Graphitic Carbon Nitride with Carbon Vacancies for Photocatalytic Degradation of Bisphenol A

Abstract

Photocatalysis is intensely employed to remove refractory organic pollutants in water but suffers from low efficiency due to the rapid recombination of photogenerated electrons and holes. Here, carbon-vacancy-modified g-C3N4 (VC-C3N4) is prepared via a handy two-step calcination method and first applied in the photocatalytic removal of bisphenol A (BPA). Compared to pristine g-C3N4, the photocatalytic degradation activity of VC-C3N4 for BPA is largely enhanced, in which the kinetic constant (k) of BPA degradation is 1.65 times that of pristine g-C3N4. The enhanced photocatalytic performance of VC-C3N4 is ascribed to the critical role of carbon vacancies. On the one hand, carbon vacancies serve as the reservoir of photogenerated electrons to inhibit the recombination of photogenerated holes and electrons. On the other hand, carbon vacancies as conversion centers transfer trapped photogenerated electrons to absorbed O2 for the generation of an abundant superoxide radical (•O2–), which takes a dominant effect in the photocatalytic degradation process.