Inorganic-Salt-Assisted Morphological Evolution and Visible-Light-Driven Photocatalytic Performance of Bi2WO6 Nanostructures

Recently, the controlled synthesis of semiconductor photocatalysts has attracted intense attention. In this report, we first report the controlled synthesis of Bi2WO6 nanostructures via the soluble inorganic salt Na2SO4-assisted hydrothermal method by simply adjusting the reaction time and pH value. Four typical Bi2WO6 nanostructures were obtained, namely nestlike nanostructures assembled by nanoplates (NNS-ANPs), rodlike nanostructures assembled by nanoplates (RNS-ANPs), quantum dots-modified nanoplates (QDs-NPs), and smooth-surfaced nanoplates (SSNPs). Tentative formation mechanisms of the different morphologies based on our observations are discussed. Photocatalytic degradation results show that the degradation ratios (DRs) of three-dimensional structures are higher than those of two-dimensional structures, and surface QDs play key roles in enhancing the DR of QDs-NPs. Morphology-dependent photocatalytic activities of different Bi2WO6 nanostructures are possibly due to different charge-separation abilities, which has been demonstrated by photoluminescence analyses.