Abstract
Ferro-piezoelectricity occurs in robust and ordered crystalline materials, where polarization is reoriented under an external field. However, complex electric fields, disordered networks, and porous materials with poor crystallinity hinder the development of high-performance ferro-piezoelectric materials. Here, we describe two-dimensional (2D) crystalline Na-Mn-Sn-S chalcogels ([Sn(2)S(6)](4-):Mn(2+) at a molar ratio of 1:0.5; NMSC-1) with a unique arrangement within a disordered network, resulting in unprecedented intrinsic ferro-piezoelectric characteristics. The NMSC-1 can be used as an efficient filler in poly(vinylidene fluoride-trifluoro ethylene) [P(VDF-TrFE)]/NMSC-1 nanocomposite, enhancing crystallization of P(VDF-TrFE) and its ferro-piezoelectricity. Even at a low filler content of 0.5 wt %, the P(VDF-TrFE)/NMSC-1 nanocomposite exhibits superior piezoelectric performance compared with pure P(VDF-TrFE), P(VDF-TrFE)/other Na-Mn-Sn-S chalcogels (NMSC-2 and NMSC-3 with [Sn(2)S(6)](4-):Mn(2+) molar ratios of 1:1 and 1:2, respectively) with poor crystallinity, and nanocomposites of P(VDF-TrFE) and other 2D nanomaterials (Na-Mn-Sn-S powders, MgAl-layered double hydroxides, and SnS(2) nanoflowers), implying potential uses in sensing applications and the harvesting of mechanical energy.