Oxygen-rich TiO2 decorated with C-Dots: Highly efficient visible-light-responsive photocatalysts in degradations of different contaminants

Abstract

Providing novel photocatalysts with high photocatalytic efficiency is of great significance. In the present work, hydrogen peroxide and carbon dots (C-Dots) were utilized to enhance the photocatalytic performance of TiO2 under visible light. The fabricated TiO2-peroxo/C-Dots photocatalysts were analyzed by XRD, HRTEM, SEM, EDX, BET, FT-IR, XPS, PL, UV–Vis DRS, EIS, and photocurrent density. Photocatalytic abilities of the nanocomposites were evaluated by photocatalytic removal of RhB, MO, MB, fuchsine, and Cr (VI) upon visible-light illumination. The results demonstrated that the binary nanocomposites exhibited remarkably enhanced photocatalytic activity compared with the TiO2 and TiO2-peroxo photocatalysts. The best photocatalytic performance was obtained using 0.75 mL of C-Dots, which was approximately 79.2, 17.1, 71.4, and 40.5 times higher than the pure TiO2 for degradations of RhB, MO, MB, and fuchsine, respectively. Furthermore, the TiO2-peroxo/C-Dots nanocomposites exhibited high stability in consecutive photocatalytic processes. Based on the results, the TiO2-peroxo/C-Dots photocatalyst is expected to become a promising photocatalyst for practical applications in water purification.