Among emerging two-dimensional photocatalytic systems, van der Waals heterostructures based on graphitic carbon nitride (g-C₃N₄) and Janus transition metal dichalcogenides (TMDs) have attracted considerable attention for visible-light-driven hydrogen production. However, accurately identifying the energetically preferred interfacial configuration and understanding how structural distortions influence interlayer coupling remain significant challenges, limiting reliable prediction of photocatalytic performance and rational heterostructure design.
Here, we present a systematic first-principles density functional theory (DFT) investigation of flat and corrugated g-C₃N₄/PtSSe interfaces to assess their relative stability and elucidate the influence of structural corrugation on electronic and photocatalytic properties. Across all configurations examined, we find that corrugated heterostructures—rather than idealized planar interfaces—represent the true energetic ground state, exhibiting lower total energies and stronger interlayer binding. Further analysis reveals that corrugation modifies stacking registry and orbital overlap, enhancing interfacial charge redistribution and electronic coupling. Combined with the intrinsic out-of-plane dipole of the Janus PtSSe layer, this structural distortion promotes favorable band alignment and improved spatial separation of photogenerated carriers.
Our findings demonstrate that accurate structural modeling—including corrugation effects—is essential for reliably capturing interfacial stability and tunable photocatalytic activity in g-C₃N₄/Janus TMD heterostructures.