Template‐Free Synthesis of Electroconductive Triphenylamine–Silica Nanotubes Exhibiting a Mixed‐Valence State

The self‐assembly and polycondensation of a triphenylamine‐derived organosilane precursor in an aqueous mixture result in electroactive organosilica nanotubes without the use of template materials. The nanotubes are easily synthesized by the slow addition of water to an acidified organic solution of the precursor, followed by basification with an aqueous NaOH solution. In contrast to conventional sol–gel methods that yield amorphous organosilica materials, the present organosilica nanotubes exhibit birefringence due to the orientation of the triphenylamine moieties within the tube walls. The template‐free formation of nanotubes with optical anisotropy suggests a roll‐up mechanism of 2D nanosheets consisting of hydrolyzed precursors. The organosilica nanotubes contain a high density of oriented triphenylamine moieties, and exhibit a mixed‐valence state with a near‐infrared absorption band due to chemical doping along with high electrical conductivities, on the order of 10 −3 –10 −2 S cm −1 . Such nanostructured organosilicas, comprising an electroactive framework, are useful for optoelectronic and photocatalytic applications.