Synthesis of TiO 2 nanotube networks from the mineralization of swim bladder membrane in supercritical CO 2

Abstract

In this work, a green route to prepare TiO 2 nanotube networks using swim bladder (SB) membrane as a bio-template was reported. In this method, the SB membrane was first dried with CO 2 extraction, which resulted in the fibrous structures of SB membrane. With the CO 2-dried SB membrane as bio-template, TiO 2 were obtained via the surface sol–gel reaction of titanium isopropoxide on the fibers of SB membrane in supercritical CO 2, followed by the removal of SB membrane calcined at 600 °C. The resulting TiO 2 was characterized with scanning electron microscopy, transmission electron microscopy and X-ray diffraction. It was indicated that ordered anatase nanotube networks were produced. Compared to the conventional sol–gel method, the protocol adopted in this work could produce TiO 2 nanotubes with regular and ordered structures.