Hydrothermal Synthesis of Mesoporous Bi2O3/Co3O4 Microsphere and Photocatalytic Degradation of Orange II Dyes by Visible Light

New visible-light-responsive porous Bi2O3/Co3O4 microspheres have been successfully synthesized by hydrothermal method in ethylene glycol (EG) accompanied with the addition of polyethyleneglycol (PEG) and sodium acetate. PEG can enter into the initial nuclei because of the similar structure and composition with EG, resulting in the formation of hollow porous structures. The specific surface area incorporating bismuth and cobalt oxides is enlarged by comparing with their pristine forms. According to the photocatalysis results, Bi2O3/Co3O4 composite microsphere is more effective to degrade Orange II dye than pure Bi2O3 photocatalyst by better utilizing visible light activities.