Ultrasound assisted synthesis of Bi2NbO5F/rectorite composite and its photocatalytic mechanism insights.

Enhancing the adsorbability of the photocatalysts is an effective way to improve the photocatalytic performance. Herein, we firstly synthesized a novel Bi2NbO5F/rectorite (BF/R) composite photocatalyst with high adsorption capacity via the ultrasound assisted route. The X-ray photoelectron spectrometer (XPS) analysis has demonstrated that the Bi2NbO5F and rectorite were connected with each other by weak chemical bonds. The introduced rectorite in the composite provided rich adsorption active sites for the adsorption of rhodamine B (RhB). The catalytic activity of the BF/R catalyst was evaluated by degrading RhB (5 mg/L) under UV-light irradiation. The BF/R composite with 32% rectorite exhibited the best photocatalytic degradation efficiency for degrading RhB in aqueous solution, which was 6.6 times higher than that of the bare BF sample. The improved activity of the BF/R composite can be ascribed to its strong adsorbability and enhanced light absorption. More importantly, the BF/R catalyst still showed good stability and high activity for degrading RhB after four recycles. Lastly, a possible photocatalytic mechanism on the BF/R composite was proposed. This work would provide helpful insights into the synthesis of the clay combined with Bi-based adjustable structure materials via ultrasound method.