Hybrid Bi₂SiO₅ mesoporous microspheres with light response for environment decontamination

A hybrid mesostructured photocatalyst prepared by using the " postsynthetic modification" approach with the periodic mesoporous organosilicas (PMO) framework and bismuth nitrate was studied. The morphology and structure of the hybrid Bi₂SiO₅ photocatalyst were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and N₂ adsorption-desorption isotherms. These results of characterization show that the as-prepared Bi₂SiO₅ keeps a semi-ordered mesostructure as the PMO framework. The results of density functional theory calculations indicated that the conduction band bottom of Bi₂SiO₅ mainly consist of Bi 6s orbits and O 2p, O 2s, while the valence band top mainly consist of Si 3p, O 2p, and Bi 5d orbits. The as-prepared Bi₂SiO₅ exhibited efficient photocatalytic activity in the decomposition of a widely used dye, tetraethylated rhodamine (RhB), and phenol in water under the simulative sunlight irradiation. Further, the photocatalytic experiment results show that the hybrid Bi₂SiO₅ synthesized based on PMO was more efficient than the pure mesoporous Bi₂SiO₅ in decomposing the organic pollutant, which means the hybrid organic groups dispersed in the PMO framework is advantageous to improve the efficiency of the photocatalyst.