| In2O3 is an important transparent semiconductor with a wide band gap (3.5-3.7eV), which has been applied in many areas such as solar cells, photocatalyst and gas sensors. It is well known that In2O3 has two phases: cubic In2O3 (C-In2O3) and hexagonal In2O3 (H-In2O3). In this work, InOOH and In(OH)3 were fabricated through a simple hydrothermal method at different hydrothermal temperatures and volume ratios of En and H2O. C-In2O3 and H-In2O3 were obtained by annealing these two precursors at 400℃in air, respectively. The gas sensing properties of the obtained materials were measured to compare the discrepancies between them. The following is the main contents in this work:1. Indium oxide nanomaterials with different phase structures were fabricated through hydrothermal (solvothermal) method. The effect of initial temperature on the morphology of precursor was studied and the possible mechanism of the formation was also proposed. The results indicated that higher hydrothermal temperature or smaller water in the system were prone to generate InOOH and the low initial temperature would lead to the formation of In(OH)3 microsphere as a result of En acting as a template. Moreover, the phase transition between In(OH)3 and InOOH only occurred in the stage of hydrothermal synthesis.2. In2O3 was synthesized via solvothermal process using DEG or DMF as solvents by one step. The effects of reaction conditions on phase structures and morphologies were studied. The results indicated that a little water was prefer to generate In2O3 in DEG but would impede the formation of In2O3 in DMF.3. The gas sensing properties of the obtained materials toward acetone and ethanol were measured to determine the optimum working temperatures of the as-prepared materials and compare the discrepancies between them. It was found that space charge layer and oxygen vacancies played crucial roles in determining the responses of the gas sensors. |
PDF Full Text Request