Fe-Al based nanocomposite reinforced hydrothermal carbon: Efficient and robust absorbent for anionic dyes

Nanocomposites with ultrahigh adsorption capabilities are highly desired for efficient wastewater remediation. Unfortunately, most of the nanomaterial based adsorbents showing inevitable limitation such as leaching and agglomeration led to the emerging field of carbonaceous hybrid materials with nanocomposites. Herein, we demonstrated a simple and low-temperature hydrothermal assisted preparation of Fe-Al based nanocomposites immobilized using carbon spheres. Towards this, we have approached two different routes one is hybridizing with nanocomposite and another is doping on the surface of the carbon spheres. Iron doping played a dual-faceted role of active site for robust adsorption as well as induce magnetic property to the composites. The micro-cleaners have been extensively characterized for their physicochemical properties and adsorption capacities using FTIR, Raman, XRD, BET isotherms and XPS techniques. Remarkably, microcleaners shows robust adsorption where >99% removal was obtained within 10 min for 50 mg L^-1 concentrated Eriochrome Black T (EBT) dye using 0.01 g of materials. Further, adsorption data followed the pseudo second order kinetics while the equilibrium data fitted perfectly into the Langmuir adsorption equation. As synthesized user friendly microcleaner (HTC-2) exhibits maximum adsorption capacity (q_max) of 564.97 mg g^-1 for EBT dye at pH 4. Hence, the preliminary results highlight the potential of the composites to be used in pretreatment steps of industry effluents.