Size-controlled conformal nanofabrication of biotemplated three-dimensional TiO2 and ZnO nanonetworks

A solvent-free fabrication of TiO₂ and ZnO nanonetworks is demonstrated by using supramolecular nanotemplates with high coating conformity, uniformity, and atomic scale size control. Deposition of TiO₂ and ZnO on three-dimensional nanofibrous network template is accomplished. Ultrafine control over nanotube diameter allows robust and systematic evaluation of the electrochemical properties of TiO₂ and ZnO nanonetworks in terms of size-function relationship. We observe hypsochromic shift in UV absorbance maxima correlated with decrease in wall thickness of the nanotubes. Photocatalytic activities of anatase TiO₂ and hexagonal wurtzite ZnO nanonetworks are found to be dependent on both the wall thickness and total surface area per unit of mass. Wall thickness has effect on photoexcitation properties of both TiO₂ and ZnO due to band gap energies and total surface area per unit of mass. The present work is a successful example that concentrates on nanofabrication of intact three-dimensional semiconductor nanonetworks with controlled band gap energies.