Tunable hydrogen evolution activity of black antimony-phosphorus monolayers via strain engineering: a first-principles calculation

The HER activity and related electronic properties of monolayer binary V-V compound SbP under the biaxial strains are discussed by employing the first-principles calculations based on DFT. It is found that different compressive and tensile strains would modulate the Delta G(H*), epsilon(LUS) partial charge density affecting the HER activity, and band structures of phosphorene for electrocatalysis. Particularly, as the Delta G(H*) decreases, the HER activity of strained SbP is improved under the compressive strains. Importantly, in the condition of applying - 6% strain, the value of Delta G(H*) reduced to 0.27 eV and transfers to metallic feature. In the other conditions, the bandgaps of systems under strains are indirect semiconductors. Comparing with strained-free case, the larger partial charge density of epsilon(LUS) on the surface of SbP illustrates the more H adsorption sites for electrocatalysis. Moreover, the HER activity is related to the partial charge density of epsilon(LUS) rather than the epsilon(LUS) site. The presentation reveals that strain would effectively modulate the HER performances for electrocatalysis. It is expected to provide further understanding in practical applications.