Impacting Value of Different Oxidation States of Copper and Jamun Leaves Extract During the Green Synthesis of CuO Nanostructures for Efficient Photocatalytic Degradation of Methylene Blue in Aqueous Solutions

CuO-based photocatalytic materials were developed for the degradation of methylene blue (MB) in aqueous solutions, emphasizing two important aspects. First, it is necessary to consider the role different oxidation states of copper, derived from copper salts such as cupric chloride and cupreous chloride, play in nanostructured materials, particularly metal oxides. The second aspect is the use of Jamun leaves extract as a source of phytochemicals that are capable of reducing, capping, structuring, and stabilizing CuO nanostructures. CuO was prepared using chemical precipitation methods under mild hydrothermal conditions in both aspects. The shape structure, crystalline structure, surface functional groups, and optical properties of the material were studied using various analytical techniques. Copper ions are found to have significant effects on the size, shape, and crystalline properties of CuO based on their oxidation states. A preliminary photocatalytic study revealed that CuO nanostructures derived from cupric chloride were highly effective in decomposing MB in aqueous solutions under natural sunlight illumination. As part of the evaluation of CuO nanostructures, dye concentrations, pH effects, cycling stability, and scavenger tests were carried out. Through the analysis of the UV-visible absorption spectrum of MB at different time intervals, we were able to derive a pseudo first order model, degradation rate, and dye removal percentage. Using a fixed dose of 10 mg of CuO nanostructures synthesized from cupric chloride and Jamun leaves extract in alkaline pH 12 conditions, dye removal is found to be 100, restively after a short period. Furthermore, the recycling stability of CuO was also determined to be satisfactory, thus confirming its suitability for the long-term treatment of wastewater. According to the results of the proposed study, Jamun leaves extract and different oxidation states of the same metal ion can be used to develop high performance photocatalytic materials that can be utilized for environmental and energy applications.