Fabrication of carbon quantum dot-decorated Bi2MoO6 composites via a hydrothermal method for enhanced photocatalytic degradation of Rhodamine B

Bi 2 MoO 6 , a Bi-based semiconductor catalyst, exhibits effective degradation of organic pollutants. Nevertheless, its photocatalytic performance is constrained by several limitations, such as inadequate sunlight absorption, poor charge mobility, and fast charge carrier recombination upon photoexcitation. In this research, we successfully synthesized a Bi 2 MoO 6 composite modified with carbon quantum dots (CQDs), which demonstrates a significant improvement in photocatalytic performance. A series of characterizations and photocatalytic experiments were performed on the synthesized CQDs/Bi 2 MoO 6 samples. Degradation experiments revealed that under simulated sunlight, the CQDs/Bi 2 MoO 6 composite achieved a 95 % degradation rate for Rhodamine B (RhB) within 70 min, with a kinetic constant of 0.03994 min −1 . In comparison, the undoped Bi 2 MoO 6 sample degraded only 46 % of RhB under the same conditions, exhibiting a kinetic constant of 0.00658 min −1 . The primary reactive species, ·O 2 − and h + , were unequivocally identified through combined ESR spectroscopy and radical scavenging experiments as the drivers of pollutant degradation. Furthermore, after four consecutive reaction cycles, the catalyst maintained 90.05 % of its initial activity, confirming its high stability. In summary, this study successfully developed a CQDs-doped Bi 2 MoO 6 composite photocatalyst, offering a promising strategy for advancing photocatalysis research.