Ultra-sensitive SnO2 gas sensors based on hierarchical octahedra

The controlled hydrolysis of Sn¹¹ precursor ([Sn(NMe)2]2) yields micrometric Sn3O2(OH)2 octahedra, formed by a self-assembly process. The water content and alkylamine surfactants are major parameters for the growth process. These structures have been employed to prepare highly sensitive gas sensors, which present 7% variation of their resistance at only 0.25 ppm CO.