Synthesis and characterization of BaWO₄:xTm³⁺,yPr³⁺ obtained by ultrasonic spray pyrolysis

In the present paper, BaWO₄:xTm³⁺,yPr³⁺ samples were synthesized by the ultrasonic spray pyrolysis process and the effect of doping on the structural and optical properties were analyzed. All XRD patterns were indexed by the scheelite-type tetragonal structure, without the presence of secondary phases, suggesting success in the Tm³⁺ and Pr³⁺ doping. The FESEM images showed than particles have sphere-like morphology with the presence of holes, irregularity, and pores on their surfaces. The bandgap of the BaWO₄:xTm³⁺,yPr³⁺ sample varied between 5.50 and 5.58 eV. The doping of Tm³⁺ and Pr³⁺ resulted in a reduction in the photocatalytic activity can be linked to a decrease of effective masses ratio electron/hole and an increase in the recombination rate.