Bio-engineered Ce/Ba doped and Ce–Ba Co-doped CuO and Co3O4 nanoparticles for improved photocatalytic and biological assessments

CuO and Co₃O₄ NPs are renowned nanomaterials due to their exceptional features that contribute to the antibacterial and photocatalysis domains. In this study, Ce/Ba doped and Ce–Ba co-doped CuO and Co₃O₄ nanoparticles (NPs) were engineered via a green method to enhance antibacterial, antioxidant efficiency and degrade congo red and rhodamine B by photocatalysis under UV radiations. The physicochemical properties of the NPs were identified by using several analytical techniques. The crystallite sizes of monoclinic Ce/Ba doped and Ce–Ba co-doped CuO were 12.38 and 9.92 nm, respectively, as confirmed by XRD. Similarly, the cubic samples of Ce/Ba doped and Ce–Ba co-doped Co₃O₄ NPs exhibited crystallite sizes of 12.94 and 6.08 nm. The FTIR analysis recorded the possible involvement of functional groups of biomolecules in the synthesized samples. The distribution of elements and their morphology was further indicated by SEM-EDX and TEM. The band gap values viz. 1.09 and 1.15 eV were determined from the UV–vis absorption analysis for Ce–Ba co-doped CuO and Co₃O₄ NPs, respectively. In particular, the Ce–Ba co-doped CuO degraded 93.20 and 91.56 % of congo red and rhodamine B within 50 and 60 min, respectively as compared to Ba-doped CuO showing 80–86 % degradation for both dyes. The scavenging activity shown by the same sample was also 88.67 %. The Ce–Ba co-doped CuO NPs exhibited the highest bacterial killing efficacy against gram- (+) and (−) bacteria. The exceptional performance of the samples was ascribed to the coupling of single-doped CuO and Co₃O₄ NPs with the Ce ions for upgrading the properties of the material for a sustainable ecosystem.