A Newly Predicted Magnetic TMB6 Monolayer for Efficient Nitrogen Fixation.

Developing electrocatalysts for the N reduction reaction (NRR) with high activity, high selectivity, and low cost is urgently required to enhance the NH yield rate. Based on first-principles calculations, we predict a series of new transition metal boride TMB (TM = Ti, V, Cr, Mn, Fe, and Co) monolayers and investigate their magnetoelectronic and electrocatalytic properties. The results reveal that VB and CoB favor ferromagnetic coupling, while TiB, CrB, MnB, and FeB display antiferromagnetic ordering. Furthermore, TiB exhibits a high Néel temperature of 344 K and a large magnetic anisotropy energy of 614 μeV per Ti atom. Most interestingly, TiB and VB exhibit superior NRR catalytic activity with a limiting potential of -0.50 and -0.19 V, respectively, and favorable NRR selectivity over the HER. Finally, the structural stability of TMB monolayers has been confirmed by a set of phonon dispersion, molecular dynamics, and elastic constant calculations. Our results highlight the use of the newly designed two-dimensional (2D) TM borides as promising candidates for spintronic devices and nitrogen fixation applications.