Enhanced solar-induced photocatalytic removal of antibiotics over molecularly reconstituted graphitic carbon nitride

Promoting the photocatalytic performance of graphitic carbon nitride (g-C3N4) for efficient removal of organic contaminants like antibiotics from wastewater has gained much consideration due to its metal-free uniqueness and environmental friendliness. In this work, the photocatalytic activity of g-C3N4 is greatly enhanced via a hydrothermally molecular dissociation and subsequent calcination reconstitution, which endows g-C3N4 with a large specific surface area, rapid separation of photogenerated electron/holes and strong redox ability. The apparent kinetic constant (k) of tetracycline hydrochloride (TCH) for the sample obtained under the optimal preparation conditions (CN-C-12) is 4.5 times that of pristine g-C3N4, companied with a stable cycling photo -catalytic activity. The possible degradation pathways and the toxicological evaluation of the intermediates were analyzed by LC-MS and ECOSAR. Superoxide radicals (& BULL;O2-) and singlet oxygen (1O2) are detected to be the primary reactive species in the photocatalytic degradation of TCH. Additionally, the practical application of CN-C-12 for TCH removal in actual sunlight and treatment of domestic printing and dyeing wastewater was also investigated. This work shows a potential application of the molecular reconstituted g-C3N4 in the photo -catalytically environmental purification.

Automated summary

The photocatalytic performance of g-C3N4 for the removal of antibiotics from wastewater can be enhanced by hydrothermal dissociation and subsequent calcination reconstitution, resulting in a higher specific surface area, efficient charge separation, and strong redox ability. The optimized sample (CN-C-12) shows a 4.5 times higher apparent kinetic constant (k) for tetracycline hydrochloride (TCH) degradation compared to pristine g-C3N4, with stable cycling photo-catalytic activity. Superoxide radicals (& BULL;O2-) and singlet oxygen (1O2) are identified as the primary reactive species in the photocatalytic degradation of TCH.