Carbon quantum dots/ Cu2O S-scheme heterojunction for enhanced photocatalytic degradation of tetracycline

In this work, carbon quantum dots (CQDs) with yellow fluorescence were firstly prepared by hydrothermal method using corn stover as raw material. Then, the CQDs/Cu2O S-scheme heterojunction was obtained by combining the prepared CQDs with dodecahedral Cu2O. The catalytic performance of the prepared catalyst under visible light was studied by using tetracycline (TC) as the degradation target. The results showed that the conductivity and the active sites in Cu2O were enhanced by loading CQDs, and the 3 wt% CQDs/Cu2O heterojunction showed the highest photocatalytic performance and the most excellent stability with 92.49% of TC degradation within 100 min. It is found that the recombination rate of electron and hole was reduced by the CQDs/Cu2O heterojunction with improved separation efficiency of the photo-generated electron-hole pairs and enhanced photo-degradation efficiency.