Synthesis, characterization and visible-light photocatalytic activity of Bi24Al2O39 mesoporous hollow spheres

Bi24Al2O39 mesoporous hollow spheres were successfully prepared using carbonaceous polysaccharide microspheres as sacrificial cores. The Bi24Al2O39 samples have a spherical morphology with an average diameter of 4 mu m. The addition of citric acid played a crucial role in the formation of the Bi24Al2O39 mesoporous hollow spheres. A possible growth mechanism of these spheres has been proposed based on the experimental results. The photocatalytic degradation results indicate that the Bi24Al2O39 mesoporous hollow spheres exhibited good photocatalytic activity for the degradation of acid red G (ARG) and gaseous formaldehyde under visible-light irradiation. Finally, the radical species involved in the photocatalytic degradation process have been investigated.