Preparation of Face-Centered Cubic Fullerene Nanosheets via Liquid-Phase Exfoliation and Intercalation for Enhanced Photoelectrochemical Photodetectors

Fullerene (C₆₀) is considered to have great potential for the construction of high-performance electronic and photonic devices due to its highly conjugated molecular structure, high electron receptivity, and three-dimensional (3D) electron transport properties. We demonstrate a strategy for fabricating face-centered cubic (FCC) C₆₀ nanosheets stacked by van der Waals forces through liquid-phase exfoliation. This approach aims to further investigate the unique structure of the C₆₀ network and its potential applications in photoelectronics. Tetrabutylammonium hydroxide solution is utilized as the liquid-phase exfoliation (LPE) solvent to delaminate layered FCC C₆₀ crystals, resulting in FCC C₆₀ nanosheets (FC₆₀ NSs). The FC₆₀ NSs preserve the high crystallinity and FCC stacking structure of C₆₀ crystals, and their structure and physical properties can be modulated. Specifically, tetrabutylammonium ion (TBA⁺) intercalation is employed to adjust the band structure of FC₆₀ NSs. Compared with untreated FC₆₀ NSs, the performance of the TBA⁺ intercalated FCC C₆₀ nanosheets (I-FC₆₀ NSs)-based photoelectrochemical photodetector is significantly enhanced, with a responsivity (<i>R</i>) of 1.41 mA/W, detectivity (<i>D</i>*) of 2.18 × 10¹⁰ Jones, response time of <i>t</i>_r = 1.26 s, and <i>t</i>_d = 2.52 s. The characteristics of easy adjustment of the properties of this material are expected to be optimized for different fields, reflecting the great potential of FC₆₀ NSs in the development of optoelectronic materials.