Amino-functionalized iron-based MOFs modified with 2D FeCo(OH)x hybrids for boosting oxygen evolution.

• Defect-rich hierarchical hybrid was fabricated by simultaneous etching and coprecipitation. • Hybrid was constructed by amino-functionalized iron-based MOFs and FeCo(OH) x nanosheets. • Hybrid have larger specific surface area and high hydrophilicity. • Hybrid have faster access of electrolytes and release of gas bubbles due to abundant defect and high hydrophilicity. • The hybrids exhibited the superior activity and stability for OER, which exceeds commercial RuO 2 electrocatalyst. MOFs modified FeCo(OH) x hierarchical architecture with larger specific surface area and high hydrophilicity is fabricated through the simultaneous etching and coprecipitation operation, which exhibits a superior electrocatalytic OER activity and excellent electrochemical stability. [Display omitted] The multiple nanoarchitecture of hybrids integrated hydroxides with metal organic framework (MOF) is a new type of promising electrocatalysts for oxygen evolution reaction (OER). However, most of these catalysts have the poor electrical conductivity and superhydrophobicity which seriously restrict their practical applications. In this paper, an amino-functionalized iron-based MOF modified FeCo(OH) x (denoted as Am-FeCo(OH) x) hybrid is fabricated via the simultaneous operation of the etching for iron-based MOF octahedron and the coprecipitation for the metal cation in the etchants. Compared to iron-based MOF and hydroxide, Am-FeCo(OH) x hierarchical architecture manifested the enhanced catalytic activity and hydrophilicity, which can be attributed to the more exposed active sites, the accelerating access of electrolytes, the promoted proton-coupled electron transfer capability and the efficient release of gas bubbles. The optimized Am-FeCo(OH) x exhibited an excellent OER activity with a low overpotential of 257 mV at 10 mA cm−2, and robust electrochemical stability with no obvious degradation over 16 h. This work provides an effective methodology for rational design of other hydrophilic hydroxide composites targeting the electrocatalysts with high performance for water splitting. [ABSTRACT FROM AUTHOR]