Theoretical and experimental exploration of tri-metallic organic frameworks (t-MOFs) for efficient electrocatalytic oxygen evolution reaction

High performance and cost-effective electrocatalysts are crucial to the oxygen evolution reaction (OER) in water splitting. Herein, we use density functional theory (DFT) calculation to systematically explore the catalytic activities of single-metallic organic frameworks (s-MOFs, such as Fe36C108O156), dual-metallic organic frameworks (d-MOFs, such as Fe26Co10C108O156, Fe30Ni6C108O156), and tri-metallic organic frameworks (t-MOFs, such as Fe26Ni2Co8C108O156) for electrocatalytic OER. The DFT calculation and experimental results suggest that the OER performance could be promoted with reduced activation energy barrier and accelerated kinetics by introducing Co and Ni into the unit cell of Material of Institute Lavioisier (MIL). The optimized t-MOFs exhibited an ultra-low overpotential of only 200 mV at the current density of 10 mA cm−2 and a small Tafel slope of 34 mV dec−1. This work proposes that the t-MOFs induced multi-metallic active sites and synergetic effect are promising strategies in designing highly efficient and robust OER electrocatalysts.