Mesoporous assembled SnO2 nanospheres: Controlled synthesis, structural analysis and ethanol sensing investigation

A series of mesoporous SnO2 nanospheres were prepared in ethanol/water mixed solvents with pore-forming surfactant (CTAB) involved. Surprisingly, the nanospheres assembled from SnO2 nanocones exhibited higher sensitivity to ethanol than hollow and amorphous-core counterparts, and more importantly, such submicrometer-sized spheres all showed linear responses to external ethanol concentration, similar to those extremely small spheres. Careful structure characterizations revealed their inner structure and crystallization behavior differences. It was finally concluded that the growth model difference significantly affected the inner structures (or assembly fashions) of these nanospheres, and consequently determined their sensing performances.