Preparation of mesoporous In2O3 nanorods via a hydrothermal-annealing method and their gas sensing properties

In this work, we report the simple solid-state formation of mesoporous In2O3 nanorods with a quasi-single-crystalline framework. The synthesis is based on controlled thermal oxidative decomposition and re-crystallization of precursor In(OH)3 nanorods obtained from a hydrothermal method without using any surfactants or organic templates. Importantly, the rod-like morphology can be completely preserved after thermal treatment. Due to the intrinsic crystal contraction, a highly mesoporous structure with high specific surface area (up to 103.1 m2/g) has been created. The textual properties can be tailored by varying the annealing temperature. The gas sensing test results show that mesoporous In2O3 nanorods possess satisfactory response to dilute ethanol vapor.