SEM micrographs of starting TiO2 (sample A) and TiO2-xNx (sample B) heated to various temperatures:
(1) starting TiO2 prepared from anatase ST 01, Ishihara Ltd., Japan, (2) TiO2-xNx (sample B) prepared by heating sample A in a
flow of NH3 at 575°C/3 h, (3) TiO2-xNx (sample B) annealed at 800°C, and (4) TiO2-xNx (sample B)
annealed at 950°C.
