Chemical morphology freezing: chemical protection of the physical morphology of high photoactivity anatase TiO2nanotubes

Abstract

In this paper, an unavoidable thermodynamic behavior of nanomaterials is prevented by using a simple chemical morphology freezing method. Titanate nanotubes (no photoactivity) are filled with LaMer-model carbon and then coated with a silica sheath. This chemical filling and coating process ‘isolates’ micro-thermal deformation from the system, and consequently prevents the destruction of the tubular morphology during the calcination process. After calcination, novel high photoactivity TiO₂nanotubes are obtained with perfect open-ended tubular morphology and fine anatase phase. The sample shows the highest photoactivity of all the samples, which is 2 times higher than that of TiO₂nanorods, and is 4 times higher than TiO₂nanoparticles (P-25).