Corundum-Type In2O3 Urchin-Like Nanostructures: Synthesis Derived from Orthorhombic InOOH and Application in Photocatalysis

A facile route was applied to synthesize indium oxyhydroxide (InOOH) with - urchin-like nanostructures through polymer-assisted hydrolysis of the In 31 cation in water/ethanol mixed solvent. The uniform InOOH urchin-like nanostructures are composed of nanorods with a diameter of several nanometers and a length up to 100 nm. Investigation of the effects of various reaction parameters reveals that poly(ethylene glycol)-1000 (PEG-1000) and reaction temperature have significant influences on the morphology of the as-prepared products. The formation of InOOH urchin-like nanostructures can be due to anisotropic structure and PEG-1000 selective adsorption. By annealing the preobtained InOOH precursor at 500 degrees C under ambient pressure, metastable hexagonal indium oxide (H-In2O3) urchin-like nanostructures, inheriting the morphology of its precursor in the transformation process, were obtained. The photocatalytic activity of as-prepared H-In2O3 was evaluated by photo de gradation of rhodamine B (RhB) dye under ultraviolet (UV) light illumination. The stability of the photocatalytic performance of H-In2O3 urchin-like nanostructures was investigated by circulating run tests in the photodegradation of RhB. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)