Rational design of TiO2 hollow nanospheres decorated with ultrathin g-C3N4 nanosheets for enhanced photocatalytic degradation of tetracycline

Herein, the mechanically exfoliated ultrathin g-C 3 N 4 nanosheets (NSs) are used to decorate TiO 2 hollow microspheres to obtain composite core–shell photocatalysts. The composite hollow microspheres are analyzed through PXRD, Raman spectroscopy, N 2 adsorption–desorption measurements, SEM, TEM, HRTEM, XPS, UV–Vis diffuse reflectance spectra, UPS measurements, PL spectra, photocurrent curves, and EIS spectra. The obtained results show that the composite microspheres have improved visible-light response and boosted carrier separation. Furthermore, the synthesized samples have excellent photodegradation performance for the antibiotic tetracycline and rhodamine B (RhB) under visible light, and the corresponding photodegradation rates are 94.5 and 96.5% at 60 min. In addition, the synthesized catalysts also maintain excellent stability in multiple cycles of experiments. Based on the experimental results, a possible photodegradation pathway on composite microspheres has also been proposed.