ABSTRACT
Fe3O4/CdWO4 and Fe3O4/CdWO4/PrVO4 magnetic nanoparticles were prepared at different molar ratios of PrVO4 to previous layers (Fe3O4/CdWO4) via the co-precipitation method assisted by a sonochemical procedure, in order to investigate the photocatalytic performance of these systems and their cytotoxicity properties. The physico-chemical properties of these magnetic nanoparticles were determined via several experimental methods: X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier transformation infrared spectroscopy and ultraviolet-visible diffuse reflection spectroscopy, using a vibrating sample magnetometer and a scanning electron microscope. The average sizes of these nanoparticles were found to be in the range of 60-100 nm. The photocatalytic efficiency of the prepared nanostructures was measured by methylene blue degradation under visible light (assisted by H2O2). The magnetic nanosystem with a 1:2:1 ratio of three oxide components showed the best performance by the degradation of ca. 70% after 120 min of exposure to visible light irradiation. Afterwards, this sample was used for the photodegradation of methyl orange, methyl violet, fenitrothion, and rhodamine-B pollutants. Finally, the mechanism of the photocatalytic reaction was examined by releasing ËOH under UV light in a system including terephthalic acid, as well as O2-, OH, and hole scavengers. Additionally, the cytotoxicity of each synthesized sample was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay against the human cell line PANC1 (cancer), and its IC50 was approximately 125 mg/L.
ABSTRACT
Thulium titanate/polyaniline nanocomposites were synthesized to observe the sonophotocatalytic degradation of dyes (widely used as a model pollutant) under ultrasonic irradiation and visible light. Based on our results, the synthesis process can improve sol-gel assisted sonochemical method in the presence of ultrasound and starch. To prepare pure thulium titanate nanostructures, the presence of starch and sonication treatment were concurrently obligatory. Therefore, sol-gel assisted sonochemical method can be used as a successful process for synthesis of thulium titanate nanostructures. According to the BET results, in the presence of ultrasound and starch surface area increased from 9.5305â¯m2/g to 40.28â¯m2/g. For verification of photacatalytic behavior of nanoparticles, several factors were studied. The nanocomposites/ultrasonic system showed greater photocatalytic activity for the degradation of Rh B rather than separately treatment of nanocomposites under visible light.
ABSTRACT
YbVO4 nanostructure and YbVO4/CuWO4 nanocomposites were successfully synthesized using sonochemical method, for the first time. In this disquisition, we tried to compare various parameters and reaction conditions on size, morphology, and uniformity of as-obtained samples. To reach optimum condition, some parameters including time, power, temperature, and solvent were investigated. The structural, morphological, optical, and magnetic properties of as-obtained products were characterized by some techniques such as FT-IR, XRD, EDS, SEM, TEM, UV-Vis, and VSM. Furthermore, due to occurrence of red shift in nonanocomposite, during the coupling of CuWO4 into YbVO4, photocatalytic and optical properties of final products were improved which lead to improve photo-destruction efficiency for methylene blue from 65% to 100%, during 120â¯min irradiation. The effect of the ultrasonic radiation on the photocatalytic behavior of YbVO4/CuWO4 shows that methylene blue pollutant destruction was about 100% with ultrasonic wave and 61% in the absence of ultrasonic radiation.
