Regulating the electronic structure of Fe-based metal organic frameworks by electrodeposition of Au nanoparticles for electrochemical overall water splitting.

Reasonable regulating the electronic structure is one of the effective strategies for improving the conductivity of metal-organic frameworks (MOFs) based electrocatalysts. Herein, a series of Fe-MOF/Au composites grown in situ on Fe Foam (FF) were prepared through a hydrothermal and the controlled electrodeposition time strategy, in which the Fe Foam acts both as the conductive substrate and a self-sacrificing template. The electronic structure of the Fe-MOF/Au/FF composites can be finely adjusted by tailoring the electrodeposition time. Therefore, the Fe-MOF/Au/FF composites possess enhanced conductivity, accompanied by increased electrochemical activity of specific areas and oxygen evolution (OER), hydrogen evolution (HER) and overall water splitting properties. In particular, the optimized Fe-MOF/Au-8/FF composites used as bifunctional electrocatalysts for overall water splitting require only small voltage of 1.61 V to achieve a current density of 10 mA cm. This strategy will provide new inspiration and creativity to enhance the electrocatalytic performance of MOF-based electrocatalysts for hydrogen conversion and application.