Abstract: The preparation of In_2O_3 nano-powder used one-step hydrothermal method with PEG-600 as surfactant. Its size, phase and morphology were analyzed by XRD, SEM and TEM. The gas sensing characteristics of the materials were tested in static slate. The results show that the morphology of In_2O_3 is nanorods with good dispersity. The average length of the as-synthesized nanorods reaches about 150 nm, and the width about 20 nm, giving an aspect ratio of a few hundreds. It has a high sensitivity as high as 32.2 to 10 ppm NO_2 at lower working temperature 125 ℃. The sensor based on In_2O_3 also has satisfactory selectivity, quickly response and recover times.

Key words: In_2O_3%surfactant%hydrothermal method%gas sensing characteristics