Synergetic engineering of Zeolitic Imidazolate framework for efficient oxygen evolution reaction

The current research details the engineering of a zeolitic imidazolate framework (ZIF-8) with iron (Fe) for electrocatalytic performance in energy generation using oxygen evolution reaction (OER). The prepared materials were characterized using analytical techniques such as powdered X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The findings indicate that Fe (II) can be utilized as an iron source to synthesize Fe-ZIF-8 directly. The catalytic activity of ZIF-8 for the OER appears to be lower than that of Fe-ZIF-8, which translates to reduced electrocatalytic OER overpotential. The overpotential of 10-Fe-ZIF-8 is significantly lower (i.e., 184 mV at 10 mA/cm²) than that of the benchmark IrO₂ (η10 = 270 mV) vs. reference hydrogen electrode (RHE) for the OER. Fe-ZIF-8 electrode showed advantageous electrochemically active surface area and electrochemical impedance. Potentiostatic measurements were conducted for 55 h to evaluate the electrochemical stability of the Fe-ZIF-8 electrode with continuous oxygen production with a Faradic Efficiency (FE) of 94.6%. The research findings indicate the synergetic of Fe and Zn in ZIF-8 exhibits potential for electrocatalytic water splitting.