Multi metallic electro-catalyst design for enhanced oxygen evolution reaction: Immobilizing MnFe nanoparticles on ZIF-67-decorated graphene oxide

The advancement of large-scale hydrogen production and its application via electrocatalytic water splitting heavily relies on progress in developing highly active inexpensive, and efficient electrocatalysts for oxygen evolution reactions (OER), which continues to pose a significant challenge. Herein, we prepare GO@ZIF67@MnFe with embedded iron (Fe) and manganese (Mn) nanoparticles on graphene oxide (GO) decorated with a zeolitic imidazolate framework (ZIF-67) using a facile and cost-effective method. The as-prepared GO@ZIF-67@MnFe catalyst exhibits remarkable electrocatalytic activity with a low overpotential of only 236 mV at the current density of 10 mA cm-2, a small Tafel slope of 55.7 mV dec-1, and robust durability in 1.0 M KOH electrolyte. Additionally, we conduct a systematic study to investigate the electrocatalytic OER activity of ZIF-67, ZIF-67@Mn, ZIF-67@Fe, and ZIF-67@MnFe using density functional theory (DFT) calculations. The experimental and DFT calculation results suggest that the introduction of Fe and Mn to ZIF-67 improves OER performance by reducing the activation energy barrier and accelerating kinetics. This study presents a promising strategy and rational design methodology for the developing multi-metallic catalysts utilizing ZIF derivatives for water splitting.