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

Herein, the mechanically exfoliated ultrathin g-C3N4 nanosheets (NSs) are used to decorate TiO2 hollow microspheres to obtain composite core–shell photocatalysts. The composite hollow microspheres are analyzed through PXRD, Raman spectroscopy, N2 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.