Metal-Organic Framework (UiO-66-NH2) as a Dual-Functional Material for Photo-Assisted Nitroarene Reduction and Supercapacitor Applications

This study investigates the synthesis, dual functional applications, and electrochemical performance of the amine-functionalized metal-organic framework (MOF), namely UiO-66-NH2. The material was synthesized via the solvothermal method and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning and transmission electron microscopy (SEM/TEM). UiO-66-NH2 was assessed as a catalyst for the reduction of nitroarenes, specifically 2-nitrophenol (2-NP) and 4-nitrophenol (4-NP), under both dark and photo-assisted (i.e., photocatalysis) conditions. Complete photoreduction of nitroarenes was achieved under photocatalysis, highlighting its photo-assisted catalytic efficacy. UiO-66-NH2 before and after nitroarenes adsorption capacities were investigated, and subsequent electrochemical assessments confirmed its suitability as a supercapacitor electrode. Cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) analyses demonstrated that nitroarene adsorption and light irradiation markedly improved specific capacitance. 2-NP@UiO-66-NH2 showed specific capacitance of 221 F/g at 1 A/g under UV radiation. UiO-66-NH2 demonstrated remarkable cycling stability (100%) across 7000 cycles. Structural and property modifications of UiO-66-NH2, adsorption of redox-active species, and photo-assisted mechanisms can significantly enhance the energy storage efficacy. The results illustrate the dual role of UiO-66-NH2 as an effective photo-assisted catalyst and electroactive supercapacitor material, facilitating integrated environmental remediation and energy storage applications.