Synthesis of carbon quantum dots/TiO2 nanocomposite for photo-degradation of Rhodamine B and cefradine

Pure TiO2 and carbon quantum dots (CQDs)-doped TiO2 nanocomposite (CQDs/TiO2 nanocomposite) were prepared by a sol-gel approach for photocatalytic removal of Rhodamine B and cefradine. Analyses by Transmission electronmicroscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), UV visible spectroscopy and X-ray powder diffraction (XRD) confirmed the successful formation of CQDs/TiO2 heterostructure. The as-prepared TiO2 and CQDs/TiO2 composite possessed small particles, spherical-like shape, and anatase crystal form. Meanwhile, Rhodamine B and cefradine were chosen to evaluate the photocatalytic activity of TiO2 and CQDs/TiO2 composite. Results revealed that with the facile decoration of CQDs, the absorption of photocatalyst was extended into visible light region and photocatalytic activity was improved in comparison with pure TiO2. Furthermore, the mechanism for the improvement of the photocatalytic performance of the composites was discussed on the basis of the results. CQDs play an important role in the photocatalytic process, due to their superior ability to extend the visible absorption and produce more electrons and electron-hole pairs for the degradation of pollutants. In all, the paper offers further insights into the development of CQDs/TiO2 nanocomposite as photocatalyst for the degradation of antibiotics. (C) 2016 Elsevier B.V. All rights reserved.