Synthesis of Rare Earth (Dy and Pr) Metal Impregnated Asparagine Functionalized CoFe2O4 Nanocomposite: Two Novel, Efficient and Magnetically-Recoverable Catalysts for the Reduction of 4-nitrophenol

In recent times biomolecules engineered magnetically isolable nanoparticles have garnered significant attention in the nanocatalysis arena due to their outstanding features. Doping of rare earth metals over them brings further novelty to their properties. In this current work, we describe the successful synthesis of rare earth lanthanide (M = Pr, Dy) impregnated asparagine-adorned CoFe2O4 as two novel magnetically isolable nanocomposite catalysts following a post-functionalization approach. The synthesized materials were characterized using physicochemical techniques like FT-IR, SEM, EDX, elemental mapping, and ICP-OES analyses. Subsequently, the catalytic efficiency of the materials was investigated in the reduction of 4-Nitrophenol (4-NP), a well-known carcinogenic contaminant of water. The progress of the reaction and its kinetics were monitored over UV-Vis spectroscopy. Among the two variants, Dy anchored catalyst was found to be more efficient than the Pr which led the reaction to completion in just 8 min. Kinetically, also Dy catalyst exhibited higher rate constants. This is the first report of Pr and Dy-anchored heterogeneous catalysts in the reduction of 4-NP. The current methodology is advantageous in terms of cleanliness, simple procedure, excellent yields in short reaction time, easy magnetic retrieval, and reusability of catalysts following several runs without significant change in catalytic activity.