Synthesis, magnetic and adsorption of dye onto the surface of NiO nanoparticles.

NiO was synthesized simply via thermal decomposition of nickel ascorbate, which resulted from semi-solid reaction of nickel acetate and ascorbic acid. The prepared precursor was characterized by elemental, thermal and spectral analyses. The precursor was decomposed at 700 °C producing cubic NiO with average size 50 nm as indicated from XRD and TEM. FESEM indicated the formation of macroporous NiO. Magnetic parameters (saturation magnetization (M_s), remanence (M_r) and coercivity (H_c)) of NiO nanoparticles and its precursor were determined and compared with the bulk nickel. Zeta potential measurements at different pH values indicated that NiO is negatively charged. Adsorption of ponceau xylidine dye onto NiO nanoparticles at different parameters as pH, amount of adsorbent and time of adsorption was studied. It was found that the adsorption behavior obeys Langmuir isotherm and intra-particle diffusion model. NiO can remove 97.2% of ponceau xylidine from aqueous media. NiO showed higher adsorption than some other reported adsorbents. In additional to that, the antimicrobial effect of NiO-NPs on Staphylococcus aureus, Candida albicans and Escherichia coli was investigated. NiO nanoparticles exhibited good effects against the tested species. [ABSTRACT FROM AUTHOR]