New anatase-type Ti1-2XNbXAlXO2 solid solution nanoparticles:: Direct formation, phase stability, and photocatalytic performance

New anatase-type titania solid solutions co-doped with niobium and aluminum (Ti1-2xNbxAlxO2 (X = 0 similar to 0.20)) were synthesized as nanoparticles from precursor solutions of TiOSO4, NbCl5, and Al(NO3)(3) under mild hydrothermal conditions at 180 degrees C for 5 h using the hydrolysis of urea. The lattice parameters a(0) and c(0) of anatase slightly and gradually increased, when the content of niobium and aluminum increased from X = 0 to 0.20. The crystallite size of anatase increased from 12 to 28 nm with increasing the value of X from 0 to 0.20. Their photocatalytic activity and adsorptivity were evaluated separately by the measurement of the concentration of methylene blue (MB) remained in the solution in the dark or under LIV-light irradiation. The adsorptivity of 702 was improved by the formation of anatase-type Ti1-2xNbxAlxO2 solid solutions. The photocatalytic activity of anatase-type Ti1-2xNbxAlxO2 Solid solutions was superior to the at of commercially available anatase-type pure TiO2 (ST-01) and anatase-type pure TiO2 hydrothermally prepared. The new anatase phase of Ti1-2xNbxAlxO2 (X = 0 similar to 0.20) solid solutions existed stably up to 850 degrees C during heat treatment in air. In comparison with hydrothermal pure TiO2, the starting temperature of anatase-to-rutile phase transformation was delayed by the formation of Ti1-2xNbxAlxO2 (X = 0 0.20) solid solutions, although its completing temperature was accelerated.