N–TiO2 nanoparticles embedded in silica prepared by Ti ion implantation and annealing in nitrogen

✍ Scribed by X. Xiang; M. Chen; Y.F. Ju; X.T. Zu; L.M. Wang; Y. Zhang

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 617 KB
• Volume: 268
• Category: Article
• ISSN: 0168-583X
• DOI: 10.1016/j.nimb.2010.01.023

✦ Synopsis

Room-temperature Ti ion implantation and subsequent thermal annealing in N 2 ambience have been used to fabricate the anatase and rutile structured N-doped TiO 2 particles embedded in the surface region of fused silica. The Stopping and Range of Ions in Matter (SRIM) code simulation indicates a Gaussian distribution of implanted Ti, peaked at $75 nm with a full width at half maximum of $80 nm. However, the transmission electron microscopy image shows a much shallower distribution to depth of $70 nm. Significant sputtering loss of silica substrates has occurred during implantation. Nanoparticles with size of 10-20 nm in diameter have formed after implantation. X-ray photoelectron spectroscopy indicates the coexistence of TiO 2 and metallic Ti in the as-implanted samples. Metallic Ti is oxidized to anatase TiO 2 after annealing at 600 °C, while rutile TiO 2 forms by phase transformation after annealing at 900 °C. At the same time, N-Ti-O, Ti-O-N and/or Ti-N-O linkages have formed in the lattice of TiO 2 . A red shift of 0.34 eV in the absorption edge is obtained for N-doped anatase TiO 2 after annealing at 600 °C for 6 h. The absorbance increases in the ultraviolet and visible waveband.