Enhanced visible-light photocatalytic activities of porous olive-shaped sulfur-doped BiVO4-supported cobalt oxides

Porous S-doped bismuth vanadate with an olive-like morphology and its supported cobalt oxide (y wt% CoOx/BiVO4−δS0.08, y = 0.1, 0.8, and 1.6) photocatalysts were fabricated using the dodecylamine-assisted alcohol-hydrothermal and incipient wetness impregnation methods, respectively. It is shown that the y wt% CoOx/BiVO4−δS0.08 photocatalysts were single-phase with a monoclinic scheetlite structure, a porous olive-like morphology, a surface area of 8.8–9.2 m2/g, and a bandgap energy of 2.38–2.41 eV. There was the co-presence of surface Bi5+, Bi3+, V5+, V3+, Co3+, and Co2+ species in y wt% CoOx/BiVO4−δS0.08. The 0.8 wt% CoOx/BiVO4−δS0.08 sample performed the best for methylene blue degradation under visible-light illumination. The photocatalytic mechanism was also discussed. We believe that the sulfur and CoOx co-doping, higher oxygen adspecies concentration, and lower bandgap energy were responsible for the excellent visible-light-driven catalytic activity of 0.8 wt% CoOx/BiVO4−δS0.08.

The good photocatalytic performance of 0.8 wt% CoOx/BiVO4−δS0.08 for methylene blue degradation is ascribed to the S- and CoOx-doping, high Oads content, and low bandgap energy.Figure optionsDownload as PowerPoint slideHighlights
► Porous S-doped BiVO4-supported CoOx are prepared by the impregnation method.
► 0.8 wt% CoOx/BiVO4−δS0.08 possesses the highest surface oxygen species concentration.
► 0.8 wt% CoOx/BiVO4−δS0.08 possesses the lower bandgap energy.
► 0.8 wt% CoOx/BiVO4−δS0.08 performs the best for methylene blue photodegradation.
► S- and CoOx-doping, Oads content, and bandgap energy govern photocatalytic activity.