The Effects of Electron Beam Irradiation on Structural and Optical Properties of TiO2 Particles

The effect of electron irradiation on structural and optical properties of TiO2 particles has been studied. The crystallinity change was observed at low dose irradiation (4-20 kGy) while phase transformation from pure anatase to mixture of anatase-rutile was inevitable after 100 kGy without significant change in crystallinity. The highest fraction of rutile:anatase ratio was 20:80 obtained at 700 kGy. Morphology study demonstrated that TiO2 particles were spherical, nano-sized and heavily agglomerated with no obvious microstructural changes were observed after irradiation. The direct and indirect band gap (Eg) showed a decrement at low dose but re-increased after irradiation at >100 kGy. The highest Eg was at 700 kGy which can be explained by the changes of TiO2 atomic structure in the presence of mixture anatase:rutile. Therefore, the electron beam irradiation does affect both structural and optical properties of TiO2 nanoparticles. This is expected to affect the photocatalytic activity of TiO2.