Fabrication of Bi2WO6 photoelectrodes with enhanced photoelectrochemical and photocatalytic performance

• Published in: Solar energy materials and solar cells 2019-06, Vol.195, p.134-141
• Main Authors: Alfaifi, Bandar Y., Tahir, Asif A., Wijayantha, K.G. Upul
• Format: Article
• Language: English
• Subjects: Annealing; Bi2WO6; Bismuth compounds; Catalytic activity; Chemical properties; Correlation analysis; Crystallography; Density; Electrochemistry; Energy conversion; Exploitation; Fabrication; Light; Morphology; Nanoplate; Nanostructures; Optical properties; Organic chemistry; Photocatalysis; Photocatalyst; Photoelectric effect; Photoelectric emission; Photoelectrochemical; Photovoltaic cells; Potassium chloride; Pyrolysis; Rhodamine; Semiconductor materials; Silver chloride; Solar energy; Solar energy conversion; Spray pyrolysis; Thin films; Tungstates
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2019.02.031

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 °C has photocurrent density of 42 μAcm−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. •Cost-effective methodology for morphology and orientation-controlled deposition Bi2WO6 thin films for PEC and photocatalytic application.•Bi2WO6 Photoelectrodes with compact and porous morphology can easily be fabricated by choosing appropriate annealing temperature.•A systematic study has been conducted to show that the Bi2WO6 photoelectrodes have superior electrochemical and photocatalytic properties.•A very good correlation between morphology, crystallographic orientation and electrochemical and PEC performance is reported.•A strong correlation between photocatalytic dye degradation and fabrication parameters is established.