Layered double hydroxide derived bimetallic nickel–iron selenide as an active electrocatalyst for nitrogen fixation under ambient conditions

Abstract

During the last few years, the electrocatalytic nitrogen reduction reaction (NRR) has provided an environmentally friendly and promising alternative to the Haber–Bosch process. However, due to the competing hydrogen evolution reaction and the hard-to-break strong NN bond with high bond energy (941 kJ mol⁻¹), the synthesis of efficient NRR catalysts is still a challenge. Herein, we report a cost-effective layered double hydroxide (LDH) derived bimetallic NiFe selenide (Ni_0.75Fe_0.25Se₂) in Li₂SO₄ solution for NRR under ambient conditions, which exhibits an NH₃ yield rate of 5.64 μg h⁻¹ cm⁻²_cat and faradaic efficiency of 12.3% at −0.1 V vs. RHE, being superior to those of pristine NiFe–LDH, NiSe₂, and FeSe₂ as well as several state-of-the-art noble metal catalysts. The high electrocatalytic NRR activity and selectivity of Ni_0.75Fe_0.25Se₂ demonstrate the first example of NiFe selenide catalyst with a facile synthesis strategy towards efficient nitrogen fixation.