Sonochemical synthesis of Pr6MoO12 nanostructures as an effective photocatalyst for waste-water treatment

•Pure Pr6MoO12 nanostructures were synthesized by sonochemical method.•To achieve the desired product various parameters were changed.•The results showed that increasing the time and power of sonication can have negative effect on size.•The photocatalytic activity of pure Pr6MoO12 nanostructures under UV irradiation was studied.•Kinetics studies showed that the photo-degradation reactions followed Pseudo-first order model. Synthesis of pure Pr6MoO12 nanoparticles was the aim of the present work, which was prepared by sonochemical method which is a controllable rout on size, purity, and morphology of products. The experiments were carried out under a probe as sonication source, and its power was adjusted in 30 W (9 kHz), 50 W (15 kHz), and 80 W (24 kHz) for different samples. The optimum product with the smallest size and highest purity was synthesized by changing time, power of sonication, solvent and capping agent. Besides, the formation of various phases of praseodymium molybdate was investigated in different experimental conditions that proved the presence of ammonia, sonication and calcination are necessary factors for the preparation of pure Pr6MoO12 nanoparticles. Products were characterized by various analyses such as SEM, XRD, TEM, FT-IR, DRS, and EDS. Furthermore, the photocatalytic activity of Pr6MoO12 nanoparticles under UV irradiation was studied by photodegradation of methylene blue and acid red 92 as organic pollutants. The most active photocatalytic agent was determined superoxide anion radicals and kinetics model of photocatalytic reaction was considered as pseudo-first order.