ABSTRACT
The removal of pollutants from water bodies is crucial for the well-being of humanity and is a topic of global research. Researchers have turned their attention to green synthesized nanoparticles for wastewater treatment due to their eco-friendly nature, biocompatibility, and cost-effectiveness. This work demonstrates the efficient removal of organic dye and both gram-positive and gram-negative bacteria from water bodies using copper-doped cerium oxide nanoparticles synthesized withMurraya Koenigiiextract. Characterized via various methods, the 15% copper doped cerium oxide nanoparticles (Cu 15% NPs) exhibited maximum Congo red dye adsorption (98% degradation in 35 min). Kinetic analysis favoured a pseudo-second-order model, indicating the chemical nature of adsorption. Equilibrium adsorption isotherms aligned with the Langmuir model, indicating homogenous monolayer dye adsorption on the doped adsorbent. The maximum uptake of adsorbate,Qmobtained from Langmuir model for Cu 15% NPs was 193 mg g-1. The study also showed enhanced antibacterial activity againstBacillus subtilis, Staphylococcus aureus, Escherichia coliandPseudomonas aeruginosafor Cu-doped ceria, attributed to generation of reactive oxygen species (ROS) induced by the redox cycling between Ce3+and Ce4+. This substantiated that the green synthesized copper doped cerium oxide nanoparticles are potential candidates for adsorptive removal of Congo red dye and as antibacterial agents.