Fabrication of an iron-doped Fe@Zn-MOF composite: empowering enhanced colorimetric recognition and energy storage performance

Abstract

Metal organic frameworks (MOFs) have become highly promising materials for a wide range of applications because of their distinct characteristics and structural adaptability. The utilization of MOFs in composite materials has the potential to expand their range of applications. This study focuses on the development of an iron-doped zinc metal organic framework (Fe@Zn-MOF-2) using a previously synthesized zinc-based MOF. The efficacy of Fe@Zn-MOF-2 was investigated for sensing Gd³⁺ and acetophenone, as well as its potential as an electrode material for energy storage devices. The photoluminescence sensing experiments showed a significant improvement in the efficiency of sensing Gd³⁺ and acetophenone when using the Fe@Zn-MOF-2 composite. The composite achieved sensing efficiencies of 97.73% and 98.45%, respectively, which were higher than the efficiencies of 33.25% and 35.71% observed when using only the Zn-MOF. Furthermore, both materials exhibited substantial disparities in specific capacitance when examined as energy storage electrodes through the methods of cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) analysis, and electrochemical impedance spectroscopy (EIS). Fe@Zn-MOF-2 exhibits a specific capacitance of 318.09 F g⁻¹, while the Zn-MOF has a specific capacitance of 33.00 F g⁻¹. Fe@Zn-MOF-2 exhibits a specific capacitance retention of 94.57% after undergoing 2000 cycles in cyclic voltammetry. The results emphasize the capability of Fe@Zn-MOF-2 for versatile uses in sensing and energy storage.