Water splitting on TiO 2 nanotube arrays

Abstract

TiO 2 nanotube arrays can be synthesized by several experimental procedures. Here we construct the first theoretical model of the array. Based on the density functional theory calculations, the formation energy of the TiO 2 nanotube array is nearly the same as that of rutile TiO 2 (1 1 0) surface. Moreover the electronic properties of TiO 2 nanotube arrays have been analyzed. The thermodynamic properties of H 2O splitting on the TiO 2 nanotube and nanotube arrays have been discussed using the density functional theory calculations and Gibbs free energy diagrams. The overpotential of H 2O splitting is 0.51 and 1.0 eV on the outside and inside of nanotube and 1.13 eV on the inside TiO 2 nanotube of an array.