Effect of proton intercalation on photo-activity of \WO3\ anodes for water splitting
By Sonia J. Calero and Pablo Ortiz and Andr
Published in International Journal of Hydrogen Energy
2016
Abstract
Porous and nanostructured \WO3\ semiconductor thin films have been used as electrodes for water photo-electrolysis. As water-splitting cells frequently operate in acidic conditions, the aim of this work is to evaluate the effect of proton intercalation of \WO3\ electrodes on the performance of the photo-electrolysis process. For this, a first study of proton charge and proton discharge electrode's capacity was performed under cathodic and anodic polarization, respectively, at different voltages and times. Protonated electrodes were then exposed to simulated solar radiation in a photo-electrochemical cell (PEC) and characterized with both chronoamperometry and linear sweep voltammetry. The results indicated that proton intercalation reduces \WO3\ photo-activity; however, the effect is reversible and after enough time full proton discharge is achieved and photoresponse is recovered. The work points out the influence of the \WO3\ film microstructure on the discharge kinetics and proposes proton intercalation/deintercalation studies as a characterization technique of photoelectrodes.