Selective adsorption and separation of dyes from aqueous solution by core-shell structured NH2-functionalized UiO-66 magnetic composites

Core-shell structured NH 2 -functionalized UiO-66 magnetic composites (γ-Fe 2 O 3 @C@UiO-66-NH 2 ) were fabricated via a simple, facile and green approach to investigate their adsorption behaviors towards different organic dyes (methylene blue, malachite green , acid fuchsin and acid orange II). Different characterization methods containing XRD , TEM , EDXA , FTIR, BET and XPS were used to indicate that the as-prepared γ-Fe 2 O 3 @C@UiO-66-NH 2 material exhibited core-shell structure and excellent surface performance. Adsorption experiments showed that γ-Fe 2 O 3 @C@UiO-66-NH 2 could selectively adsorb anionic dyes and effectively separate the mixture, which might be mainly ascribed to the negatively-charged anionic dyes as opposite to the positively-charged Zr metal sites in γ-Fe 2 O 3 @C@UiO-66-NH 2 . The kinetics and adsorption isotherm of acid orange II and acid fuchsin adsorption in γ-Fe 2 O 3 @C@UiO-66-NH 2 were also investigated. For acid orange II and acid fuchsin, the maximum adsorption capacity obtained from the Langmuir isotherm model was 48.12 mg/g and 31.54 mg/g, respectively. Moreover, γ-Fe 2 O 3 @C@UiO-66-NH 2 exhibited good structural stability and reusability, which suggesting that γ-Fe 2 O 3 @C@ UiO-66-NH 2 as an easy-prepared adsorbent material exhibited great application potential in the selective removal of dyes from water systems.