Biogenic synthesis of tubular SnO2 with hierarchical intertextures by an aqueous technique involving glycoprotein.

Tetragonal SnO2 with hierarchical interwoven structures was prepared by a convenient soaking technique followed by a calcination treatment over 823 K. On the basis of the biomaterial eggshell membrane (ESM) being immersed in aqueous Sn colloid medium and a calcination treatment in succession, SnO2 nanocrystallites with a size of about 5 nm were formed, assembled into tubular fibers, and further intertwisted to construct hollow interconnective fibrous meshworks. With the biomaterial ESM serving as the physical substrate, chemical revulsant, and capping agent, the formation and assembly of hierarchical SnO2 nanomaterials should be under the control of glycoprotein contained in the ESM fiber mantle and directed by the interactions between the glycoprotein macromolecules (containing carboxyl, hydroxyl, and amino groups, etc.) and Sn colloid ingredients of the Sn impregnant. The unique hierarchical SnO2 nanomaterials of structural particularity and complexity are expected to find potential applications in gas sensors, photocatalysts, and dye-sensitized solar cells, etc.