The structural defects and UV–VIS spectral characterization of TiO2 particles doped in the lattice with Cr3+ cations

Titania nanoparticles doped with Cr3+ (2% relative to molar quantity of titania) were prepared and examined by EDS, HRTEM, XRD, and UV–VIS analysis. HRTEM images showed the detailed atomic arrays and vacancy defects of the doped Titania nanocrystals and revealed that the implanted Cr element existed in titania mainly as Cr3+ ions which located at the lattice positions of Ti4+ ions. Compared with pure titania, the UV–VIS spectra of the Cr3+ doped titania show significantly increased absorbance in visible light region. This indicated that the presence of the Cr3+ ions affected the lattice structure of titania nanocrystals and plays an reformative role in spectral feature of titania.