Synergic Effect in a New Electrocatalyst Ni2SbTe2 for Oxygen Reduction Reaction

Pt and Pt-based materials are still the most common catalysts for oxygen reduction reaction (ORR), but it is highly desirable to develop efficient ORR electrocatalysts based on inexpensive metals. This paper presents a novel two-dimensional transition metallic chalcogenide material Ni2SbTe2 for ORR, which has a stable 3D counterpart and can be obtained through exfoliation. First-principles calculations show that the edge sites of few-layer Ni2SbTe2 possess better ORR performances than the basal plane. The (014) and (2-10) surfaces are not only energetically favorable, but also demonstrate high ORR onset potentials of 0.82 V and 0.63 V, respectively. An interesting triple-element synergic effect has been revealed in the Ni-Sb-Te system, where Te helps to reduce the bonding strength between surface Ni and adsorbed O. Meanwhile, the capability of Sb to donate different numbers of electrons, and the relatively stable 3d10 shell of Ni are shown to be relevant to the high ORR catalytic performance. A detailed c...