A NiN3-embedded MoS2 monolayer as a promising electrocatalyst with high activity for the oxygen evolution reaction: a computational study

Abstract

The electrocatalytic oxygen evolution reaction (OER) plays a crucial role in the conversion of renewable electricity into storable fuels, for which the development of stable, low-cost, and efficient catalysts is highly crucial to boost the sluggish kinetics of the OER for achieving high efficiency. In this work, by means of comprehensive density functional theory (DFT) computations, we proposed a new class of OER catalyst, i.e., TMN₃@MoS₂, in which several TMN₃ moieties were embedded into a MoS₂ monolayer. Our results revealed that the introduction of N dopants can greatly enhance the binding strength between the TM atoms and MoS₂ monolayer, thus endowing them with excellent stability, which was further verified by ab initio molecular dynamics simulations, the dissolution potential, and diffusion barrier. In particular, according to the computed free energy changes, NiN₃@MoS₂ was revealed to exhibit the best catalytic OER activity due to its ultralow overpotential of 0.45 V. Interestingly, multiple-level descriptors, including the energy descriptor (ΔG_O* − ΔG_OH*) and structure descriptor (φ), involving the local structural and chemical environment of the reaction site can well rationalize the origin of the high catalytic activity of NiN₃@MoS₂ for the OER. Our findings not only open a new avenue to design OER catalysts with high stability, superior activity, and low cost, but also offer promising descriptors to accelerate the screening of alternative OER catalysts to the well-established noble Ru/Ir-based catalysts.