Colloidal WO3 Nanowires as a Versatile Route to Prepare a Photoanode for Solar Water Splitting

This work describes a synthetic method to produce a WO3 nanowire as well as to prepare photoanodes by colloidal nanowire deposition. We also studied the influence of a nanowire phase on the photoanode performance for water splitting. Among the nanowires synthesized by using nonhydrolytic media, the orthorhombic WO3 center dot H2O nanowire produced a photoanode with excellent performance (a photocurrent of 1.96 mA?cm-2 at 1.23 VRHE) and good photocurrent stability during long-term analysis (chronoamperometry test). The structural and photoelectrochemical characterization showed the importance of nanostructural features such as exposed (200), (020), and (002) facets and porosity in the WO3 photoanode performance.