Photocatalytic degradation of sulfonamides in suspensions of coral-like graphene carbon nitride with nitrogen vacancies.

Sulfonamides (SNs) belong to a category of broad-spectrum antibiotics, which have attracted growing concerns owing to the adverse effects on ecosystem. In this paper, coral-like graphitic carbon nitrides with nitrogen vacancies were prepared by polymerization of melamine in the presence of NHCl, and the effect of NHCl amount on the structure and photocatalytic performance of g-CN in degradation of sulfonamide antibiotics such as sulfamethoxazole (SMX), sulfadiazine (SDZ) and sulfathiazole (STZ) was systematically studied. It was found that the addition of NHCl results in the formation of coral-like g-CN with nitrogen vacancies, and optimal photocatalyst (PCN-1 sample) prepared with a melamine to NHCl mass ratio of 1:1 showed the highest photocatalytic activity towards SNs degradation due to the quick electron-hole migration, efficient separation capacity and excellent photoelectric properties.