Effect of seaweed Kappaphycus alvarezii in the synthesis of Cu@Cu2O core–shell nanoparticles prepared by chemical reduction method

This study aims is to investigate the influence of different concentrations of Kappaphycus alvarezii ( K . alvarezii ) for the synthesis of Cu@Cu 2 O core–shell nanoparticles (NPs) in aqueous solution. The core–shell NPs were prepared by a chemical reduction method using K . alvarezii , CuSO 4 ·5H 2 O, NaOH, ascorbic acid, hydrazinium hydroxide, as stabilizer, copper precursor, pH moderator, antioxidant and reducing agent under 120 °C temperature, respectively. Formation of Cu@Cu 2 O-NPs was determined by UV–Vis spectroscopy where surface plasmon absorption maxima can be observed at 390-590 nm. The synthesized core–shell NPs were also characterized by X-ray diffraction. Moreover, the morphology and structure of the K . alvarezii /Cu@Cu 2 O-NPs were investigated by TEM, FESEM and EDXRF. The Fourier transform infrared spectrum suggested the complexation present between K . alvarezii and Cu@Cu 2 O-NPs. The study clearly showed that using various amounts of K . alvarezii leads to produce different ratios and sizes of Cu@Cu 2 O NPs. The size of the Cu@Cu 2 O-NPs decreased as the amount of K . alvarezii was increased. The ratio of Cu@Cu 2 O increases with the increasing concentration of K . alvarezii until 0.2 wt%.