Designing of WO3@Co3O4 Heterostructures to Enhance Photoelectrochemical Performances.

ABSTRACT

Heterostructured photocatalysts are superior to single photocatalysts because they offer better charge separation and broaden light harnessing abilities. Although WO3 is considered an oxygen-evolving photocatalyst with decent stability and proper band gap, its lower photocatalytic efficiency is ascribed to high charge recombination. In this research, a WO3@Co3O4 heterostructure reduced the recombination of photocatalytic charges and extended light absorption abilities, resulting in improved photocatalytic activity. The presence of Co3O4 nanoparticles improved light absorption and charge transfer of tungsten oxide films for photoelectrochemical reactions. For photoelectrochemical water oxidation, WO3@Co3O4 nanostructures generated a photocurrent 20 times higher than that of pure WO3. Both electrodeposition and sol gel techniques were utilized to synthesize the WO3@Co3O4 photoelectrode. Scanning electron microscopy and X-ray diffraction were used to characterize the formation of the above photocatalyst. A photocurrent study was done to investigate the charge separation mechanism to explain the enhanced photocatalytic activity.