Nanosheets-Based Rhombohedral In2O3 3D Hierarchical Microspheres: Synthesis, Growth Mechanism, and Optical Properties

In this Article, we demonstrate a new synthesis route for the construction of rhombohedral In2O3 (rh-In2O3) nanosheets-based three-dimensional flowerlike microspheres (NBFMs). In this route, InOOH NBFMs were first prepared by a convenient and controllable method based on a complex reaction, using InCl3 center dot 4H(2)O as the starting material, oxalic acid as the complexing agent, and a mixture of glycerol and water as solvent at 180 degrees C for 12 h. The rh-In2O3 NBFMs were then obtained by calcining InOOH NBFMs precursors at 490 degrees C under ambient pressure. Scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, infrared spectroscopy, and thermogravimetric analysis were adopted to investigate the evolution process of InOOH precursors, and the chemical reactions at each stage were identified. The Ostwald ripening and anisotropic crystal structure are proposed to account for the formation of InOOH NBFMs on the basis of the evaluation of the time-dependent morphology. Furthermore, the influence of solvent on the morphologies and the photoluminescence properties of the rh-In2O3 NBFMs were investigated.