Efficient Photodegradation of Rhodamine B and Tetracycline over Robust and Green g-C3N4 Nanostructures: Supramolecular Design

Abstract

Highly condensed g-C₃N₄ nanosheets with an exceptional surface area and porous structure were simply prepared by thermal condensation of stable preorganized supramolecular structures of cyanuric acid and melamine formed in water as the solvent. Different techniques were employed for the characterization of the structural, morphological, electrical, and optical features of the as-synthesized catalyst. All the characterizations confirmed the successful formation of nanosheets with magnificent properties compared to the pristine sample which was prepared by melamine polycondensation. Not only did these nanosheets exhibit a superb photocatalytic activity over the degradation of tetracycline (over 60%) and rhodamine B (100%) under visible light irradiation just for 15 min, but they also could maintain their stability during the reaction keeping over 98% of their original degradation even in 5 cycles. Superoxide anion radicals and holes were determined to be the main active species by trapping experiments. LC-Mass analysis was also performed to identify the intermediates and propose the possible pathway for photodegradation of tetracycline. The promising performance of this catalyst can be a notable step forward for prosperous industrial applications in the field of photodegradation of hazardous and not-easily degradable organic compounds in wastewater treatment plants.

Keywords: CM-complex; Photocatalysis; Rhodamine B; Tetracycline; degradation pathway.