Pd-nanoparticle-decorated peanut-shaped BiVO4 with improved visible light-driven photocatalytic activity comparable to that of TiO2 under UV light

Porous, peanut-shaped BiVO4 was prepared and further decorated with palladium nanoparticles on its surface using a photodeposition approach. The well-dispersed palladium nanoparticles were found to suppress photogenerated charge carriers, and may also improve the capacity of BiVO4 to harvest visible light photons due to a local surface plasmon resonance effect. The prepared Pd-BiVO4 composites exhibited excellent photocatalytic activity in the degradation of phenol under visible light irradiation. This performance rivaled that of TiO2 under UV light. However, the active oxidants in Pd-BiVO4 and TiO2 processes are different, with photogenerated holes in BiVO4 photocatalysis and OH radicals in TiO2 photocatalysis. Furthermore, different mechanisms and different pathways for the degradation of phenol under the effects of different oxidants were proposed. This work not only opens up new possibilities for the efficient removal of phenolic compounds in wastewater via visible-light-driven photocatalysis in the presence of a Pd-BiVO4 composite, but also suggests that OH radicals may not be the most important oxidants in all photocatalysis processes. (C) 2017 Elsevier Inc. All rights reserved.