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 In3+ 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 °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 photodegradation 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.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) Urchin‐like nanostructured H‐In2O3, exhibiting good photocatalytic activity in the photodegradation of RhB, was prepared through annealing the InOOH precursor at 500 °C under ambient pressure.