Difunctional carbon quantum dots/g-C3N4 with in-plane electron buffer for intense tetracycline degradation under visible light: Tight adsorption and smooth electron transfer

In this study, a lateral heterostructures material (LCCN) of carbon quantum dot (CQDs) and carbon nitride (CN) was designed via the thermal polymerization of freeze-dried precursor. The special lateral heterostructures (LHSs) increased the bond length of O-O to fleetly active dissolved oxygen (DO), which exhibits 14-fold increased for tetracycline (TC) visible-light degradation compared to CN. In addition, the electrons of activated DO came from both TC and LCCN, which trapped the oxygen to generate multitudinous superoxide radical (center dot O-2(-)), while the hole (h(+)) showed a negligible role in photocatalytic system. A rapid electron transfer channel was speculated between TC and photocatalyst by experiments and density functional theory. Furthermore, DFT and LC/MS predicted four degradation pathways of TC with the Fukui index (f(0)), and LCCN exhibited a favorable hinder on various environmental interferences. This work presented a novel perspective for the relationship of pollutant and material in photocatalysis.

Automated summary

This study designed a lateral heterostructures material of carbon quantum dot and carbon nitride, which effectively increased the activation of dissolved oxygen and visible-light degradation of tetracycline. Experimentally and theoretically, a rapid electron transfer channel was confirmed between tetracycline and photocatalyst, and various degradation pathways were predicted with favorable hinder on environmental interferences.