(575ab) Nanoporous Gallium Oxides through Evaporation-Induced Self-Assembly

Mesostructured metal oxides are not only useful as catalysts and separating or adsorbing agents but also as functional host materials with unique optical, electrical, or magnetic properties, owing to the shape-specific and/or quantum effects of their thin inorganic skeletons. In particular, gallium oxide is a wide-band-gap semiconductor (Eg = 4.9 eV) that exhibits luminescence and conduction properties with potential applications in optoelectronic devices, high-temperature stable gas sensors and high- temperature/high-power electronic devices. Also, it has been used as a catalyst for the oxidative dehydrogenation of ethane to ethane and propane to propene.

Here, we report the synthesis and characterization of mesoporous gallium oxide via evaporation-induced self-assembly (EISA). The resulting Ga2O3 phases were characterized by BET, N2 adsorption-desorption isotherms, pore size distribution, SEM, XRD, FTIR, Raman, and TGA. The use of triblock co-polymers (P123 and F127) and charged templates (CTAB) as the structure directing agents led to the formation of mesoporous phases with BET surface area as high as 300 m2 g-1 and unimodal pore sizes in the 2 to 15 nm range. Hydrothermal treatment of the gels at 180-200oC and calcination at 320oC led to the formation of mesoporous gallium oxide spheres with an average size of 4-5 µm. The nitrogen adsorption-desorption isotherms indicated that these spheres show highly ordered mesoporous structure with the BET surface area of 100 m2 g-1 and uniform pore size in the range of 4-14 nm.

Keywords: Mesoporous Gallium Oxide, Ga2O3- spheres, EISA.

*Corresponding author: macarr15@louisville.edu