Synthesis of In2O3 nanocrystals with metal catalyst nanoparticles attached for enhanced chemical sensing

In2O3 with wide band gap (3.6 eV) and visible light transparency is a very important n-type semiconductive material, which is being extensively investigated in various fields such as solar cells, UV laser, window heaters, flat panel display, gas sensors, etc. In our previous work, In2O3 nanocrystals were synthesized by thermal decomposition of metal-organic precursors and assembled into thin film devices for chemical sensing applications. Noble metal catalysts were also sputtered on the surface of the thin film devices to increase their sensitivity. In this work, one-step chemical synthesis was used to attach noble metal catalyst nanoparticles, such as Pt, Au, etc., directly onto the surface of the In2O3 nanocrystals first, and then assemble into the thin films for chemical sensor studies. The noble metal coated nanocrystals were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDS), UV-Vis absorption and fourier transform infrared spectroscopy (FTIR). The sensing performance for different chemicals will also be discussed