Methyl Orange Adsorption by Fe₂O₃@Co-Al-Layered Double Hydroxide ^†

A magnetic composite consisting of iron oxide and a cobalt–aluminum-layered double hydroxide, Fe₂O₃@Co-Al-layered double hydroxide was prepared through linking of Fe₂O₃ to Co-Al layered double hydroxide (LDH) by sodium acetate. Layered double hydroxides are generally described as [M²⁺_1–xM³⁺_x(OH)₂] [A_n–x/n·mH₂O], where M²⁺ and M³⁺ are divalent and trivalent metal cations, respectively, and A is an n-valent interlayer guest anion. The composite was characterized by XRD, FTIR and UV-Vis. spectroscopy methods. Afterwards, the composite was used for methyl-orange adsorption in aqueous solution. The UV–Vis spectrum indicates that the adsorption process was satisfying. In effect, after several washings of the composite, no decrease of the adsorption capacity was observed.