Should TiO2 nanostructures doped with Li+ be used as photoanodes for photoelectrochemical water splitting applications?

Abstract

[EN] Different TiO2 nanostructures, nanotubes and nanosponges, were obtained by anodization of Ti under stagnant and hydrodynamic conditions. Samples were doped with Li+ before and after annealing at 450 degrees C during 1 h. The nanostructures were characterized by different microscopy techniques: Field Emission Scanning Electron Microscopy (FE-SEM) and Raman Confocal Laser Microscopy. Additionally, Incident Photon-to-electron Conversion Efficiency (IPCE), photoelectrochemical water splitting and stability measurements were also performed. According to the results, TiO2 nanostructures doped before annealing present the worst photocurrent response, even if compared with undoped samples. On the other hand, this study reveals that Li+-doped TiO2 nanostructures doped after annealing can be used as durable and stable photoanodes for photoelectrochemical water splitting applications. (C) 2017 Elsevier Inc. All rights reserved.