Highly Efficient Degradation toward Tylosin in the Aqueous Solution by Carbon Spheres/g-C3N4 Composites under Simulated Sunlight Irradiation

Carbon spheres (CS) were synthesized from monosaccharides (glucose), disaccharides (beta-cyclodextrin), and polysaccharides (sucrose) using surfactants, and then by hydrothermal treatment with g-C3N4 to form composites. The photodegradation efficiency of tylosin (TYL) by modified carbon spheres/g-C3N4 composite materials was investigated. The results illustrated that the efficiency of photo degradation of TYL by modified carbon spheres/g-C3N4 composites is higher than that of pure carbon spheres and g-C3N4. Furthermore, the surface characteristics and microstructures of the as-prepared composite materials were analyzed by different means. The results demonstrated that a small amount of carbon spheres embedded in g-C3N4 can form the heterojunction with an intimate interface, which boosts the absorption scope of visible light, enlarges surface areas, and facilitates the segregation of electron hole pairs of g-C3N4. Free radical quenching experiments showed that the main active groups of TYL photodegradation were the superoxide radical (center dot O-2(-)) and hydroxyl radical (center dot OH).