Cl modulation on boron-rich carbon embedded with NiFe alloys for efficient oxygen evolution reaction

The rational design of cost-effective oxygen evolution reaction (OER) electrocatalysts is important for the future global energy supply but remains a formidable challenge. Herein, Cl-doped boron-rich carbon nanocomposites embedded with NiFe alloys (FexNiy@ClBC) were constructed via a facile mechanochemical-assisted strategy for use as an OER electrocatalyst. Combination of the unique Cl-doped boron-rich carbon species with the NiFe alloy optimized the electronic structure and surface properties. Meanwhile, Density flooding theory (DFT) calculations confirmed that the Fe1Ni2@ClBC catalyst weakened the strong adsorption of *O and *OOH intermediates due to the introduction of Cl, which reduced the Delta Gmax of the OER process and led to a more favorable reaction kinetics. As a result, this catalyst exhibited a remarkable OER performance with a low overpotential (259 mV at 10 mA cm- 2, 296 mV at 50 mA cm- 2) and a small Tafel slope (49 mV dec-1). The Fe1Ni2@ClBC catalyst exhibited a considerable stability under harsh alkaline conditions for over 40 h because of its external highly robust porous carbon shell. This work contributes to the understanding of nonmetallic heteroatom-doped carbon materials and should inspire the design of low-cost alloy electrocatalysts.