Effects of Nd-doping on crystal phase, structure and photocatalytic performance of TiO₂ powders prepared by sol-gel method

In this work, 0.3–2 mol% neodymium (Nd) doped titanium dioxide (TiO 2 ) powder was prepared by sol–gel method. The XRD showed that the anatase phase occur for the Nd doped TiO 2 powders, and the Nd doping suppressed the original rutile phase for the pure TiO 2 powder. SEM and TEM revealed that Nd doping reduced the tendency of severe aggregation and increased the specific surface area compare with pure TiO 2 powder, and the Gibbs free energy difference did not reach the critical value of the phase transition driving force, while the adjustment of the Ti-O bond length caused by the addition of Nd 3+ impeded the transformation of TiO 2 to rutile phase. The photocatalytic activity test results for Methylene blue show that the 0.5 mol% Nd doped TiO 2 had the best photocatalytic activity with the degradation efficiency of 96.2%.