GREEN SYNTHESIS OF COPPER OXIDE NANOPARTICLES TO HARVEST THE LIGHT FOR PHOTOCATALYTIC DEGRADATION OF DYES METHYLENE BLUE AND METHYL ORANGE

Abstract

This research aims to explore the green synthesis approach and characterizations of copper oxide nanoparticles, which employed to photocatalytic degradation of direct dyes from aqueous solution. Centella asiatica fresh leaves were used in the green synthesis of copper oxide (CuO) nanoparticles (NPs) because it possess multifunctional properties like reducing agent as well as stabilizing agent. The copper oxide nanoparticles was synthesized at ambient temperature and pressure, furthermore it was characterized by scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA), which confirmed their thermal stability, and surface morphology. The photocatalytic efficacy of CuO was investigated against two common  dyes named as Methylene Blue (M.B) and Methylene Orange (M.O).Experiments were conducted  at room temperature under the batch condition with aid of Pyrex reactor where degradation efficiency were examined through  UV-Visible spectrophotometer. Analysis confirmed that, it was Pseudo first order degradation whereas activation energy calculated were  26.19 kJ/mol and 32.6 kJ/mol for M.O and M.B respectively. Factors such as initial concentrations of dye, temperature, does of catalyst, and rate of agitations were optimized to determine how these factors contribute the efficiency of degradation. The CuO nanoparticles showed excellent property as heterogeneous catalyst and retained same behaviour after multiple use. The results showed that the green synthesis of CuO NPs is promising due to inexpensive, greener process to decontaminate the dye-wastewater. This study explore the sustainable approach to synthesized green catalyst and addressing the removal of dye to mitigate the environmental remediation.