Novel F-modification of g-C3N4/ZnAl–LDHs binary heterojunction with notable 2D/2D configuration for efficient visible-light-driven photocatalytic elimination of organic pollutants

In this work, we prepared a novel binary heterojunction comprising ZnAl–LDHs and F-modified g-C₃N₄ (FCN) with a notable 2D/2D configuration via a facile hydrothermal method. The visible-light-driven FCN/ZnAl–LDHs (FCN/LDHs) binary heterojunctions exhibited superior increased photocatalytic performance towards the removal of tetracycline (TC, antibiotics) contaminant, which is far better than that observed for pristine FCN and LDHs. Moreover, the addition of F atoms strikingly narrowed the bandgap energy and increased the separation rate of the photogenerated charge carrier of pristine g-C₃N₄, further enhancing the degradation efficiency of TC under different environmental conditions. Particularly, the FCN/LDHs binary heterojunctions with the optimized doping contents (30 mg) of FCN exhibited the best photodegradation activity among all the synthesized samples. And it also showed significant stability and reusability according to recycling experiments due to the intimate interfacial contact between FCN and LDHs promoted via their precise 2D/2D arrangement. Results of trapping experiments and band energy analysis obviously illustrate that superoxide radical and hole are the auxiliary active species increasing TC photodegradation, and further, the plausible photocatalytic mechanism for TC degradation over FCN/LDHs are proposed.