Fabrication and gas sensitivity of SnO2 hierarchical 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 SnO2 films using a biotemplate eggshell membrane ( ESM) combined sol - gel approach. In order to promote the crystallization of SnO2 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, SnO2 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 SnO2 was measured for ethanol, liquefied petroleum gas (LPG), H2S, and gasoline. It is found that the SnO2 hierarchical films obtained have a good selectivity for LPG with a working temperature above 300 degrees C while for ethanol below 270.