Synthesis of Magnetically Recoverable Nickel (II) Complex-Functionalized Fe 3 O 4 @ISNA (ISNA= Isonicotinic acid) Nanomaterials: Catalytic Studies on Nitrophenol Reduction and TD- DFT Studies

Abstract

In this study, we aimed to develop a novel, environmentally sustainable, and magnetically separable heterogeneous nanocatalyst, denoted as Fe 3 O 4 @ISNA@NiL (where L represents the ligand). The synthesis involved a two-step process, first, isonicotinic acid was chemically grafted onto the surface of iron oxide nanoparticles (Fe 3 O 4 ) to introduce functional groups capable of further chemical modification. Subsequently, a nickel(II) Schiff base monomeric complex was anchored onto the modified surface, resulting in a nanocatalyst with enhanced catalytic properties and magnetic separability, facilitating its recovery and reuse in various catalytic applications.The nanocatalyst was thoroughly characterized using various physicochemical techniques, including Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Powder X-ray Diffraction (PXRD). These analyses confirmed the successful surface modification of the magnetic Fe 3 O 4 core. The DFT calculations of the spectral data of the NiL complex had also been done. We investigated the reduction capabilities of Fe 3 O 4 @ISNA@NiL using p-nitrophenol as a model substrate, optimizing the reaction conditions via UV-Vis spectroscopy. Under optimal reaction conditions, nearly complete reduction of p-nitrophenol (PNP) to the corresponding product p-aminophenol (PAP) was achieved within 10minutes, with a rate constant of 0.09min⁻¹. Moreover, the nanocomposite exhibited high stability and reusability, retaining its catalytic efficiencyforup-to5cycleswhen manipulated with an external magnetic field.