Theoretical study on the superconductivity of graphene-like TMB6 (TM = Cr, Fe and Co) monolayer and its potential anchoring and catalytic properties for lithium–sulfur batteries†

In recent years, two-dimensional materials have aroused enormous interest owing to their superior electrochemical performance, abundant exposed active sites, high specific surfaces and so on. Unlike many stable allotropes, honeycomb hexagonal borophene is kinetically unstable. In this study, we introduce transition metal atoms (Cr, Fe and Co) to stabilize honeycomb hexagonal borophene, forming stable graphene-like TMB₆ (TM = Cr, Fe and Co) monolayers. Moreover, we explored the possibility of superconductivity and the anchoring materials of lithium–sulfur batteries using the first-principles density functional theory (DFT) calculation. Our results show that CoB₆ exhibited the best superconductivity with a superconducting transition temperature of 33.3 K. Furthermore, CoB₆ and FeB₆ are promising anchoring materials because of the suppression of lithium polysulfides shuttling in lithium–sulfur batteries because they can accelerate sulfur reduction reaction kinetics.