EMIN Saim University of Nova Gorica

Water Splitting Activity of Textured WO3 Thin Films Prepared from Colloidal W Nanoparticles

Co-authors RESPINIS de Moreno, FANETTI Mattia, SMITH Wilson, VALANT Matjaz, DAM Bernard
Collaboration: Delft University of Technology, Delft, The Netherlands, EU

Colloidal tungsten (W) nanoparticles were synthesized by pyrolysis of W(CO)6 precursor in a mixture of oleylamine, oleic acid and octadecene at ~230 °C under Ar atmosphere. After extraction of the W nanoparticles from the reaction medium they were dissolved in CHCl3. The metallic W nanoparticles were spin-coated on fluorine doped tin oxide (FTO) substrates and later were transformed to WO3 by heat treatment at >500 °C. By using the present approach we prepared textured WO3 thin films with different thicknesses ranging from 200 to 900 nm. The obtained textured WO3 thin films were used for photoelectrochemical water splitting. The highest achieved photocurrent density recorded under illumination (1.5 AM, 100 mW/cm2) in 0.1 M Na2SO4 is in the order of 0.33 mA/cm2 at 1.4 V vs. Ag/AgCl. The proposed route is an unexplored way for fabrication of textured WO3 thin films. This procedure can be also extended for the preparation of other metal oxides like Fe2O3, MoO3, Cr3O4 or NiO thin films.