In2O3 nanocubes derived from monodisperse InOOH nanocubes: synthesis and applications in gas sensors

Monodisperse InOOH nanocubes have been synthesized by a facile two-phased solvothermal method via In(NO3)(3)center dot 4H(2)O and sodium oleate as the starting materials. Subsequently, the InOOH nanocubes were coated on an alumina ceramic tube and aged at 300 A degrees C for 3 days for the next gas sensing test. The XRD analysis illustrated that InOOH nanocubes had an orthorhombic phase structure consistent with the JCPDS cards number 73-1592. The XPS spectrum indicated that In and O exist on the surface of InOOH, and no impurity peaks were observed. The TEM results indicated that the InOOH are highly monodisperse nanocubes, with a mean size of 15 nm. After aging, cubic and hexagonal-coexisting In2O3 (JCPDS card number 88-2160 and card number 73-1809) were obtained, while the original cube shape was maintained. The gas response of the In2O3 was tested to several representative organic gases, and it displayed outstanding gas sensing performance toward ethanol, acetic acid, and ethyl acetate. Typically to 1000 ppm ethyl acetate vapor at 300 A degrees C, the response is R (a)/R (g) = 207.8. The results provide a facile route to prepare monodisperse nanoparticles for high-performance gas sensor.