The effects of substitutional doping on Cu vacancy formation in Cu₂O(111): a density functional theory study

Abstract

Using density functional theory (DFT) calculations, we examine the effect of substitutional doping on the formation of Cu vacancies in Cu2O(111). Upon replacing coordinatively-unsaturated O with other elements (N, F,...

Understanding the role of Cl doping in the oxygen evolution reaction on cuprous oxide by DFT

“…This is because a Cl atom has a larger atomic radius than an O atom and will push Cu CSA away, which is consistent with previous research results. 36 Cl doping leads to a large strain on Cu 2 O(111), which facilities the formation of a Cu vacancy. The Cu vacancy formation energies of pristine Cu 2 O(111) and Cl–Cu 2 O(111) are shown in Table 1.…”

“…The reason why we chose O SUF was that the O vacancy was more favored at this site based on Beronio et al's results. 36 Then, Cu CUS was removed to form vacancies from Cl-Cu 2 O(111) to simulate V Cu -Cl-Cu 2 O(111) because Cu CUS vacancies were more favored than Cu CSA on Cl-Cu 2 O(111). 35,36 For all the calculations, the top two layers of the slab were allowed to relax until the force on the atoms was converged to 0.02 Ev Å À1 , while the remaining bottom three layers were fixed.…”

“…Cu CUS was removed to form vacancies from Cu 2 O(111) to simulate V Cu –Cu 2 O(111) since Cu CUS vacancies were easily formed on Cu 2 O(111). 36 Based on Cu 2 O(111), the O SUF in the uppermost layer was replaced with one Cl atom to simulate Cl–Cu 2 O(111) and the doping level of Cl was approximately 0.83 at %. The reason why we chose O SUF was that the O vacancy was more favored at this site based on Beronio et al 's results.…”

“…32,33 For example, the defects of electrocatalysts have a significant impact on the OER performance. 34 Because the coordinatively unsaturated copper vacancies (V Cu ) are expected to form in the Cu 2 O surface and Cl-doped Cu 2 O surface, 35,36 we also consider the effect of surface defects before and after Cl doping. Four kinds of Cu…”

“…32,33 For example, the defects of electrocatalysts have a significant impact on the OER performance. 34 Because the coordinatively unsaturated copper vacancies (V Cu ) are expected to form in the Cu 2 O surface and Cl-doped Cu 2 O surface, 35,36 we also consider the effect of surface defects before and after Cl doping. Four kinds of Cu 2 O surface models are established to be compared, including the pristine Cu 2 O(111), Cu 2 O(111) with V Cu (V Cu –Cu 2 O(111)), Cl-doped Cu 2 O(111) (Cl–Cu 2 O(111)) and Cl–Cu 2 O(111) with V Cu (V Cu –Cl–Cu 2 O(111)).…”