Regenerative Polyphenolic Free‐Standing Conductive Film

ABSTRACT Free‐standing, 2D conductive films are typically fabricated using inherently conductive materials such as graphene and carbon nanotubes. In contrast, approaches utilizing electrically non‐conductive precursors that self‐assemble into 2D materials prior to carbonization remain rare. Inspired by the traditional repeatable formation of tofu‐skin, we hypothesized that interfacial self‐assembly could enable continuous regeneration of thin films at the air/water interface, thereby allowing scalable production. Here, we report a scalable strategy for fabricating free‐standing conductive films by exploiting the spontaneous interfacial assembly of polyphenol–amine complexes. Upon mixing pyrogallol and polyethyleneimine, thin interfacial films spontaneously form via oxidative crosslinking, and the film formation exhibits regenerative properties when it is removed. This behavior persists without agitation or replenishment until reactive components are depleted. The assembled films were carbonized into robust, free‐standing graphitic structures. Collectively, materials that are initially non‐conductive, yet capable of self‐assembly, spontaneous regeneration, and transformation into free‐standing conductive films upon carbonization, are exceptionally uncommon. Among tested formulations, films with optimized composition exhibited reduced defect density (I D /I G ≈ 0.9). These films maintained mechanical integrity and demonstrated conductivity sufficient to power an LED. This approach enables scalable production of graphitic films from natural, non‐conductive precursors.