Photocatalytic Activity of LaSr 2 AlO 5 :Eu Ceramic Powders

The photocatalytic activity, of undoped and Europium‐doped LaSr 2 AlO 5 powders, has been investigated by degrading methylene blue dye in water solutions. Those powders were fabricated by a combustion method and an annealing treatment in air. All samples showed a tetragonal single phase according to by X‐ray diffraction measurements ( XRD ). Scanning electron microscopy ( SEM ) revealed irregular semi‐oval grains with sizes in the range of 3.5–4.27  μ m. Photoluminescence spectrum showed sharp emission peaks at 588 nm and at 617 nm which are associated with 7 F 1 , 7 F 2 → 5 D 0 Eu 3+ ion forbidden transitions, respectively, under UV light excitation of 322 nm. The methylene blue ( MB ) degradation under UV light (254 nm) was studied by monitoring changes in the absorbance peak of MB at 665 nm. Finally, LaSr 2 AlO 5 :Eu powders were used three times and the efficiency for the degradation of MB decreased from 100 to 61% after the third cycle of use.