)-codoped anatase TiO2 (101) surface

We calculated the electronic structure, magnetism and optical properties of the Sc-doped, Y-doped, and (Sc, Y)-codoped anatase TiO2 (101) surface using a projector augmented wave (PAW) method with GGA+U approximation. Sixteen doping systems were considered in the present work. The lattice distortion results in the generation of an internal local electric field. In addition, the difference between positive and negative spin charge densities leads to the generation of magnetism. With the exception of the Sc@in2 system, the width of band gap of the other doping systems increases to varying degrees, leading to a blueshift of the absorption edge. The photocatalytic activity of all the doping systems was improved to different degrees. The absorption intensity and absorption range of the Sc@in2&Y@013 system in the visible-light region is the highest amongst all doping systems. This mainly attributed to the formation of hole states and the presence of impurity bands. (C) 2019 Elsevier B.V. All rights reserved.