Template-free synthesis of hierarchical constructed flower-like δ-Bi2O3 microspheres with photocatalytic performance

Step-wise self-assembled flower-like δ-Bi₂O₃ microspheres from nanoparticles to nanosheets to microspheres were fabricated via a simple hydrothermal process, using glycine and Bi (NO₃)₃·5H₂O as starting materials without other additives. The crystal structures and morphologies of the as-obtained samples were characterised by X-ray powder diffraction, field emission scanning electron microscope and transmission electron microscopy. The UV-vis diffuse reflectance spectrum of the sample showed the product has an intense absorption in UV light regions and an estimated bandgap 3.55-eV. Moreover, under UV-light irradiation the sample exhibited high photocatalytic behaviour for the degradation of rhodamine B dye and excellent stability, which possibly has a board application in wastewater disposal fields.