Monolayer Mo2B: A non-magnetic metal and potential application as anode material for ion batteries and catalyst for hydrogen evolution

Abstract

Using the first principle method, the properties and electronic structures for two dimensional (2D) Mo2B are studied. Our investigations show 2D Mo2B with the hexagonal structure is a stable phase. Electronic structure show that 2D Mo2B is a typical metal and non-magnetic. The native defects, as well as a few percent of biaxial tensions and compressions cannot destroy its metallic behaviors. Stable metallic properties suggest 2D Mo2B is a promising electrode material in ion batteries. For Li and Na adsorbed cases, negative adsorption energies suggest strong interactions between Li (Na) and 2D Mo2B, which could prevent the formation of metallic Li and Na, and improve ions batteries’ safety and reversibility when utilized as anodes in ion batteries. The diffusion barriers for Li (Na) ions on 2D Mo2B are 0.073 (0.069) eV, and the open circuit voltage for Li (Na) adsorbed are 0.62–1.15 (0.42–1.41) V. Such diffusion barriers and open circuit voltage indicate 2D Mo2B is a promising anode material for Li or Na ion batteries. Smaller Gibbs free energy implies 2D Mo2B have a good prospect as a catalyst for hydrogen evolution.