Preparation and luminescence properties of Tb3+ doped SiO2 film on TiO2 nanotube arrays

TiO2 nanotube arrays (TiO2 NTs) are fabricated by anodic oxidation of titanium in NH4Cl + H2O and NH4F + HOCH2CH2OH electrolytes respectively, then TiO2 NTs coated with Tb3+ doped SiO2 films (Tb–SiO2/TiO2 NTs) are prepared by sol–gel method and dip-coating process. The luminescence properties of Tb–SiO2/TiO2 NTs are investigated by fluorescence spectrometer. Results show that TiO2 NTs can improve the luminescence properties of Tb–SiO2, especially the TiO2 NTs fabricated in NH4Cl + H2O electrolyte. The emission intensity of Tb–SiO2 on the TiO2 NTs fabricated in NH4Cl + H2O electrolyte is five times to that on the pure titanium sheet. Additionally, the effect of TiO2 NTs preparation conditions on the Tb–SiO2 luminescence properties is analyzed in detail, and the luminescence enhancement mechanism of Tb–SiO2 on TiO2 NTs is explained.