Electrochemical Synthesis of 2D Polymeric Fullerene for Broadband Photodetection.

2D polymeric fullerene scaffolds, composed of covalently bonded superatomic C nanoclusters, are emerging semiconductors possessing unique hierarchical electronic structures. Hitherto their synthesis has relied on complex and time-consuming reactions, thereby hindering scalable production and limiting the technological relevance. Here, the study demonstrates a facile electrochemical exfoliation strategy based on the intercalation and expansion of a layered fullerene superlattice, to produce large size (≈52.5 µm) and monolayer thick 2D polymeric C with high exfoliation yield (≈83%). In situ reduction of solvated protons (H) weakens the interlayer interactions thereby promoting the rapid and uniform intercalation of tetra-n-butylammonium (TBA), ensuring gram-scale throughput and high structural integrity of exfoliated 2D polymeric C. As a proof of concept, the solution-processed 2D polymeric C nanosheets have been integrated into thin-film photodetectors, exhibiting a broad spectral photoresponse ranging from 405 to 1200 nm, with a peak photocurrent at 850 nm and a stable response time. This efficient and scalable exfoliation method holds great promise for the advancement of multifunctional composites and optoelectronic devices based on 2D polymeric C.