CuO decorated graphene TiO2 derived MIL-125 nanocomposite with enhanced photo-response as a highly efficient indirect sunlight driven photocatalyst

Abstract

Advanced Oxidation Processes (AOPs) are utilized to remove a large range of pollution in water by heterogeneous photocatalysis with production of electron-hole pairs by light. Herein, we showed the preparation of GO/MIL-125 by a simple solvothermal method and then the addition CuO by a simple wet impregnation method. MIL-125 and their derived have attracted considerable attraction due to high earth’s crust abundance, low toxicity, unique photo redox property and photocatalytic application. The photocatalyst, 5CuO/10GO/MIl-125 which was calcined at 600 ◦C (CuTG-600), with a bandgap of 2.82 eV, was utilized to degrade Rhodamine B (RhB) dye which is oxidized to CO2 and H2O. The characterization of different samples was investigated using FT-IR, XRD, XPS, SEM, EDX mapping, UV–vis spectroscopy, Linear sweep voltammetry, photocurrent response, electrochemical impedance spectroscopy (EIS) and Mott-Schottky plots. The combination of GO and CuO increases the degradation activity of RhB dye under irradiation of visible light (λ = 380–780), (blue LED lamp (λ = 450 nm) and red LED lamp (λ = 610 nm)) and the higher results were showed by 5CuTG-600. Photodegradation kinetics were explained by various parameters such as calcination, catalyst type, pH, dye concentration, catalyst dose, different lamps with different wavelengths, different scavengers and reusability. Furthermore, The Photoelectrochemical test results were noticed that the activity of 5CuTG-600 is higher than that of TG-600 and T-600 due to higher donor concentration (ND), and lower recombination process of the charge carrier. Finally, we obtain 5CuTG-600 which acts as an important photocatalyst and is used in environmental and electrochemical applications.