<p>In the current study, micro composites based on copper manganese oxides were created using citric acid as a fuel through the auto combustion method. This study investigates the impact of Ce-doping on the optical, structural, and electrical properties of CuMn₂O₄. We demonstrate that Ce-doping can be a practical way to circumvent this limitation. Our study attempts to provide an explanation for the reduction in grain size and Ce content in the CuMn₂O₄ host material. The attenuated total reflectance spectra place the Ce in octahedral and tetrahedral locations. The plasmonic pure and Ce-doping CuMn₂O₄’s capacity to capture visible light and swiftly transfer photogenerated electrons is responsible for this enhanced performance. The results also demonstrated that as the Ce concentration of the dopant increases, so does the percentage of 4CP (4-ChloroPhenol) degradation. The half-filled La electronic structure may be acting as a trapping center for the charge carriers, which is expected to result in increased photocatalytic activity. This study creates new avenues for assessing how the development of nanomaterials will affect energy and environmental applications.</p>