Direct growth of hierarchical nanoneedle arrays with branched nanotubes from titanium foil with excellent anti-corrosion and superhydrophilicity

Abstract

We report a facile solution method to directly form dendritic titanium oxide (TiO2) nanostructures from titanium (Ti) substrates for realizing high specific surface areas with excellent crystallinity. We first form spiky nanoneedles on Ti substrates by using chemical solution etching, which are utilized as trunks. In addition, we employ a chemical exfoliation and rolling method to realize branched nanotubes over the spiky nanoneedles. Subsequent heat treatment leads to form TiO2 rutile crystal structures. The fabricated platform shows similar to 140 times higher specific surface areas than the planar surface, while exhibiting excellent anti-corrosive properties. As one of the potential applications, we demonstrate that the dendritic TiO2 surfaces have excellent surface wickability to exhibit significantly enhanced heat transfer characteristics in boiling process.