Nanotube array-like Wo3/W photoanode fabricated by electrochemical anodization for photoelectrocatalytic overall water splitting

Photoactive WO3 is attractive as a photocatalyst for green energy evolution through water splitting. In the present work, an electrochemical anodic oxidation method was used to fabricate a photo -responsive nanotube array-like WO3/W (NA-WO3/W) photoanode from W foil as a precursor. Compared with a reference commercial WO3/W electrode, the NA-WO3/W photoanode exhibited enhanced and stable photoelectrocatalytic (PEC) activity for visible-light-driven water splitting with a typical Hz/Oz stoichiometric ratio of 2:1 and quantum efficiency of approximately 5.23% under visible-light irradiation from a light-emitting diode (A = 420 nm, 15 mW/cm(2)). The greatly enhanced PEC performance of the NA-WO3/Wphotoanode was attributed to its fast electron-hole separation rate, which resulted from the one-dimensional nanotube array-like structure, high crystallinity of monoclinic WO3, and strong interaction between WO3 and W foil. This work paves the way to a facile route to prepare highly active photoelectrodes for solar light transfer to chemical energy. (c) 2017, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.