▎ 摘　　要

TiO2 as the most efficient advanced photocatalytic material has shown great potential for wastewater remedi-ation. However, its efficiency is restricted due to limited visible light harvesting and low separation of carrier pairs. Herein we report a positive effect of a new mononuclear eight-coordinated lanthanide metal complex, [Dy (DMPB)3(DMF)3(H2O)2] (CFU-2) as a photosensitizer to enhance both the solar-light response and charge sep-aration of TiO2. The prepared samples were characterized by XRD, BET, FT-IR, Raman, UV-Vis diffuse reflec-tance, cyclic voltammetry, and electrochemical impedance spectroscopy. Mott-Schottky plots were also used to investigate the band-edge potentials of the samples, which revealed a suitable LUMO energy level of CFU-2 for effective electron injection to the conduction band of TiO2. The optimized photocatalyst indicated an improved photocatalytic activity under visible light irradiation for photo-oxidation of atrazine (ATZ). The addition of 1.5 mM CFU-2 increased the rates of ATZ oxidation 32-fold higher than that of pure TiO2. Moreover, the deposition of the catalyst on the surface of reduced graphene oxide (RGO) provided a high surface area, and further reduced the rate of electron-hole recombination. In this architecture, CFU-2 and RGO acted as electron donor and electron acceptor, respectively. Accordingly, the synergistic effects of visible light harvesting of CFU-2, the intimate contact between the TiO2, RGO, and CFU-2, and the accelerated electron transfer led to the high photocatalytic performance of the CFU-2@TiO2/RGO.