Recent advance on engineering titanium dioxide nanotubes for photochemical and photoelectrochemical water splitting

Abstract

Photochemical and photoelectrochemical water splitting is both an attainable and sustainable strategy for generating environmentally friendly energy sources. One-dimensional (1-D) TiO2 nanotubes is a promising photochemical/photoelectrochemical material due to the general availability, low-cost, chemical stability, large surface-volume ratio and straight electron transfer pathway. In this paper, we present recent progress on hydrogen evolution through water splitting by using 1-D titanium dioxide nanotubes (TNTs) as photoelectrode materials. The basic principles behind the technology of photochemical water splitting are discussed, such as light absorption, suppressing charge recombination, modifying redox potential as well as increasing stability, followed by engineering consideration and design of the 1-D TiO2 nanotube photo-anodes. The links between photochemical properties of nanostructured TiO2 and H2 conversion are discussed. Meanwhile, rationally orienting the nanostructured TiO2 in chemical reactors for hydrogen conversion and engineering prospects are highlighted for potential development.