Hydrothermal synthesis of porous In2O3 nanospheres with superior ethanol sensing properties

Porous In2O3 nanospheres were synthesized by calcining the precipitates prepared through a facile one-step hydrothermal synthesis method. Techniques of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), transmission electron microscope (TEM), and N2 adsorption–desorption analyses were used to characterize the structure and morphology of the products. The as-synthesized porous In2O3 nanospheres were composed of numerous tiny In2O3 nanoparticles and possess good size uniformity and large specific surface area. On the basis of experimental results, a possible mechanism for the formation of porous In2O3 nanospheres was speculated. Moreover, gas sensing investigation showed that the sensor based on porous In2O3 nanospheres exhibited higher response to ethanol gas compared with that of commercial bulk In2O3 particles. The enhancement in gas sensing properties was attributed to their unique structure, large surface areas, and more surface active sites.