Eco-Friendly Synthesis of CuO–Supported Carbon Nanocomposites for Rapid Catalytic Degradation of Methylene Blue

Abstract

Copper oxide (CuO) nanoparticles were successfully synthesized via a green synthesis route using Vitex negundo Linn leaf extract as a reducing and stabilizing agent. The synthesized nano-CuO was impregnated onto carbon material derived from the stem of Chromolaena odorata to obtain CuO–carbon (CuO–C) nanocomposites. The prepared materials exhibited excellent catalytic performance in the degradation of methylene blue (MB) dye at room temperature. Various concentrations of CuO–C were investigated to optimize the CuO loading for maximum degradation efficiency. The characteristic absorption peaks of MB at 244 nm, 291 nm, and 663 nm disappeared completely after treatment with the CuO–C composite, confirming the effective degradation of the dye. The 5% CuO–C nanocomposite material showed the highest degradation efficiency, attributed to the synergistic interaction between CuO nanoparticles and the carbon support, which enhanced charge transfer and reduced recombination. Additionally, the effect of thermal activation at 50 °C was examined, revealing temperature-dependent catalytic behavior. The adopted synthesis approach is simple, eco-friendly, and cost-effective, demonstrating the potential of CuO–C   nanocomposites as efficient catalysts for the removal of organic dyes from wastewater.