Preparation of effective magnetic graphene quantum dot nanocomposite for tetracycline absorption

Graphene quantum dots (GQDs) are a zero-dimensional carbon-based nanomaterial with excellent photoluminescent properties, stability, and ease of fabrication [۱]. GQDs synthesized by hydrothermal methods are highly soluble in water, which limits their use as catalysts and absorption materials. To solve this problem, various researchers have fabricated magnetic GQDs, but most of their methods were multistep and required stabilizing and reducing agents [۲]. In this work, we prepared a magnetic sulfur/nitrogen graphene quantum dots by one-pot hydrothermal synthesis without a reducing agent or stabilizing agent and used them as a novel photocatalyst for the removal and photodegradation of the antibiotic tetracycline (TC). Therefore, our magnetic nanocomposite was synthesized in one-pot procedure by the hydrothermal method by adding Fe۳+ to the S,N-GQD solution under alkaline condition without adding stabilizer and reducing agent. Effective parameters on tetracycline (TC) removal such as pH, initial TC concentration, and contact time were tested [۳]. pH is one of the most important parameters affecting the photodegradation capacity of antibiotics such as TC in water media (Fig. ۱). The results showed that the lowest TC removal rate is related to pH ۷ (about ۴۴%), and when pH decreases from ۹ to ۴, TC degradation efficiency increases from ۷۳% to ۸۱% after ۶۰ minutes, respectively.

کلیدواژه ها:

Magnetic nanocomposite ، Graphene quantum dots ، Tetracycline ، Photocatalysis ، Degradation efficiency.