Tunable Electronic and Optical Properties of a Planar Hydrogenated AsSi Hybrid Nanosheet: A Potential Wide Water-Splitting Photocatalyst

Abstract

Two-dimensional (2D) layered structures have recently drawn worldwide attention in material science and device physics because of their intriguing electrical and optical properties. In this paper, the structural, electronic, and magnetic properties of fully and partially hydrogenated AsSi nanosheets (NSs) are investigated by first-principles calculations based on density functional theory. Moreover, the potential as photocatalysts for water splitting is also studied. The results demonstrate that hydrogenated H atoms have a great influence on the electronic properties of the AsSi NS. By decorating their surface, fully and semihydrogenated AsSi NSs still exhibit ferromagnetism states and are predicated to be metallic or semiconductive depending on the surface coverage. Calculation results show that a more stable configuration of the semihydrogenated AsSi NS (AsSiH) is the one wherein all H atoms are adsorbed onto Si atoms, which is a semiconductor as the applied biaxial strains are from −6 to 9% and the band gap reaches its maximum with 4% tensile strain. More remarkably, AsSiH NSs with tensile strains up to 9% exhibit proper band gaps, valence, and conduction band positions of the reduction and oxidation levels in visible-light-driven water splitting. The diverse electronic and optical properties highlight hydrogenated AsSi NSs' potential applications in efficient electronic and optoelectronic devices.

Two‐Dimensional Silicon for (Photo)Catalysis

“…[ 46 ] The AsSi nanosheet was another candidate for this reaction. [ 47 ] It was demonstrated that AsSiH NSs with tensile strains up to 9% exhibit proper bandgaps, valence, and CB positions of the reduction and oxidation levels in visible light‐driven water splitting. [ 47 ]…”

Biaxial strain modulated the electronic structure of hydrogenated 2D tetragonal silicene

“…Hydrogenation can signicantly change the properties of 2D materials and is reported to have potential applications in spintronic devices. [26][27][28][29] Theoretical predictions have revealed hydrogenation is an effective method to tailor the electronic properties of 2D silicene-related materials, and some of them have been observed in the experiments. [30][31][32][33][34][35][36][37][38][39] Recent studies have reported fully hydrogenated silicene becomes wide band gap semiconductor and the type of gap depending on its atomic conformation, 31 whereas half hydrogenated silicene transforms to ferromagnetic semiconductor.…”