Enhanced Electrocatalytic Capacity of Two POM@NH₂‐MIL‐101(Fe) Composites for Oxygen Evolution Reaction

Abstract The development and exploration of efficient bifunctional electrocatalysts for water splitting are in high demand and have garnered significant attention in recent years. Herein, by incorporating the advantages of catalytically active polyoxometalates (POMs) and structural stable metal–organic frameworks (MOFs), two POM@MOFs composite materials, Ni 4 Mo 12 @Fe and Co 4 Mo 12 @Fe, have been successfully prepared via the encapsulation of POMs anions, [Mo V 12 O 30 ( μ 2 ‐OH) 10 H 2 {Ni II 4 (H 2 O) 12 }]∙14H 2 O (noted as Ni 4 Mo 12 ) and [Mo V 12 O 30 ( μ 2 ‐OH) 10 H 2 {Co II (H 2 O) 3 } 4 ]∙12H 2 O (noted as Co 4 Mo 12 ), into the cavities of MOFs NH 2 ‐MIL‐101(Fe), respectively. Compared to each individual components, Ni 4 Mo 12 @Fe and Co 4 Mo 12 @Fe composites, as heterogeneous electrocatalysts, both showed enhanced electrocatalytic capacities for efficient oxygen evolution reaction (OER) under alkaline conditions with overpotentials of 332.64 mV for Ni 4 Mo 12 @Fe and 352.64 mV for Co 4 Mo 12 @Fe at 10 mA cm −2 . Additionally, the enhanced electrocatalytic capacities of these two composites could also achieve towards hydrogen evolution reaction (HER). Such a POMs‐assisted strategy for the formation of POM@MOFs composites, described here, paves a new avenue for the development of highly economical, active nonnoble metal bifunctional electrocatalysts for OER and HER.