Green Synthesis of TiO2/CuO Nanocomposites using Rosa Abyssinica Leaf Extract for Photocatalytic Degradation of MB Dye Under Visible Light Source

Abstract

This research focuses on the photocatalytic properties of synthesized titanium dioxide and copper oxide nanocomposites (TiO2/CuO NCs). The synthesis of these TiO2/CuO NCs was conducted using a sustainable and environmentally friendly green method that involves the utilization of a leaf extract from an Ethiopian endemic plant known as Rosa Abyssinia. This green plant-templated approach embraces the advantages of utilizing readily available natural resources, underscoring the importance of green chemistry in contemporary research. To evaluate the structural and optical characteristics of the synthesized nanomaterials, a series of characterization techniques were employed. These included X-ray diffraction (XRD), which provided insights into the crystal structure and phase purity of the synthesized materials; UV–visible diffuse reflectance spectroscopy (UV-Vis-DRS), which was used to assess the light absorption properties; Fourier transform infrared (FT-IR) spectroscopy, which helped in identifying the functional groups present; and photoluminescence (PL) measurements, which offered information about electronic transitions within the materials. From UV-Vis-DRS analysis the estimated energy band gaps were found to be 2.31 eV for theTiO2/CuO(2:1) composition, 2.65 eV for TiO2/CuO(1:1) , and 2.75 eV for TiO2/CuO (1:2). The FTIR analysis also revealed the presence of TiO2 and CuO in the the green synthesized nanocomposites. The PL study showed that TiO2/CuO (1:1). The photocatalytic activity of the synthesized nanomaterials was rigorously investigated using methylene blue (MB) dye as a model pollutant. Among the various compositions studied, the TiO2/CuO nanocomposite in a 1:1 ratio exhibited the most promising photocatalytic performance for the degradation of methylene blue under light irradiation. Several parameters were scrutinized, including the pH of the dye solution, the amount of catalyst used, and the initial concentration of the dye. The results indicated that optimal degradation efficiency was achieved at a pH level of 10, a catalyst loading of 20 mg, and an initial dye concentration of 15 ppm. These findings underscore the potential of using synthesized TiO2/CuO NCs as efficient photocatalysts for the degradation of organic pollutants, contributing to the advancement of sustainable water treatment technologies.