Abstract:

The strontium tungstate （SrWO₄） photocatalyst with high oxygen defect and [WO₄] tetrahedral lattice distortion was synthesized by oxalic acid complexation method. The SrWO₄ photocatalyst was tetragonal phase, and the particles were approximately spherical and did not contain any impurities. There was a slight adhesion and agglomeration among the particles, and the average particle size was approximately 70 nm. The SrWO₄ photocatalyst exhibited two distinct blue emission peaks at 400 and 440 nm under the excitation peak of 280 nm. Chlortetracycline hydrochloride was used as the target antibiotic to be degraded. The effects of antibiotic concentration, catalyst content and pH value on the photocatalytic activity of SrWO₄ photocatalyst were studied. The experimental results showed that, the optimum antibiotic concentration, catalyst content and pH value for SrWO₄ photocatalyst to degrade chlortetracycline hydrochloride were 100 mg/L, 1 g/L and 5.6, respectively. The mechanism analysis showed that the oxygen defect and the lattice distortion of [WO₄] tetrahedron in SrWO₄ photocatalyst led to high photoluminescence and photocatalytic activity at the same time.

Key words: photocatalysis, oxalic acid complexation, strontium tungstate （SrWO₄）, emission peak, oxygen defect, lattice distortion