Halogen Edge-Passivated Antimonene Nanoribbons for Photocatalytic Hydrogen Evolution Reaction with High Solar-to-Hydrogen Conversion

The photocatalytic hydrogen evolution reaction (HER) by the antimonene nanoribbon with the halogen edge passivation is investigated with the first-principles density functional theory calculations. Both the armchair and zigzag structures (represented by aSbNR_X/zSbNR_X; X = F, Cl, Br, and I) are fully relaxed, and the stability is confirmed by the ab initio molecular dynamics. The electronic and optical properties, together with the carrier mobility, the solar-tohydrogen energy conversion efficiency (eta(STH)), and the Gibbs free energy, are determined to examine the photocatalytic performance. The results demonstrate that both the valence band maximums and conduction band minimums of aSbNR_X and zSbNR_F match the redox potentials of the water-splitting HER for the hydrogen generation, although the valence band maximums of zSbNR_Cl/Br/I are out of the condition. The nanoribbons with hydrogen edge passivation have also been investigated as a contrast to confirm the effect of the halogen edge passivation on the electronic properties of the antimonene nanoribbons. The results demonstrate that all the considered antimonene nanoribbons possess apparent optical absorptions in the visible and ultraviolet light regions. The obvious tuning effect of the strain engineering on band edges and band gaps is also observed. Under the tensile strain larger than 4%, all the present antimonene nanoribbons can satisfy the redox potentials for the water-splitting HER. Remarkably, the tensile strain can promote.STH, and the maximum value can reach the theoretical limit of 17.51% under the tensile strain of 12%. The change of the Gibbs free energy for HER is approximately 0.65 eV. These results indicate that the newfound nanoribbons can be preferable candidates for the solar light photocatalytic water splitting for hydrogen production.

Automated summary

The photocatalytic hydrogen evolution reaction by antimonene nanoribbon with halogen edge passivation shows enhanced performance under tensile strain larger than 4%, and the different halogen edges have varying effects on the electronic properties. The nanoribbons with hydrogen edge passivation exhibit valence band and conduction band maximums matching the redox potentials for water-splitting HER, indicating their potential as preferable candidates for solar light photocatalytic water splitting for hydrogen production.