Photocatalytic water splitting has been explored extensively as a promising way to capture and store solar energy. In this study, stable WO3 thin-film photoelectrodes for water splitting applications were prepared with the simple, inexpensive, and scalable technique of electrostatic spray deposition. The physicochemical, structural, optical, and morphological properties of the WO3 films were studied with X-ray diffraction, Raman spectroscopy, UV-visible spectroscopy, and scanning electron microscopy. The thickness of the films prepared was varied from 50 to 400 nm in order to establish a relationship between film thickness and water splitting performance. The photocurrent of the WO3 thin films, measured in a 0.5 M Na2SO4 electrolyte solution against a standard Ag/AgCl reference electrode, increased with increasing film thickness. The film electrosprayed for 10 min exhibited a photocurrent density of 0.04 mA/cm2. The photocurrent density was increased by 10-fold to 0.40 mA/cm2 when the electrospraying time was increased to 60 min. Of all the films tested in this study, the film electrosprayed for 60 min, which had a thickness of 400 nm, showed the best photoelectrochemical cell activity.
Bibliographical noteFunding Information:
This research was supported by Global Frontier Program through the Global Frontier Hybrid Interface Materials (GFHIM) of the National Research Foundation of Korea ( NRF ) funded by the Ministry of Science, ICT & Future Planning ( 2013M3A6B1078879 ). This work was also supported by NRF-2013R1A2A2A05005589 and by the Industrial Strategic Technology Development Program ( 10045221 ) funded by the Ministry of Knowledge Economy (MKE, Korea). The authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding the work through the research group project No. RGP-089.
- Tungsten oxide
- Water splitting
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