Effect of sulfur doping on the photocatalytic performance of BiVO4 under visible light illumination

Porous monoclinic bismuth vanadate (BiVO4−δ) and sulfur-doped bismuth vanadates (BiVO4−δS0.05, BiVO4−δS0.08, and BiVO4−δS0.12) were synthesized by a dodecylamine-assisted alcohol-hydrothermal route in the absence and presence of thiourea or Na2S. The physicochemical properties of the materials were characterized and their photocatalytic performance for the degradation of methylene blue and formaldehyde under visible light was evaluated. The samples have a single phase monoclinic scheetlite crystal structure with a porous olive-like morphology, surface areas of 8.4–12.5 m2/g, and bandgap energies of 2.40–2.48 eV. Surface Bi5+, Bi3+, V5+, and V4+ species were present on the S-doped BiVO4−δ samples. Sulfur doping influenced the surface Bi5+/Bi3+, V5+/V4+, and Oads/Olatt molar ratios, and the amount of sulfur doped had an important effect on the photocatalytic performance. Under visible light, BiVO4−δS0.08 performed the best in the photodegradation of methylene blue and formaldehyde. A higher surface oxygen species concentration and a lower bandgap energy were responsible for the excellent visible light photocatalytic performance of BiVO4−δS0.08.

Graphical AbstractPorous BiVO4−δ and BiVO4−δSσ are fabricated using dodecylamine-assisted alcohol-hydrothermal strategy. The higher Oads concentration and lower bandgap energy account for excellent photocatalytic performance of BiVO4−δS0.08 for methylene blue and formaldehyde degradation.Figure optionsDownload full-size imageDownload as PowerPoint slide