Metastable Hexagonal In₂O₃ Nanofibers Templated from InOOH Nanofibers under Ambient Pressure

Abstract

Single‐crystal, metastable, hexagonal In2O3 (H‐In2O3) nanofibers with an average diameter of 80 nm and length of up to several micrometers were synthesized on a large scale, for the first time under ambient pressure, by annealing InOOH nanofibers at 490 °C. The InOOH nanofibers were prepared by a controlled hydrolysis solvothermal reaction, using InCl3·4H2O as the starting material and ether as the solvent, in the temperature range of 190–240 °C. The solvent has significant effects on the formation of the metastable phase and the morphology of the In2O3 nanocrystals during the synthesis of the precursor InOOH. Room‐temperature optical absorption spectra of the hexagonal In2O3 nanofibers showed strong absorption peak located at 325 nm (3.83 eV) with a slight blue‐shift compared with that of bulk In2O3 (3.75 eV). The H‐In2O3 nanofibers photoluminesce at room temperature with emission peaks at 378 nm, 398 nm, and 420 nm. The successful production of metastable hexagonal In2O3 nanofibers in large scale under mild conditions could be of interest both for applications and fundamental studies.

Pbca-Type In2O3: The High-Pressure Post-Corundum phase at Room Temperature.

“…167, Z=6) which was obtained after application of extreme conditions of pressure and temperature. [10][11][12] The synthesis of corundum-type In 2 O 3 at room conditions [13][14][15][16][17][18] has allowed the characterization of its properties for its use in industrial applications; [19][20][21] therefore, the discovery of new phases of this compound is of fundamental and technological interest.…”

Synthesis, characterization and gas sensing properties of flowerlike In2O3 composed of microrods

“…Recently, the synthesis of nanostructured In 2 O 3 compounds have attracted special attention in fundamental study, such as nanorods [1], nanowires [18,19], nanofibers [20,21], nanotubes [22,23], nanobelts [24,25], nanocubes [26][27][28], and nanoparticles [29][30][31]. Meanwhile, it is necessary to synthesize ordered threedimensional (3D) structured In 2 O 3 nanocomposite/microcomposite for the development of a nanodevice/microdevice with high performance in gas-sensing.…”

Controllable synthesis of novel In2O3 nanostructures and their field emission properties

“…However, the In 2 O 3 nanowhiskers exhibited a red-shifted emission peak positioned at 592 nm in comparison with In 2 O 3 nanorods and nanoflowers. The different emission peaks can be originated from the varied energy levels yielded by oxygen vancancies [28]. Field emission properties of the In 2 O 3 nanorods, nanoflowers, and nanowhiskers were measured, and the dependencies of the field emission current density on the applied electric field (J-E) are shown in figure 5.…”