2D van der Waals (vdW) materials offer infinite possibilities for constructing unique ferroelectrics through simple layer stacking and rotation. In this work, we stack nonferroelectric GeS2 and ferroelectric CuInP2S6 to form heterostructures by combining sliding ferroelectric polarization with displacement ferroelectric polarization to achieve multiple polarization states. First-principles calculations reveal that the polarization reversal of the CuInP2S6 component in the GeS2/CuInP2S6/GeS2 heterostructure can simultaneously drive the switching of sliding ferroelectric polarization, displaying a robust coupling of the two polarizations and leading to the overall polarization switching. Based on this, ferroelectric arrays with a density of 6.55 × 1012 cm-2 (equivalent to a storage density of 0.7 TB cm-2) were constructed in a moiré superlattice, and the polarization strength of array elements was 11.77 pC/m, higher than that of all reported 2D vdW out-of-plane ferroelectrics. High den
Two-dimensional (2D) van der Waals (vdW) materials offer unprecedented possibilities for manipulating electrical and magnetic properties through layer twisting or sliding. In this study, we investigate the stack engineering of two magnetic monolayers, CrX3 (X = Cl, Br, I), by combining first-principles calculations and atomic spin dynamics simulations. The interlayer sliding of CrX3 bilayers disrupts space inversion symmetry, resulting in the emergence of ferroelectric polarization characterized by a low energy potential barrier and polarization reversal. Notably, as the halogen atoms change from Cl to I, the interlayer exchange interaction gradually intensifies, leading to a significant enhancement in both magnetic stability and ferroelectric polarization. Moreover, when a moiré superlattice is formed through small-angle twisting, the electrostatic moiré potential and magnetic exchange interaction coupling through layer stacking lead to the formation of staggered polarization domain
Two-dimensional (2D) layered materials have been widely used as catalysts due to their high specific surface area, large fraction of uncoordinated surface atoms, and high charge carrier mobility. Moiré superlattice emerges in 2D layered materials with twist angle or lattice mismatch. By manipulating the moiré superlattice structure, 2D layered materials present modulated electronic band structure, topological edge states, and unconventional superconductivity which are tightly associated with the performance of catalysts. Hence, engineering moiré superlattice structures are proposed to be an important technology in modifying 2D layered materials for improved catalytic properties. However, currently, the investigation of moiré superlattice structure in a catalytic application is still in its infancy. This perspective starts with the discussion of structural features and fabrication strategy of 2D materials with moiré superlattice structure. Afterward, the catalytic applications, inc