Ce-doped CuO/Mg(OH) 2 nanocomposites: Structural, optical, thermal and multifunctional properties

Multifunctional nanocomposites with tuneable properties have attracted attention for environmental and biomedical applications. Ce incorporation can modify their structural, optical, thermal and functional properties. In this work, PVP (polyvinylpyrrolidone) capped Ce-doped CuO/Mg(OH) 2 nanocomposites were successfully synthesised using co-precipitation method. Three synthesised samples are identified in manuscript by the sample codes NC1, NC2, and NC3: undoped CuO/Mg(OH) 2 , 2 mol% Ce-doped CuO/Mg(OH) 2 , and 4 mol% Ce-doped CuO/Mg(OH) 2 , respectively. All samples were explored with various analytical characterisation techniques to study the influence of Ce incorporation on multifunctional properties of the nanocomposites. XRD confirmed the polycrystalline nature of nanocomposites, consisting monoclinic CuO and hexagonal Mg(OH) 2 phases, with a slight decrease in crystallite size upon Ce incorporation. HRTEM and FESEM analyses revealed the nearly spherical and sheets like morphologies, while EDS spectra and elemental mapping confirmed the presence and distribution of Cu, Mg, O and Ce. FT-IR analysis identified various functional groups present in nanocomposites, whereas XPS confirmed the oxidation states of Cu 2+ , Mg 2+ , and Ce 3+ /Ce 4+ . TGA-DSC analysis revealed weight loss and thermal decomposition behaviour of the nanocomposites. UV-visible DRS analysis exhibited low reflectance below 700 nm and a reduction in optical bandgap energy with increasing Ce concentration. The 4 mol% Ce-doped CuO/Mg(OH) 2 nanocomposite exhibited 95.67% degradation of methyl orange and 98.11% of methylene blue within 120 and 60 min, respectively, under UV-visible irradiation. The same sample achieved 90.43% DPPH free radical scavenging activity. The antibacterial assays of 4 mol% Ce-doped CuO/Mg(OH) 2 nanocomposites exhibited zone of inhibition (ZOI) of 29.33 ± 0.57 mm, and 32.66 ± 0.47 mm, against bacteria strain Escherichia coli (E. coli), and Bacillus subtilis (B. subtilis), respectively. Thus, the synthesised Ce-doped CuO/Mg(OH) 2 nanocomposites represent a new class of multifunctional materials with potential applications in photocatalysis, antioxidant and antibacterial activity.