First-Principle Study of Two-Dimensional SiP2 for Photocatalytic Water Splitting with Ultrahigh Carrier Mobility

Abstract

Two-dimensional materials present abundant novel properties when used in advanced applications, which develops considerable focus. In this investigation, the first-principles calculations are explored to study the structural characteristic of the monolayered SiP2, which is stable even at 1200 K. The SiP2 monolayer is a semiconductor with an indirect bandgap of 2.277 eV. The decent band alignment and light absorption capacity imply that the application is a suitable photocatalyst for water splitting. Furthermore, the SiP2 monolayer possesses an ultrafast electron mobility at 33,153 cm2·V−1·s−1 in the transport direction. The excellent Gibbs free energy of the SiP2 monolayer is also addressed in an examination of the hydrogen evolution reaction.