ON–OFF Switching Modulation of the Hydrogen Evolution Reaction via Interlayer Sliding in Defect-Induced Graphene

Theoretical investigations have demonstrated that nonferroelectric two-dimensional (2D) graphene-like g-C3N4 bilayers can acquire sliding-induced ferroelectricity through specific stacking configurations, a phenomenon not observed in monoelemental systems like pure graphene bilayers, where inversion symmetry remains preserved under arbitrary sliding vectors. Inspired by vacancy defects in g-C3N4 monolayers, our first-principles calculations demonstrate that introducing vacancy defects into graphene monolayers (termed D-graphene) enables the emergence of interlayer sliding-induced and ferroelectro–antiferroelectric switching behavior. The weak interlayer coupling facilitates precise control of dipole alignment between adjacent layers through lateral displacement, enabling reversible transitions between ferroelectric and antiferroelectric ordering, inducing significant changes in the surface atomic arrangement and electronic structure. This dynamic interplay establishes an “ON–OFF” ferroelectric switching mechanism that regulates catalytic activity for the hydrogen evolution reaction (HER) via polarization-dependent modulation of reactant adsorption strength and activation barriers. Notably, the antiferroelectric D-graphene bilayer demonstrates Janus-type and bidirectional HER regulation and serves as a ferroelectric switch for catalytic process control. In contrast, ferroelectric g-C3N4 bilayers exhibit multistage HER enhancement during interpolarization switching, enabling the design of an “ON–OFF–ON” ferroelectric triple control system. These findings pave the way for a novel paradigm for electrocatalytic switch engineering through sliding-mediated ferroic order manipulation in van der Waals bilayers.