Efficient Photoelectrochemical Water Splitting by Anodically Grown WO₃Electrodes

Abstract

The potentiostatic anodization of metallic tungsten has been investigated in different solvent/electrolyte compositions with the aim of improving the water oxidation ability of the tungsten oxide layer. In the NMF/H(2)O/NH(4)F solvent mixture, the anodization leads to highly efficient WO(3) photoanodes, which, combining spectral sensitivity, an electrochemically active surface, and improved charge-transfer kinetics, outperform, under simulated solar illumination, most of the reported nanocrystalline substrates produced by anodization in aqueous electrolytes and by sol-gel methods. The use of such electrodes results in high water electrolysis yields of between 70 and 90% in 1 M H(2)SO(4) under a potential bias of 1 V versus SCE and close to 100% in the presence of methanol.

A theoretical analysis of optical absorption limits and performance of tandem devices and series interconnected architectures for solar hydrogen production

“…Semiconductors that have been investigated rather thoroughly as photoelectrodes for one of the halfreactions include, for example, Fe 2 O 3 [29][30][31], TiO 2 [32,33], WO 3 [34,35], BiVO 4 [36,37], ZnO [38,39], and Cu 2 O [40,41]. An underlying implicit argument is that if the investigated material shows promise for one of the half-reactions, it should in principle be possible, in a later stage, to combine it with another material into a device for the overall water splitting reaction.…”

Enhancing photoelectrochemical activity of nanocrystalline WO3 electrodes by surface tuning with Fe(Ⅲ)

“…A large number of approaches have been taken to improve the PEC performance of WO 3 photoelectrodes. Several preparing methods like solegels [13], hydrothermal [14], sputtering [15] and electrochemical anodization [16] were selected. Heterojunction films have been extensively investigated, such as WO 3 /Fe 2 O 3 [17], WO 3 /BiVO 4 [18], WO 3 /Cu 2 O [19] and WO 3 /TiO 2 [20].…”

On the electrochemical synthesis and charge storage properties of WO3/polyaniline hybrid nanostructures

“…Anodization is a well-known method for preparing transition metal oxides [4,17] with effective control over the morphology of the produced nanostructures (pore size [18], layer thickness [19][20][21], and structural features [22,23]). Furthermore, it circumvents the use of binding agents, as the nanostructured metal oxide is directly grown from the respective metal foil.…”