Suppressing Oxygen\nAdsorption on Bulk Arsenic and\n2D Arsenic Nanoflake Surfaces: The Role of Sb Doping

The susceptibility of bulk and exfoliated nanolayered\narsenic to\noxidation has been a significant obstacle limiting their widespread\napplication and safe disposal. Here we report a controllable antimony-doped\n(Sb-doped) method via chemical vapor transport (CVT) with SnI<sub>4</sub> as a transport agent to prepare the bulk arsenic. After 96\nh of exposure to air, the oxygen content on the surface of Sb-doped\narsenic with SnI<sub>4</sub> is 67% lower compared to the undoped\narsenic with SnI<sub>4</sub>, and 89% lower than the control group\n(undoped arsenic without SnI<sub>4</sub>). Notably, Sb-doped arsenic\nis found to be easier and better exfoliated into two-dimensional (2D)\nnanoflakes with an average diameter of approximately 180 nm and a\nthickness of 4–5 nm. Sb doping reduces the surface oxygen content\nof exfoliated arsenic nanoflakes by 48% after 48 h of oxidation. Comprehensive\nexperimental investigations combined with first-principles calculations\ndemonstrate that the antioxidation improvements resulting from Sb-doping\nare due to the decreased adsorption energies of I<sub>2</sub> on the\n(012) and (003) surfaces of Sb-doped arsenic, while the adsorption\nenergies of O<sub>2</sub> increased compared to the corresponding\nsurfaces of undoped arsenic. The enhanced long-term stability in both\nbulk and layered Sb-doped arsenic presents a promising avenue for\nfurther advanced applications.