Structural functionalization of TEMPO modified Ni-MOF for electrocatalytic applications

Despite their promise, the low conductivity of Metal-Organic Frameworks (MOFs) impedes their effectiveness as electrocatalysts. To address this limitation and boost electron transport and structural stability, functionalization techniques can be applied. This work specifically details the enhancement of Ni-MOF's electronic structure and activity via TEMPO modification, evaluating its efficacy for alcohol oxidation reactions. The findings are intended to advance the prospects for utilizing MOFs in electrocatalytic applications. The study synthesized TEMPO-modified Ni-MOF (Ni-TEMPO-MOF) via a hydrothermal method and characterized its structure and composition using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and Fourier Transform Infrared Spectroscopy (FTIR). The redox behavior, electrocatalytic activity, and stability were evaluated using Cyclic Voltammetry (CV), Linear Sweep Voltammetry (LSV), Electrochemical Impedance Spectroscopy (EIS), and Chronoamperometry (CA) tests, with a comparative analysis to unmodified Ni-MOF. Experimental results indicate that TEMPO modification optimized the electronic structure of Ni-MOF, enhancing charge transfer efficiency and catalytic performance. The investigation demonstrated that TEMPO functionalization significantly improved the electronic configuration of Ni-MOF, boosting both charge transportation capability and catalytic effectiveness. Electrochemical analysis revealed a 47.0% enhancement in oxidation peak current density for Ni-TEMPO-MOF versus pristine Ni-MOF, along with a 0.04 V reduction in onset potential and improved Tafel slope (86.6 mV/dec), suggesting superior catalytic kinetics. EIS measurements indicated approximately 60% lower charge transfer resistance, while chronoamperometry tests showed enhanced durability with merely 50% current loss after 3600 s, outperforming unmodified Ni-MOF (68% decay). This work establishes that TEMPO incorporation successfully augments the electrical conduction properties and electrocatalytic performance of Ni-MOF, presenting novel approaches for MOF utilization in electrocatalytic oxidation processes and valuable insights for developing efficient electrocatalytic materials.