We demonstrate that the addition of a tungsten oxide (WO<inf>3</inf>) layer beneath a bismuth vanadate (BiVO<inf>4</inf>) photocatalyst layer with a nanotextured pillar morphology significantly increases the photocurrent density in photoelectrochemical water splitting. The WO<inf>3</inf>-BiVO<inf>4</inf> bilayer films produced a photocurrent of up to 3.3 mA/cm<sup>2</sup> under illumination at 100 mW/cm<sup>2</sup> (AM1.5 spectrum). The bilayer film was characterized by scanning electron microscopy, X-ray diffraction, and photoelectrochemical methods, which confirmed the superiority of the bilayer film in terms of its morphology and charge separation and transport ability. Both WO<inf>3</inf> and BiVO<inf>4</inf> were deposited by electrostatic spraying under open-air conditions, which resulted in nanotextured pillars of BiVO<inf>4</inf> atop a smooth WO<inf>3</inf> film. The optimal coating conditions are also reported.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)