Synthesis and characterization of single-crystalline Bi2O2SiO3 nanosheets with exposed {001} facets

Abstract

Bismuth oxide silicate (Bi₂O₂SiO₃) single-crystalline nanosheets with exposed {001} facets were synthesized for the first time via a facile one-step CTAB-assisted hydrothermal method in the presence of NaOH. Control experiments were carried out to investigate various factors that affect the formation, morphology and exposed planes of the products systematically. The results revealed that the pH and the amount of CTAB play vital roles in the reaction. Bi₂O₂SiO₃ nanosheets could not be obtained without the addition of sodium hydroxide solution in the synthesis process, and CTAB not only promotes the exposure of {001} facets, but also modulates the size and thickness of these Bi₂O₂SiO₃ nanosheets in a wide range. It was shown that the as-prepared Bi₂O₂SiO₃ nanosheets synthesized under the conditions that the amount of CTAB was 4 mmol and the pH value was 12 exhibited higher photocatalytic activities toward RhB and BPA degradation under simulated sunlight irradiation than all the other samples in our experiment, which might give the main credit to the highly exposed {001} facets and considerable number of oxygen vacancies. The present work provides a new reference for the synthesis of Bi₂O₂SiO₃ nanosheets and other manipulation of facet-dependent photoreactivity of semiconductors.