Fabricating metal-free Z-scheme heterostructures with nitrogen-deficient carbon nitride for fast photocatalytic removal of acetaminophen

Photocatalytic technology has been increasing explored for the elimination of pollutants from aquatic envi-ronments. However, constructing powerful photocatalyst to drive rapid decontamination remains challenging. Here, we assemble boron-doped nitrogen-deficient carbon nitride (BNCN) into metal-free Z-scheme hetero-junction via a facile approach to boost photocatalytic degradation of acetaminophen. Incorporating boron dopants and nitrogen defects to C3N4 significantly increase the photoabsorption. Furthermore, the constructed heterojunction exhibited decreased band gap and remarkably enhanced separation efficiency of photogenerated carriers compared with individual BNCN. Owing to the modulation of band structures and the better separation of photogenerated carriers, acetaminophen conversion approaching 100 % was achieved in just 30 mins under simulated sunlight, outperforming equivalent quantities of bulk carbon nitride and commercial TiO2 by 3.1 and 2.7 times, respectively. Two possible photodegradation pathways were proposed with hydroxylation and ring-opening reactions as dominant degradation reactions. Our findings provide an instructive catalyst design strat-egy to boost photocatalytic degradation efficiency.