Harnessing Supercritical CO 2 for Low‐Dimensional Materials: Fabrication and Application

ABSTRACT Supercritical carbon dioxide (SC CO 2 ), characterized by gas‐like diffusivity, liquid‐like solvating power, and near‐zero surface tension, has emerged as a high‐efficiency medium for the precision fabrication and functionalization of low‐dimensional nanostructures. This review systematically evaluates the progress in SC CO 2 ‐based synthesis over the past two decades, elucidating the fundamental mechanisms governing morphological and chemical evolution. Key methodologies are examined, beginning with the Supercritical Antisolvent‐Induced Polymer Epitaxy (SAIPE) mechanism, where tunable phase potentials enable the precise control of nucleation kinetics to achieve oriented polymer chain alignment on carbon nano‐tubes. For two‐dimensional (2D) materials, we analyze the physicochemical basis of SC CO 2 ‐assisted liquid‐phase exfoliation, highlighting how the “wedge‐expansion” effect and inverse micelle microenvironments drive high‐yield, low‐damage delamination. Furthermore, this work categorizes the strategies of structural regulation, including defect, strain, and phase engineering. The generated “chemical pressure” modulates atomic arrangements, lattice distortions, and electronic states to induce related properties. The diverse applications of these nanostructures in photoelectrocatalysis, energy conversion, and spintronics are discussed. Finally, an outlook on unresolved challenges regarding the understanding of microscopic mechanism and long‐term stability of induced metastable structures.