Spin‐Active Polarons Induced Nucleophilic Substitution on Fluorographene for In Situ Fabricating Distinctively 2D‐Based Bifunctional Nanocomposites

Nucleophilic substitution reaction (S_NR) plays a crucial role in traditional organic chemistry, and its extension into two dimensional (2D) materials has recently created a series of functional materials and advanced applications. However, the traditional S_NR process is usually indiscriminately copied into existing 2D reaction systems, which tremendously restricts the development of special 2D functional materials and sophisticated applications. In this work, a brand-new spin-active polarons-induced S_NR process in typical 2D fluorographene (FG) is proposed, where nucleophiles preferentially attack particular oxygen groups for functional grafting, simultaneously inducing the generation of spin-active polarons and subsequently rapid defluorination on the FG nanosheet. It is further revealed that the polarons are moderate but ongoing at low temperature and robust but short-lived at room temperature, respectively, no matter of the type of nucleophile. Finally, the particular spin-active polarons are regulated to fabricate a distinctively bifunctional and high-performance graphene-based nanofluid and self-sustained, moist-electric energy harvesting hydrogel with high and stable power generation (≈0.75 V, 4.5 µA, 33.6 mW m^-2) by an in situ polymerization-nanocomposite strategy. This work explores a unique 2D reaction process to break through the traditional S_NR process on 2D materials, which offers a broad avenue to fabricate novel 2D-based bifunctional materials and nanocomposites toward sophisticated applications.