Origin of pure and C doped borophene stability and its activity for OER

• We give a deeper reasoning relating vacancy, electronic structure and stability. • Vacancy increases σ and decreases π occupancies of the neighbouring boron atoms contributing to stability. • Carbon doping reduces the σ electrons of the adjacent boron atoms making them less reactive towards O* intermediate. • Dual carbon doping makes β12 borophene more efficient towards oxygen evolution reaction. In borophene, vacancy is a major reason for stability. However, a detailed understanding relating to vacancy and electronic property remains unexplored. Using Density Functional Theory (DFT) the effect of vacancy and doping on stability, electronic and catalytic properties of borophene is addressed in this work. It is shown how vacancy increases σ-electrons and decreases π-electrons of the neighboring boron atoms with the magnitude decreasing from 4 to 6-coordinated atoms, thereby contributing to their stability. The role of single and dual carbon doping on σ- and π-occupancy is explored. In addition, we have shown that dual carbon doping on β 12 -borophene analogue reduces the overpotential for oxygen evolution reaction (OER). We observed that the charge deficient boron atom helps in the reduction of oxygen binding and can decrease the overpotential towards OER. Overall, this work would help in fundamental understanding towards borophene stability and aid in choosing the suitable dopant for catalytic applications considering the stability.