Soluble‐Salt‐Template Synthesis of Nanosheets With Tunable Two‐/Three‐Dimensional Architectures for Electrochemical Energy Storage and Conversion

Two-dimensional (2D) nanomaterials, characterized by unique electronic structures and anisotropic properties, have found diverse and promising applications in electrochemical energy storage and conversion. The spatial dimension, a critical structural factor of 2D nanomaterials, plays a key role in shaping their electrochemical performances. In various electrochemical reactions, 2D monodispersed and three-dimensional (3D) interconnected architectures exhibit differing advantages, yet both are essential for achieving optimal properties. Nevertheless, the compatible synthesis of 2D/3D architectures with analogous surface states remains a grand challenge for present nanosheet fabrication methods. The emerging soluble-salt-template method is prized for its flexibility in artificially controlling the 2D/3D spatial structures of the obtained homogeneous nanosheets. This work first provides a comprehensive summary of the dominant drying and conversion techniques employed in soluble-salt-template synthesis, unveils its mechanisms for modulating spatial dimensions and pore structures, and identifies critical process factors that significantly influence the final structural properties of the resulting products. Then, representative 2D/3D multiscale nanomaterials comprised of nanosheets using the soluble-salt-template method are categorized, and their potential applications in electrochemical energy storage and conversion are highlighted. Finally, we discuss existing technical hurdles, outline future research focuses, and explore new development trends for this specialized fabrication technology.