Solution-Based Comproportionation Reaction for Facile Synthesis of Black TiO<sub>2</sub> Nanotubes and Nanoparticles
Zebiao Li, Haidong Bian, Zhengtao Xu, Jian Lü, Yang Yang Li
Abstract
A convenient and efficient strategy is disclosed for blackening anodic TiO2 nanotubes and commercial P25 powders through an easy solution-soaking treatment at mild conditions (e.g., 60 °C) in polyol (e.g., glycerol, ethylene glycol) solutions. The F– ions, acidic polyol solvents, and contact between the TiO2 and Ti components are discovered to be the prerequisites for the water-promoted comproportionation between TiO2 and Ti, which generate Ti(III) species that effectively blacken different TiO2 nanomaterials, including the anodic nanotube arrays and P25 nanoparticles. The black TiO2 thus obtained from this convenient soaking method displays improved photoelectrochemical performance.