Bioinspired synthesis of continuous titania coat with tunable nanofiber-based network structure on linear polyethylenimine-covered substrates.

We report using the substrates covered with self-organized linear polyethylenimine (PEI) layer as biomimetic template to direct the formation of high-quality titania coat with well-defined nanofiber-based network structure. The titania deposition was simply achieved by dipping the PEI substrates into aqueous solution of titanium bislactate under ambient conditions. We found that crystalline PEI layer on the substrates is important for achieving titania coat with nanofiber-based structure. Compared to the titania powder formed by solution deposition, the interface-mediated nanostructured titania exhibited dramatically improved thermostability with being able to maintain anatase phase in majority even at 900 degrees C. Moreover, the nanostructures of titania coat could be well controlled by simply adjusting the formation conditions of crystalline PEI layer on substrates. Because of high-efficiency photocatalysis of anatase titania, the nanostructured surface exhibited good photoresponsive surface wettability through hydrophobic modification and light irradiation.