Tuning of magnetic, electronic and electrolytic water properties of silicene supported precious-metal by non-metal doping and vacancy defect

Abstract

It is well known that atomic adsorption or doping and surface defect can effectively modulate the physical properties and chemical activity of two-dimensional (2D) materials. In this paper, we systematically have explored the stability, electronic and magnetic properties of non-metal (NM = C, N, O, P, S, Se) doped vacancy-defect silicene, precious-metal (PM = Ru, Rh, Pd, Ag, Os, Ir, Pt, Au) doped vacancy-defect silicene, NM/PM co-doped vacancy-defect silicene, and the electrolytic water activity of stable PM single-atom doped systems using first-principles calculations based on density functional theory (DFT). By comparing the binding energy and electron localization functions (ELF) of the studied objects, it can be concluded that both NM-doped single-atomic vacancy (SV) silicene and double-atomic vacancy (DV) silicene have high stability, and the stability of NM-doped vacancy-defect silicene decreases with increasing the average bond length of Si-NM bond; the stability of PM-doped vacancy-defect silicene are stronger than that of the NM/PM co-doped vacancy-defect silicene. By comparing the free energy changes of hydrogen evolution reaction (HER) intermediate and oxygen evolution reaction (OER) intermediates, it can be concluded that Rh and Os-doped SV silicene have excellent HER activity, while Ir-doped DV silicene has good OER performance. Moreover, we also analyzed and discussed the electronic and magnetic properties of NM-doped vacancy-defect silicene, PM-doped vacancy-defect silicene and NM/PM co-doped vacancy-defect silicene, and we found that 109 PM doped systems out of 160 PM doped systems exhibit metallic properties, which is favorable for the development of vacancy-defect silicene supported PM single-atom in electrocatalytic field. Our study can provide theoretical support for the future development of the application value of vacancy-defect silicene.