Metal-organic frameworks (MOFs) based oxygen-evolution reaction (OER) catalyst is an emerging class of highly porous materials that have become increasingly attractive to develop a highly active and stable OER catalyst for overall water splitting. However, it suffers from poor conductivity and inadequate active sites. Herein, we have developed a series of hierarchical Fe-mediated Ni-based metal-organic frameworks (FexNi1-x-MOF) by an adjustable hydrolysis strategy, where the Ni-MOF is used as a template that is decorated with NiOOH active sites. Although Ni-MOF is dissociated during the ion exchange process, the structural integrity is kept for FexNi1-x-MOF as confirmed by the electron micrographs. Moreover, the optimized Fe0.38Ni0.62-MOF catalyst not only exhibits a remarkable OER catalytic performance with a low overpotential of 190 mV at 10 mA cm-2 but also shows a small Tafel slope of 58.3 mV dec-1 and stability. The excellent OER electrocatalytic activity can be attributed to the unique 3D flower-like structure decorated with NiOOH active sites induced by Fe3+ species. This novel methodology expands a new way for the construction of highly efficient alkaline catalytic materials.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work has been supported by the National Natural Science Foundation of China (Grant No. 21965005), the Natural Science Foundation of Guangxi Province (Grant Nos. 2018GXNSFAA294077 and 2017GXNSFGA198004), the Project of High-Level Talents of Guangxi (Grant Nos. FKA18015 and 2018ZD004), and the Innovation Project of Guangxi Graduate Education (Grant Nos. XYCSZ2019056 and YCBZ2019031).