The structural, electronic and catalytic properties of Au_n (n = 1–4) nanoclusters on monolayer MoS₂

摘要

The structural stability, electronic and catalytic properties of Au_n (n = 1–4) nanoclusters supported on monolayer MoS₂ have been investigated based on first principle DFT calculation with van der Waals (vdW) corrections. Our results show that all Au_n (n = 1–4) nanoclusters prefer to bind vertically on the top S sites of the monolayer MoS₂. And the relative stability of Au_n (n = 1–4) clusters in gas phase is not preserved after landing on monolayer MoS₂. By including van der Waals (vdW) corrections with different approaches, we found that the van der Waals correction increased the adsorption energies for all supported Au_n (n = 1–4) clusters with the order of E_ads(PBE-D2) > E_ads(PBE-D3) > E_ads(optB86b-vdW) > E_ads(PBE). And the van der Waals effects can also change the order of stability and the energy differences of various deposition configurations. In addition, the binding of O₂ is also modeled, showing significantly enhanced adsorption properties and catalytic activation toward O₂ adsorption, especially for that on supported Au₁ and Au₃ clusters with magnetic properties, with respect to that on supported Au₂ and Au₄ clusters with nonmagnetic properties. The current study provides further insight into the adsorption and catalytic properties of small gold clusters supported on monolayer MoS₂, which play a crucial role in the activation of O₂.