Fabrication and gas sensitivity of SnO₂hierarchical films with interwoven tubular conformation by a biotemplate-directed sol–gel technique

A facile and versatile method is reported to fabricate the interwoven tubular hierarchy of SnO 2 films using a biotemplate eggshell membrane (ESM) combined sol–gel approach. In order to promote the crystallization of SnO 2 films, calcination is necessary and can adjust the size of the building units in the range 2.8–26 nm. Under the direction of ESM biomacromolecules, SnO 2 nanocrystallites come into being and assemble into nanotubes, and further pattern porous hierarchical meshworks to faithfully retain the morphology of natural ESM. The sensor performance of as-prepared biomorphic SnO 2 was measured for ethanol, liquefied petroleum gas (LPG), H 2 S, and gasoline. It is found that the SnO 2 hierarchical films obtained have a good selectivity for LPG with a working temperature above 300 °C while for ethanol below 270 °C.