Bi60In2O93 Nanoparticles: Photocatalytic Activity Investigation

Objective: Synthesis and characterization of bismuth indium oxide (Bi60In2O93) nanoparticles and their evaluation as new visible lightsensitive photocatalysts. Methods: Synthesis was achieved using a simple hydrothermal method at low temperature and the crystal structures and morphology of the prepared Bi60In2O93 nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Optical properties of the nanoparticles were measured by UV-visible spectroscopy and photocatalytic activity was tested by measuring their effects on rhodamine-B degradation under UVvisible and visible light. Results: The prepared samples had high crystallinity and were tetragonal. Bi60In2O93 nanoparticles exhibited strong photocatalytic activity under simulated sunlight. Nanoparticles prepared from a Bi:In mole ratio of 12:1 had the smallest size (~75 nm in diameter) and were the most uniform with good spherical morphology. These particles showed the strongest photocatalytic activity, including activity in the visible region. The possible mechanism for activity enhancement of Bi60In2O93 nanoparticles compared with Bi2O3 was investigated. The enhanced degradation of rhodamine-B, which is promoted by dye sensitization, is related to the higher crystallinity, unique tunnel structure, narrower band gap and special electron structure of the Bi60In2O93 nanoparticles. Conclusion: Bi60In2O93 nanoparticles show good promise as visible light-sensitive photocatalysts and for semiconductor development.