Multiple-cores@shell clustered carbon dots/P25/rGO nanocomposite as robust visible-light photocatalyst for organic pollutant degradation and water disinfection

Abstract

A novel photocatalyst was developed by combining TiO2 (P25), reduced graphene oxide (rGO), and multi-core@shell clustered carbon dots (CDs) by one-step hydrothermal method for the high efficiency visible-light degradation of organic dyes and antibacterial application. The as-synthesized CDs were used as photosensitizers of P25 to effectively broaden its visible absorption region from 410 to 800 nm. Meanwhile, the effects of different contents of CDs and rGO on the photocatalytic performance were systematically studied, in which 2% CDs/0.5% rGO/P25 composite displayed the most efficient photocatalytic degradation for organic dyes and photocatalytic antibacterial performance under visible light irradiation. The corresponding degradation rate constant of 2% CDs/0.5% rGO/P25 for RhB was 29, 2.8 and 1.3 times more than those of P25, rGO/P25, and CDs/P25 composite, respectively. This unique multi-core@shell clustered CDs played a vital role in improving the photocatalytic activity of the CDs/rGO/P25 composite, increasing visible light absorption, and promoting electron-hole pairs separation.