Abstract: Using well-dispersed Ta₂O₅ microspheres as supports, which were prepared by controlling the hydrolysis rates of tantalum ethoxide via the formation of glycolate in an acetone-water mixture, dispersible heterostructured In₂O₃/Ta₂O₅ composites were fabricated for photocatalytic hydrogen evolution under simulant solar light irradiation. The compositions, structure, morphologies, and optical absorption properties of these composites were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, transmission electron microscopy, and UV-Vis diffuse reflectance spectroscopy. The results show that in the as-prepared heterostructured In₂O₃/Ta₂O₅ composites, In₂O₃ nanoparticles are well distributed on the surface of Ta₂O₅ microspheres with a clear interface between the two phases. The incorporation of In₂O₃ extends the light absorption range and restricts photogenerated charge-carrier recombination, resulting in enhanced photocatalytic activity for hydrogen evolution.

Key words: well-dispersed microsphere, tantalum pentoxide, indium trioxide, heterostructure, photocatalysis, hydrogen production