Aims: We investigate the structural and morphological features as well as the sonophotocatalytic
properties of (Ca1-xSrx)WO4 (x = 0.25; 0.50; 0.75 and 1) synthesized by the sonochemical method (SC). The
as-synthesized samples were structurally characterized by X-ray diffraction (XRD), Rietveld refinement,
micro-Raman, and Fourier-transform infrared (FT–IR) spectroscopies. Field-emission scanning electron
microscopy (FE–SEM) and energy-dispersive X-ray spectroscopy (EDX) were used to analyze the morphological
aspects and elemental chemical composition, respectively.
Background: Currently, environmental issues have been one of the main concerns in the world, especially
the contamination of freshwater supplies. Hence, environmental scientists have an enormous interest in developing
efficient wastewater treatment technologies to remove harmful substances from contaminated water
resources. In general, synthetic organic dyes and pigments, widely employed as coloring agents in leather
or textile industries, severely impact the environment because of their toxic and carcinogenic nature.
When discharged into water sources, such chemical pollutants have an irreversible and devastating impact
on flora and fauna. As an alternative route to minimize these negative impacts, heterogeneous photocatalysis
has emerged as a low-cost, safe, and versatile wastewater treatment approach.
Objective: To analyze the effect of different strontium (Sr) contents (x = 0, 0.25, 0.50, 0.75, and 1) on the
structural, morphological, optical, and sonophotocatalytic (SPC) properties of (Ca1-xSrx)WO4 samples.
Methods: (Ca1-xSrx)WO4 (x = 0, 0.25, 0.50, 0.75, and 1) were synthesized by the sonochemical method at 40
ºC for 3 h.
Results: XRD patterns, Rietveld refinement data, and micro-Raman and FT–IR spectra proved that all samples
are structurally organized in a scheelite-type tetragonal structure without deleterious phases. FE–SEM
images showed the growth of flower- and spindle-like crystals. UV–Vis spectra indicated that the increase
of Egap (from 4.68 to 4.94 eV) in (Ca1-xSrx)WO4 samples was proportional to Sr concentration inserted into
Conclusion: Among all samples, CaWO4 exhibited the highest SPC performance for the degradation of
RhB solution under UV irradiation. When irradiated for 200 min, a degradation rate of around 96% was
achieved for this sample. The ultrasound-assisted photocatalysis proved to be a promising approach for the
degradation of organic dyes.