Enhancement of visible-light-driven O2 evolution from water oxidation on WO3 treated with hydrogen

•The photocatalytic O2 evolution activity of hydrogen-treated WO3 is enhanced more than twice compared to the pristine WO3.•Hydrogen treatment of WO3 generates a kind of HxWO3–WO3 composite on the surface layer of WO3.•The electrical conductive HxWO3 phase plays as a role of reduction cocatalyst for WO3.

The photocatalytic O2 evolution from water oxidation was investigated over a series of WO3 materials treated with hydrogen at different temperatures. The activity of WO3 treated with hydrogen at 200 °C can be enhanced to 2.3 times of that of pristine WO3. The surface WO3 layer is partially reduced during the hydrogen treatment, forming a kind of HxWO3–WO3 composite material. The HxWO3 phase possesses high electrical conductivity and plays as a reduction cocatalyst for WO3 in the photocatalytic process. Formation of suitable amount of HxWO3 could facilitate the transfer of electrons, leading to efficient charge separation of WO3 and resulting in the enhancement of the photocatalytic O2 evolution activity under visible light irradiation. Fabrication of semiconductor and conductor nanocomposite might be a useful strategy for the development of efficient water-splitting photocatalysts.

Graphical abstractFormation of suitable amount of metallic conductive HxWO3 on WO3 facilitates the transfer of electrons, leading to efficient charge separation and hence resulting in the enhancement of the photocatalytic O2 evolution activity under visible light irradiation.Figure optionsDownload full-size imageDownload high-quality image (58 K)Download as PowerPoint slide