TMB2C (TM = Ti, V): 2D transition metal borocarbide monolayer with intriguing electronic, magnetic and electrochemical properties

Designing two-dimensional materials with intriguing electronic and magnetic properties holds great potential for electronic and spintronic device application. By means of density functional theory calculations, we predicted a class of 2D MXene-like transition metal (TM) borides, TMB2C (TM = Ti, V, Cr, Mn, Fe) monolayer and their TMB2CX analogues by terminating various functional groups (X = H, O, F, S). The results show that two TMB2C monolayers at TM = V and Cr are thermodynamically stable with lager cohesive energies and positive frequencies in the phonon dispersion bands. TiB2C is antiferromagnetic (AFM) semiconductor and VB2C is ferromagnetic (FM) half metal with a high Curie temperature (Tc) of similar to 580 K. Moreover, TiB(2)CXs and VB(2)CXs (X = H, O, F, S) show better mechanical stability and distinct electronic and magnetic properties with semiconductor-(half) metal and FM-AFM transform. Interestingly, VB2CF is revealed to exhibit excellent hydrogen evolution reaction (HER) performance with an adsorption Gibbs free energy for H atom close to zero (delta G(H*) = 0.03 eV). The high stability and excellent properties make TMB2C(X) monolayer a promising candidate for potential spintronic and electrocatalytic application.

Automated summary

By utilizing density functional theory calculations, a class of two-dimensional MXene-like transition metal borides with intriguing electronic and magnetic properties were predicted. The results showed that two of these materials are thermodynamically stable with large cohesive energies and positive frequencies in the phonon dispersion bands.