Engineering Electronic and Morphological Structure of Metal-Organic-Framework-Derived Iron-Doped Ni2P/NC Hollow Polyhedrons for Enhanced Oxygen Evolution

Therational design of an oxygen electrocatalyst with low costand high activity is greatly desired for realization of the practicalwater-splitting industry. Herein, we put forward a rational methodto construct nonprecious-metal catalysts with high activity by designingthe microstructure and modulating the electronic state. Iron (Fe)-dopedNi(2)P hollow polyhedrons decorated with nitrogen-doped carbon(Fe-Ni2P/NC HPs) are prepared by a sequential metal-organic-framework-templatedstrategy. Benefiting from the strong electronic coupling, rapid charge-transfercapability, and abundant catalytic active sites, the obtained Fe-Ni2P/NC HPs exhibit an impressive electrocatalytic performancetoward the oxygen evolution reaction (OER) with an ultralow overpotentialof 228 mV at a current density of 10 mA cm(-2) anda small Tafel slope of 33.4 mV dec(-1), superior tothe commercial RuO2 and most reported electrocatalysts.Notably, this catalyst also shows long durability with an almost negligibleactivity decay over 210 h for the OER. Combining density functionaltheory calculations with experiments demonstrates that the doped Feand the incorporated carbon effectively modulate the electronic structure,enhance the conductivity, and greatly reduce the energy barrier ofthe rate-determining step in the process of OER. Thus, fast OER kineticsis realized. Moreover, this synthetic strategy can be extended tothe synthesis of Fe-NiS2/NC HPs and Fe-NiSe2/NC HPs with excellent OER performance and long-term durability.This work furnishes an instructive idea in pursuit of nonprecious-metalmaterials with robust electrocatalytic activity and long durability. A sequential metal-organic-framework-templatedstrategyis developed to prepare iron-doped Ni2P hollow polyhedronsdecorated with nitrogen-doped carbon (Fe-Ni2P/NC HPs),which require an ultralow overpotential of 228 mV to achieve a currentdensity of 10 mA cm(-2), superior to commercial RuO2 and other comparative electrocatalysts.

Automated summary

In this study, a rational method was proposed to design nonprecious-metal catalysts with high activity for the oxygen evolution reaction (OER). Fe-doped Ni2P hollow polyhedrons decorated with nitrogen-doped carbon showed impressive electrocatalytic performance, surpassing commercial RuO2 and other comparative electrocatalysts. The synthetic strategy used in this work can also be extended to other materials, demonstrating the potential for developing robust electrocatalysts with long-term durability.