Metallurgical slag properties as a support material for bimetallic nanoparticles and their use in the removal of malachite green dye

Abstract

Fe-Cu oxides nanoparticles (Nps) were embedded in two steel slag wastes (SSB and SSW) to develop SSB/ 33 Fe-Cu and SSW/Fe-Cu nanocomposites. Nps with mean sizes between 10–20 and 6–10 nm on SSW and 34 SSB, respectively are agglomeration with a different shape. Their characteristics were investigated by 35 XRD, TEM, BET, SEM techniques. The Nps modified the morphology of both support materials. XRD 36 pointed out the presence of Cu and Fe. The proportion of Cu concentration was higher than the one of 37 Fe. Nanocomposites were tested in malachite green removal from aqueous solution. The adsorption 38 kinetic indicated physisorption and chemisorption as the main mechanisms of adsorption. The adsorp- 39 tion capacities were 88.26 and 63.55 mg/g for SSW/Fe-Cu and SSB/Fe-Cu, respectively. This novel, easy 40 to prepare and low-cost nanocomposites is an efficient adsorbent material. The presence of calcium com- 41 pounds may improve Nps deposition an MG removal. Materials with ferric phases are not as efficient as 42 the first one; Fe is not well supported on the material. The removal of MG took place by dye structure 43 modification and by interactions with Cu nanoparticles improving the oxidation-reduction process, 44 through synergic effects.