Synthesis of 42-faceted bismuth vanadate microcrystals for enhanced photocatalytic activity

Bismuth vanadate (BiVO4) microcrystals enclosed with up to 42 low and high index facets were synthesized through truncation of BiVO4 octahedral crystals via a simple and highly reproducible hydrothermal method. The size and shape of the truncated BiVO4 crystals could be tuned by varying the acid concentration, reaction temperature and reaction period. Compared to the BiVO4 octahedral crystals without truncation, the 42-faceted ones showed an enhanced photocatalytic activity in the degradation of rhodamine B molecules due to the enhanced charge separation on the exposed low and high index facets. This was confirmed at sub-particle level by the photo-deposition of gold and manganese oxide nanopartides selectively on hot electron and hole accumulated facets, respectively. Our results will provide a guideline for the synthesis of more efficient BiVO4 and many other multinary metal oxide-based photocatalysts. Moreover, the synthesized microcrystals are perfect materials for the study of photocatalytic property of BiVO4 at single and sub-particle level. (C) 2019 Elsevier Inc. All rights reserved.