Rapid and Facile Electrochemical Synthesis of MIL-101(Fe)-NH2 and Its Curcumin Loading and Release Studies

Metal-organic frameworks (MOFs) receive great attention for their wide spectrum of applications ranging from catalysis to biomedical applications. Despite the progressively growing scope of their functionalization and application, the synthesis method to achieve the material in such a short time and high yield is still a challenge. In this study, we performed the electrochemical preparation of MIL-101(Fe)-NH2 for the first time. The obtained material exhibited similar physico-chemical properties compared to those prepared with a solvothermal method. Analysis using X-ray diffraction (XRD) showed that the electrochemically-synthesized MIL-101(Fe)-NH2 demonstrates high suitability with the standard pattern at 2 theta 9.28, 10.3, and 16.72 degrees. Further analysis using Fourier Transform Infrared Spectroscopy (FTIR) confirmed that the proposed method had successfully produced the desired materials, as observed from the shift of C = O bond absorption band from 1688 cm(- 1) to lower wavenumber and the presence of C-N bond at 1336 cm(- 1) as well as the asymmetrical and symmetrical stretching vibration of N-H at 3470 and 3368 cm(- 1). Nitrogen sorption isotherm confirmed the material occupies micro-porosity with an average pore size of 2.6 nm. The Field Emission Scanning Electron Microscopy-Energy Dispersive Spectroscopy (FESEM-EDS) and Transmission electron Microscopy (TEM) analysis revealed that the material occupies a micro-spindle shape. Moreover, Thermogravimetric analysis (TGA) showed that the material is thermally stable up to 250 degree celsius. Loading of curcumin into MIL-101(Fe)-NH2 via a post-synthesis strategy showed that solvothermal-synthesized MIL-101(Fe)-NH2 (MIL-101(Fe)-NH2-S) exhibited the highest loading efficiency up to 91.7% in 48 h. The release study revealed that the slowest release of the drug was observed in MIL-101(Fe)-NH2-S in an acidic medium (pH 4.8) and the release kinetic followed the non-Fickian diffusion.