Novel two-dimensional Bi4V2O11 nanosheets: controllable synthesis, characterization and insight into the band structure

In this work, a stable EDTA-Bi complex formed by the chelation of bismuth ions and ethylenediaminetetraacetic acid (EDTA) under alkaline conditions was adopted to controllably prepare novel two-dimensional (2D) Bi4V2O11 nanosheets via a facile hydrothermal method. It is proved that the phases of the product will change with the variation of the amount of EDTA and the pH value of the precursor solution. The fabricated Bi4V2O11 has a uniform sheet-like structure with a thickness of 1.26 nm. Based on the experimental results, we provide a reasonable nucleation and growth mechanism for Bi4V2O11 nanosheets, which could give some suggestions on the synthesis of other 2D Bi-based materials. On the basis of Mott-Schottky plots and UV-vis diffuse reflectance spectra, we demonstrate that the as-obtained Bi4V2O11 is an n-type semiconductor and possesses a better light-harvesting ability in comparison with monoclinic BiVO4. In addition, the corresponding conduction band potential and valence band potential of the Bi4V2O11 nanosheets are ascertained as well.