Architecture controlled synthesis of flower-like In2O3 nanobundles with significantly enhanced ultraviolet scattering and ethanol sensing

We have successfully synthesized novel needle-like and flower-like In2O3 nanobundles (NBs) composed of numerous parallel assembled nanoparticle chains via hydrolysis of InCl3 with NaBH4 in aqueous solution and subsequent heat treatment. These previously unknown nanostructures exhibit unusual optical and ethanol sensing properties. T-matrix simulation evidently explains the assembling effect on the significant scattering of UV-visible spectra including a characteristic peak in the UV region as well as the broadened edge toward the visible region for these two NBs. The greatly enhanced ethanol-sensing properties observed for the flower-like In2O3 NBs indicate that the dominant factors for sensing are not only the nanoparticle size but also the structural dimension and architecture of the nanoassembly.