In₂O₃ Hollow Microspheres:  Synthesis from Designed In(OH)₃ Precursors and Applications in Gas Sensors and Photocatalysis

Abstract

In this work, well-shaped In(OH)3 hollow microspheres have been successfully prepared via a novel surfactant-free vesicle-template-interface route in the "formamide-resorcinol-water" system, in which spontaneous vesicles were formed under hydrothermal conditions and NH3 from the hydrolysis of formamide acted as the OH- provider. Morphological and structural characterizations indicate that the shells of as-prepared In(OH)3 hollow microspheres were constructed by numerous nanocubes about 80 nm in size. As desired, In2O3 hollow microspheres were obtained from annealing the designed In(OH)3 precursors, and the as-obtained In2O3 hollow microspheres performed well as a gas-sensing material in response to both ethanol and formaldehyde gases and as a photocatalyst for photocatalytic degradation of rhodamine B. The facile preparation method and the improved properties derived from special microstructures are significant in the synthesis and future applications of functional nanomaterials.

Indium hydroxide nanocubes and microcubes obtained by microwave-assisted hydrothermal method

“…In recent years, In(OH) 3 nanostructures with different morphologies such as cubes [2,3], flowers [4], truncated polyhedral microcrystals [5], spheres [6], etc., have been synthesized by several synthesis methods. The physical and chemical properties of these nano-or micron-sized powders can be influenced by shape, size and size distribution of the particles which depend on the synthesis method.…”

“…The physical and chemical properties of these nano-or micron-sized powders can be influenced by shape, size and size distribution of the particles which depend on the synthesis method. The hydrothermal synthesis has been used to obtain nanostructures and the microstructure of indium hydroxide using a method which is simple, practical and environmental friendly [6].…”

Use of nanotechnology for clean and safer future environment

“…β-Ga 2 O 3 has various technological applications, such as transparent conducting oxides, optical emitters for ultraviolet radiation, flat-panel displays, spin tunneling junctions, and high temperature gas sensing [2][3]. Fig.1 Indium oxide (In 2 O 3 ) is a wide band-gap transparent semiconductor (direct band gap of 3.55 − 3.75 eV and indirect bandgap of 2.6 eV), which can be widely used in electronic and optoelectronic devices, flat panel displays, gas sensors, and photocatalysis [7][8][9]. Different nanostructures of In 2 O 3 like nanowire, nano-belt, nanocolumn, nano-octahedra were reported.…”

Research Advances in Photocatalysis of Inorganic Hollow Spheres

“…Manjula et al [52] utilize glucose as structure-directing agent to prepare porous tin oxide hollow spheres, which not only can photodegrade dye but also can be reused. The indium oxide hollow spheres gained by Li et al [53] using emulsion vesicles as templates can photodecompose Rh B under ultraviolet light irradiation.…”