One-step hydrothermal synthesis of hierarchical nanosheet-assembled Bi2O2CO3 microflowers with a {001} dominant facet and their superior photocatalytic performance

Abstract

Using citric acid (CA) and 1,5-naphthalenedisulfonic acid (NDSA) as the structure-directing agent, a hierarchical flower-like Bi2O2CO3 product is successfully prepared via a simple one-step hydrothermal synthesis, which is spirally assembled by the {001} facet-dominated nanosheets. It is testified that the additive CA plays an important inducing role in forming the chemical composition of Bi2O2CO3, the nanosized sheet-type subunits, and the exposure of the {001} facet, while the NDSA greatly improves the dispersity and porous structure of the Bi2O2CO3 microflower. Due to the nano-size effect and distortion of surface Bi-O bonds, the Bi2O2CO3 microflower could be excited by the visible light to exhibit a superior photocatalytic performance in the degradation of tetracycline (TC). Besides, it is found the exposed {001} facet of Bi2O2CO3 would preferentially generate holes during the illumination process, thus enhancing the photooxidative activity of the Bi2O2CO3 microflower. Finally, the structural and optical features of the Bi2O2CO3 microflower have been discussed in detail, and its photocatalytic mechanism has also been proposed in this work.