One-step solvothermal construction of 2D CoFe dual-MOF nanosheets for synergistically enhanced oxygen evolution reaction

Developing highly efficient electrocatalysts for oxygen evolution reaction is critical for sustainable energy technologies. Herein, a two-dimensional (2D) dual-metal-organic framework (dual-MOF) nanosheet electrocatalyst, denoted as CoFe-(74+88), is constructed via a facile one-pot synthesis method by integrating CoFe-MOF-74 and CoFe-MIL-88. Remarkably, the obtained CoFe-(74+88) exhibits superb electrocatalytic OER activity in 1.0 M KOH electrolyte, achieving an overpotential of 186 mV at 10 mA cm −2 , a Tafel slope of 38.7 mV dec −1 , and excellent long-term stability. The enhanced OER performance of CoFe-(74+88) can be attributed to the electronic reconfiguration and electronic interaction through the proper combination of two different MOFs and its unique 2D nanosheet structure with uniformly distributed nanoparticles, resulting in multiple positive synergistic effects to boost the electrocatalytic activity. This study provides a promising way for designing and synthesizing 2D MOF nanosheet electrocatalysts for energy-related applications. Through a one-step solvothermal method, we successfully constructed ultrathin CoFe-(74+88) dual-MOF nanosheets (∼ 1.5 nm) on NF by integrating CoFe-MOF-74 and CoFe-MIL-88. This unique structure, combined with synergistic effects between the two MOFs and electronic reconfiguration of Co 2+ /Fe 2+ /Fe 3+ species, enables exceptional OER performance in alkaline media. • A dual-MOF CoFe-(74+88) was constructed by a one-step integration of CoFe-MOF-74 and CoFe-MIL-88. • CoFe-(74+88) exhibits a unique 2D ultrathin nanosheet structure with uniformly distributed nanoparticles, enhancing active site exposure. • Electron transfers from Fe to Co in CoFe-(74+88), leading to optimized electronic structure. • CoFe-(74+88) exhibits outstanding OER performance with low overpotential (186 mV @ 10 mA cm −2 ) and high stability.