Thickness-dependent layered BiOIO3 modified with carbon quantum dots for photodegradation of bisphenol A: Mechanism, pathways and DFT calculation

[Display omitted] •Thickness-dependent layered BiOIO3 modified CQDs was firstly synthesized.•Superiority of CQDs results from the improved charge transfer and separation.•High performance of BPA degradation (95.01 %) was achieved by 3 wt% CQDs/BiOIO3.•Mechanisms of enhanced BPA degradation by CQDs/BiOIO3 were deeply studied.•The degradation pathways were proposed based on DFT calculation and LC–MS analysis. Semiconductor photocatalysis has a great prospect in solving the problems of environmental pollution. Herein, the thickness-dependent BiOIO3 loaded by carbon quantum dots (CQDs/BiOIO3) was first synthesized. The 3 wt% CQDs/BiOIO3 with sheet-like morphology exhibited the highest efficiency of 95.01 % for the photodegradation of bisphenol A after 60 min. The outstanding photocatalytic activity was ascribed to two aspects: the first was the efficient separation of photogenic e−-h+ in thin layered BiOIO3 (50 nm); the second was the acceleration of charge transfer and the extension of light absorption after the CQDs co-catalysis. The h+ and O2− were dominant active species in the degradation process and possible mechanism was deeply studied. The attacked sites of bisphenol A were ascertained by Fukui index and the degradation pathways were proposed through the LC–MS analysis. This work significantly deepens the understanding of layered bismuth-based material and provides ideas for the design of high-performance catalysts.