Synthesis and characterization of nanoparticles of alpha-Bi_2Mo_3O_(12) prepared by co-precipitation method: Langmuir adsorption parameters and photocatalytic properties with rhodamine B

摘要

Nanoparticles of alpha-Bi_2MO_3O_(12) were prepared by co-precipitation method at calcination temperatures of 250, 300, 400 and 480 deg C. The characterization of alpha-Bi_2MO_3O_(12) synthesized at different temperatures was carried out by X-ray diffraction (XRD), thermal analysis (TGA/DTA), transmission electron microscopy (TEM), and diffuse reflectance spectroscopy (DRS). Adsorption parameters and photocatalytical activity under visible light irradiation of alpha-Bi_2MO_3O_(12) were evaluated using the rhodamine B (rhB) dye as model. The adsorption constant (K) and maximum amount of dye adsorbed (q_(max)) on the surface of the samples synthesized were evaluated following the Langmuir isotherm. The sample calcinated at 250 deg C showed the maximum adsorption percentage of dye, which ranged between 20 and 46 percent for initial concentrations ofrhB from 5 to 15 mg L~(-1), with a K =6.96 x 10~5 L mor~(-1) and q_(max) = 2.73 mgg~(-1).All samples were able to induce the oxidative photodegradation of rhB, however, the bleaching of dye solution was reached more quickly for the sample calcinated at 250 deg C.