FeNi-based bimetallic MIL-101 directly applicable as an efficient electrocatalyst for oxygen evolution reaction

Abstract Metal–organic frameworks (MOFs) have been widely used in the field of electrocatalysis in recent years. In most reports, an MOF is used as a sacrificial template to prepare a highly efficient electrocatalyst by calcination. Here, a series of FeNi bimetallic MIL-101 materials has been synthesized by a solvothermal method and directly applied for the oxygen evolution reaction (OER). These MOFs contain a large number of catalytically active MO 6 octahedra and exposed hydrophilic carboxyl groups, which are believed to enhance OER activity. In addition, after the introduction of Ni, the catalytic activity is significantly improved by synergy between the metals. Among the studied compositions, Fe 2 Ni-MIL-101 showed the best OER performance, requiring a low overpotential of just 237 mV to drive a current density of 20 mA cm −2 in 1  m KOH solution, corresponding to a low Tafel slope of 44.2 mV dec −1 . Moreover, the electrochemical properties remained virtually unchanged during a 40-h long-term stability test. These findings enrich the application of MOFs materials in the field of electrocatalysis.