Fabrication of Bi2WO6 photoelectrodes with enhanced photoelectrochemical and photocatalytic performance

Visible light active semiconductor Bi2WO6 photoelectrodes with desired physical and chemical properties are sought for solar energy conversion and photocatalytic applications. The porous nanostructured Bi2WO6 photoelectrodes are prepared by Spray Pyrolysis (SP). A detail study has been conducted to correlate the annealing temperature, morphology and crystallographic orientation with the photoelectrochemical (PEC), electrochemical and photocatalytic properties. The photoelectrodes possess an optical bandgap of 2.82 eV and exhibit anodic photocurrent. The current-voltage characterization of Bi2WO6 photoelectrodes reveals that the photocurrent density and photocurrent onset potential is strongly dependent on the deposition parameters. The PEC study shows that the photoelectrode annealed at 525 degrees C has photocurrent density of 42 mu Acm(-2) at 0.23 V (vs Ag/AgCl/3M KCl) under AM1.5 illumination and exhibit superior photocatalytic activity for Rhodamine B (RhB) degradation. The electrochemical study shows that the photoelectrode has flatband potential of 2.85 V which is in good agreement with photocurrent onset potential. This finding will have a significant influence on further exploitation of Bi2WO6 as a potential semiconductor material in solar energy conversion and photocatalytic applications.