Synthesis and optical properties of nanosheet-based rh-In2O3 microflowers by triethylene glycol-mediated solvothermal process

• Corundum nanosheet-based In2O3 microflowers were prepared.
• Phase transformation from InOOH to corundum In2O3.
• Strong photoluminescence emission.
• Triethylene glycol induced self-assembly and transformation process.

A new synthesis route for the construction of corundum nanosheet-based In2O3 microflowers is presented in this study. InOOH was firstly prepared by a solvothermal process using In(NO3)3·xH2O as a precursor, urea as a precipitant, and a mixture of triethylene glycol and water as the solvent at 200 °C for 18 h. The corundum nanosheet-based In2O3 microflowers were then obtained by calcining the obtained InOOH at 450 °C under ambient atmosphere. The products were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Raman and photoluminescence spectroscopy. The effects of solvent and urea on the fabrication of nanosheet-based corundum In2O3 microflowers were investigated and a self-assembly and transformation mechanism is proposed to explain the formation of the hierarchical nanostructures. The corundum nanosheet-based In2O3 microflowers show strong PL emission at 550 nm.