Serendipity for Topological Insulator as Multifunctional Electrocatalyst

Abstract

The design for multifunctional two-dimensional (2D) materials is considered as one of the main strategies to expand its application. Here, we propose that the already-synthesized organometallic lattice (Ni3(CNH)12) concurrently hosts topological and catalytic properties. Using first-principles calculations combined with tight-binding (TB) model, we demonstrate that the 2D Ni3(CNH)12 intrinsically possesses multiple Dirac cones along with flat bands passing through the Dirac bands. Taking the spin–orbital coupling (SOC) into account, all the degenerate points open gaps, spawning abundant topologically nontrivial insulating phases characterized by a nonzero Z2 topological invariant and edge states. Furthermore, because of its special geometry and electronic states, the 2D lattice can serve as a bifunctional electrocatalytic activity for overall water splitting with low overpotentials. Our current results offer a viable approach for the discovery of 2D organometallic materials with multifunctional application in spintronics devices and catalysts from the emerging field of topological materials.