Theoretically evaluating transition metal activated two-dimensional bilayer tetragonal AlN nanosheet for high-performance HER/OER/ ORR electrocatalysts

The search for catalysts with high activity in hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) processes has been an eminent avenue for mankind to acquire clean and renewable energy. To this end, more than a dozen transition metal (TM)-doped AlN systems have been investigated based on first-principles calculations in this study. Our calculation results show that Co@AlN-VAl can be operated as OER/ORR bifunctional catalysts with eta OER/eta ORR of 0.5/0.33 V. Meanwhile, Pd@AlN-VAl exhibits the most excellent catalytic activity due to the very low HER overpotential (eta HER = 0.009V). Furthermore, the origin of the high activity for Co@AlN-VAl in the OER/ORR process is illustrated by stating the d-band center and descriptor (phi). The Bader charge, the crystal orbital Hamiltonian population (COHP), spin density, and density of states (DOS) are analyzed to further recognize the intrinsic characteristics of this system. The study provides theoretical guidance for the application of AlN system in electrocatalysis and a window for new SACs.