High-performance zinc-cobalt metal-organic framework embedded with reduced graphene oxide (ZnCo-MOF@rGO) for advanced energy storage and efficient electrocatalysis in hydrogen evolution reaction

The use of advanced electrode materials for energy storage devices is currently a critical area of research. In this study, a mixture of zinc cobalt metal–organic framework incorporated with reduced graphene oxide (ZnCo-MOF@rGO) is synthesized and utilized for energy storage and electrocatalysis purposes. The composite material is characterized using various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR), to verify its composition, morphology, and structural properties. The produced ZnCo-MOF@rGO electrode exhibits a specific capacity of 1664 C/g at 2.0 A/g due to the presence of a large number of active sites, significantly surpassing that of single Zn-MOF (974 Cg⁻¹) and Co-MOF (1194 Cg⁻¹). ZnCo-MOF@rGO serves as the anode, while activated carbon serves as the cathode in a hybrid device developed herein. At a current density of 1.0 Ag⁻¹, the hybrid device achieves a high energy density of 70 Whkg⁻¹ and a power density of 750 Wkg⁻¹. A stability test following 12,000 charging-discharging cycles reveals an 86 % specific capacity retention. Furthermore, the composite ZnCo-MOF@rGO demonstrates superior electrocatalytic performance, exhibiting a 90 mV overpotential. In the future, a 50/50 wt ratio binary compound ZnCo-MOF@rGO could prove to be an excellent alternative for highly effective energy storage applications.