Photocatalytic water splitting for O2 production under visible-light irradiation on BiVO4 nanoparticles in different sacrificial reagent solutions

Monoclinic BiVO4 nanoparticles were prepared through a homogeneous co-precipitation process. The products calcined at different temperatures were characterized by X-ray diffraction, transmission electron microscopy and UV–vis diffused reflectance spectroscopy. The photocatalytic O2 evolution efficiencies over the BiVO4 nanoparticles under visible-light (λ > 420 nm) irradiation were also investigated comparatively by using AgNO3 and Fe(NO3)3 as sacrificial reagents. Experimental results indicate that AgNO3 is a more effective sacrificial reagent for the photocatalytic O2 evolution over BiVO4 than Fe(NO3)3 due to the efficient separation of the photogenerated electron–hole pairs at the Ag/BiVO4 interfaces, but the BiVO4/Fe(NO3)3 system is more promising in the aspect of practical applications due to its more steady photoactivity and more convenient reactivation of the photocatalyst.

The as-synthesized BiVO4-HCP forms spherical particles with an average particle size of 30.8 nm. The inserted selected area electron diffraction patterns (SAED) show a defined hexagonal spot pattern, suggesting the single crystal nature of the as-synthesized BiVO4-HCP. So the BiVO4-HCP powders can be used as excellent photocatalysts due to crystal interfaces of single crystal particles.Figure optionsDownload as PowerPoint slide