First principles study on high-efficient overall water splitting by anchoring cobalt boride with transition metal atoms

Developing efficient, low-cost electrocatalysts is of great significance for improving the efficiency of water electrolysis. In this work, the structure, electronic properties, hydrogen evolution reaction (HER), and oxygen evolution reaction (OER) activity of transition metal-doped cobalt boride (TM@CoB) were thoroughly investigated using density functional theory. Ni@CoB and Cu@CoB exhibited excellent catalytic activity for HER. Specifically, Ni@CoB demonstrated a ΔGH* value of 0.0537 eV, surpassing the most commonly used Pt catalyst. The reaction mechanism followed the Heyrovsky mechanism, and it also showed good OER activity, making it a potential candidate for OER electrocatalysts. Compared to the original CoB, Ni@CoB showed a 70 % improvement in HER activity and a 65 % improvement in OER activity. The Ni@CoB catalyst was synthesized, and its catalytic performance was experimentally validated. This work offers a new perspective and guidance for the development of bifunctional electrocatalysts.