Strain Engineering for Phosphorene: The Potential Application as a Photocatalyst

TL;DR

This study explores how strain engineering can enhance phosphorene's potential as an efficient photocatalyst for water splitting, demonstrating stability, tunable band gaps, and improved optical properties through computational methods.

Contribution

It reveals the stability and enhanced photocatalytic properties of strained phosphorene, highlighting its potential for visible-light water splitting applications.

Findings

Phosphorene is stable under tensile strains but unstable under compression.

Tensile strain increases the band gap from 1.54 eV to 1.82 eV.

Strained phosphorene shows improved optical absorption for photocatalysis.

Abstract

Phosphorene has been attracted intense interest due to its unexpected high carrier mobility and distinguished anisotropic optoelectronic and electronic properties. In this work, we unraveled strain engineered phosphorene as a photocatalyst in the application of water splitting hydrogen production based on density functional theory calculations. Lattice dynamic calculations demonstrated the stability for such kind of artificial materials under different strains. The phosphorene lattice is unstable under compression strains and could be crashed. Whereas, phosphorene lattice shows very good stability under tensile strains. Further guarantee of the stability of phosphorene in liquid water is studied by ab initio molecular dynamics simulations. Tunable band gap from 1.54 eV at ambient condition to 1.82 eV under tensile strains for phosphorene is evaluated using parameter-free hybrid functional calculations. Appropriate band gaps and band edge alignments at certain pH demonstrate the potential application of phosphorene as a sufficiently efficient photocatalyst for visible light water splitting. We found that the strained phosphorene exhibits significantly improved photocatalytic properties under visible-light irradiation by calculating optical absorption spectra. Negative splitting energy of absorbed H2O indicates the water splitting on phosphorene is energy favorable both without and with strains.