High-performance porous spherical or octapod-like single-crystalline BiVO4 photocatalysts for the removal of phenol and methylene blue under visible-light illumination

Monoclinic BiVO4 single-crystallites with a polyhedral, spherical or porous octapod-like morphology were selectively prepared using the triblock copolymer P123 (HO(CH2CH2O)(20)(CH2CH(CH3)O)(70) (CH2CH2O)(20)H)-assisted hydrothermal method with bismuth nitrate and ammonium metavanadate as metal source and various bases as pH adjustor. The BiVO4 materials were well characterized and their photocatalytic activities were evaluated for the removal of methylene blue (MB) and phenol in the presence of a small amount of H2O2 under visible-light illumination. It is shown that the pH value of the precursor solution, surfactant, and hydrothermal temperature had an important impact on particle architecture of the BiVO4 product. The introduction of P123 favored the generation of BiVO4 with porous structures. The BiVO4 derived hydrothermally with P123 at pH 3 or 6 possessed good optical absorption performance both in UV- and visible-light regions and hence showed excellent photocatalytic activities for the degradation of MB and phenol. It is concluded that the high visible-light-driven catalytic performance of the porous octapod-like BiVO4 single-crystallites is associated with the higher surface area, porous structure, lower band gap energy, and unique particle morphology. Such porous BiVO4 materials are useful in the solar-light-driven photocatalytic treatment of organic-containing wastewater. (C) 2012 Elsevier B.V. All rights reserved.