Facile synthesis of green and efficient magnetic nanocomposites of carrageenan/copper for the reduction of nitrophenol derivatives.

A green and facile method for preparation of Kappa-Carrageenan or Iota-Carrageenan grafted N,N'-methylenebisacrylamide/Fe3O4/Cu nanoparticles (κC-g-MBA/MNPs/Cu and ιC-g-MBA/MNPs/Cu) catalysts was developed to place copper on a magnetic carrageenan surface. The structure and morphology of the prepared catalysts were identified using FT-IR, XRD, BET, VSM, TGA, EDX, mapping, FE-SEM, TEM, and ICP-OES analyses. The catalytic activity of the catalysts was investigated to reduce 4-nitrophenol, 2-nitrophenol, 3-nitroaniline, and 4-nitroaniline compounds using the UV-Vis spectrum. To reduce 4-nitrophenol using κC-g-MBA/MNPs/Cu and ιC-g-MBA/MNPs/Cu, the rate constants (Kapp) obtained were 0.37 and 0.25 min-1, and the activity factors (k') were 134 and 193 s-1 g-1, respectively. The catalysts had a good performance in reducing the nitrophenol compounds and due to the magnetic properties of the catalysts, they could easily be separated and used multiple times.