Microemulsion-mediated preparation of Ce2(MoO4)3 nanoparticles for photocatalytic degradation of crystal violet in aqueous solution.

Preparation of Ce2(MoO4)3 nanoparticles is reported via the microemulsion method by using two different surfactants, i.e., cationic surfactant, cetyltrimethylammonium bromide (CTAB), and nonionic surfactant, Triton X-100. The water pools produced in the microemulsion systems behave as nanoreactors for reaction of the cerium (3+) and molybdate ions to produce Ce2(MoO4)3 nanoparticles. The structure and morphology of the products were characterized by using Fourier-transform infrared (FT-IR) spectroscopy, energy-dispersive X-ray analysis (EDX), UV-Vis spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA-DTA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The prepared Ce2(MoO4)3 nanoparticles were successfully utilized as photocatalysts to remove crystal violet from aqueous solution in which the maximum percentage of dye degradation was about 89% after 5 h under the visible light irradiation. Also, kinetic study of the photocatalytic degradation revealed that pseudo-second order model is the best one for describing kinetic of the reaction.

Highly efficient absorption of cationic dyes by nano composite hydrogels based on κ-carrageenan and nano silver chloride.

Novel nanocomposite hydrogel was synthesized based on κ-carrageenan and nano-silver chloride by a simple method and applied for the removal of cationic dyes in aqueous solution. Inclusion of nano-silver chloride into the superabsorbent hydrogel was utilized for producing the effective dye absorbent. The dye absorption was more than 98% after 5min in a 10ppm aqueous solution at pH=6. The nanocomposite hydrogel was characterized by FT-IR spectroscopy, SEM, TEM, TGA/DTG, and BET analysis. The absorption of crystal violet was investigated by changing the absorbent dosage, contact time, dye concentration, pH, and temperature. Several kinetic models were used to predict the kinetic behavior of the dye absorption. The best result was obtained with the pseudo-second order model. The results demonstrated that the Temkin model has been fitted better than the other models. The reusability experiments showed that the superabsorbent retained more than 60% of initial activity after 9 cycles.