High-aspect-ratio single-crystalline porous In₂O₃ nanobelts with enhanced gas sensing properties

With greatly enhanced surface-to-volume ratios, one-dimensional (1-D) nanostructures are believed to be able to deliver better performance as chemical sensors. In this paper, by using a hydrothermal-annealing process, we reported the synthesis of porous In₂O₃ nanobelts with a high aspect ratio. By annealing hydrothermally-synthesized single crystalline ultralong InOOH nanobelts, single crystalline porous In₂O₃ nanobelts with an aspect ratio larger than 100 are obtained on a large scale. The gas sensing properties of the as-prepared porous In₂O₃ nanobelts were investigated, and they can detect different chemicals (methanol, ethanol, and acetone) down to ppb level. The results also showed that the nanobelts exhibited excellent gas sensing performance in terms of high sensitivity, low detection limit, fast response and recovery times, and sensing selectivity.