Abstract: The nanosized TiO₂ in the rutile phase was doped with alumina to suppress its photo-catalytic activity. The obtained samples were characterized by XRD, XPS, TEM and BET techniques.
The results show that the optimal calcination temperature is 800℃, and the optimal Al₂O₃ concentration is m(Al₂O₃):m(TiO₂)=1:5.
The growth of crystalline size and particle size is suppressed from adulteration. With the increase of m(Al₂O₃):m(TiO₂), the crystalline size and
particle size of nanosized TiO₂ decrease progressively, at the same time, the BET surface area and pore volume of nanosized TiO₂ increase. According
to the difference of electron binding energy and the variety of unit cell parameters, it can be inferred that the lattice of nanosized TiO₂ is doped
with Al³⁺. The saturated concentration of dopant is m(Al₂O₃):m(TiO₂)=1:20. When m(Al₂O₃):m(_TiO2)≥1:10, the crystal
structure of alumina appears.

Key words: nanosized TiO₂, rutile, alumina, doping, photo-catalytic activity