Fabrication of Bi2SiO5 hierarchical microspheres with an efficient photocatalytic performance for rhodamine B and phenol removal

Self-assembled three-dimensional (3D) Bi2SiO5 microspheres were synthesized via a solvothermal method using glycerol as reaction media and NH3 center dot H2O as pH adjustment. The growth of Bi2SiO5 crystal was influenced by the solvothermal time. During the preparation process, glycerol acts as a soft template to guide the formation of the hierarchical microspheres. The photocatalytic activities of Bi2SiO5 microspheres toward the degradation of Rhodamine B and phenol under light irradiation were evaluated. Bi2SiO5 microspheres display much higher photocatalytic activity than the Bi2SiO5 nanoplates. The high photocatalytic activity of hierarchical Bi2SiO5 microspheres can be ascribed to the enhanced light absorbance, the efficient separation of photo-generated electrons and holes and the large surface area. The main active species during the photocatalytic reaction are center dot OH and center dot O-2(-), proven by terephthalic acid photoluminescence probing technique and nitroblue tetrazolium (NBT) experiments. The Bi2SiO5 microspheres are stable during the photocatalytic reaction and can be used repeatedly.