Morphology Engineering of BiVO with CoO Derived from Cobalt-containing Polyoxometalate as Co-catalyst for Oxygen Evolution.

Bismuth vanadate (BiVO ) as a metal oxidation semiconductor has stimulated extensive attention in the photocatalytic water splitting field. However, the poor transport ability and easy recombination of charge carriers limit photocatalytic water oxidation activity of pure BiVO . Herein, the photocatalytic activity of BiVO is enhanced via adjusting its morphology and combination co-catalyst. First, the Cu-BiVO was synthesized by copper doping to control the growth of {110} facet of BiVO , which is regarded for the separation of photo-generated charge carriers. Then the CoO in-situ generated from K [SiCo (H O)W O ] ⋅ 16H O was photo-deposited on Cu-BiVO surface as co-catalyst to speed up reaction kinetics. Cu-BiVO @CoO hybrid catalyst shows highest photocatalytic activity and best stability among all the prepared catalysts. Oxygen evolution is about 34.6 μmol in pH 4 acetic acid buffer under 420 nm LED irradiation, which is nearly 20 times higher than that of pure BiVO . Apparent quantum efficiency (AQE) in 1 h and O yield are 1.83% and 23.1%, respectively. O evolution amount nearly maintains the original value even after 5 cycles.