Highly efficient dual-electrode exfoliation of graphite into high-quality graphene via square-wave alternating currents

Scalable production of high-quality graphene nanosheets is urgently needed to realize its practical applications. Here, we show that electrochemical dual-electrode exfoliation via alternating current can effectively produce high-yield solution-processable graphene. The selected molecule, tetrabutylammonium hydrogen sulfate, has the ability to diminish anodic oxidation damage to structures while also allowing for simultaneous intercalation of anion and cation species. Additionally, repeated intercalation of cations and anions with alternating current accelerates the ion intercalation and exfoliation process, leading to highly efficient graphene production with minimum destruction. After precisely controlling the intercalation process, high-yield graphene (88.6%) with uniform thickness distribution (77%, 1–3 layers) was achieved. Meanwhile, as-prepared graphene exhibits outstanding electrical conductivity (>6 × 104 S m−1), a considerably high C/O ratio of > 47.2, and a very low defect density (ID/IG < 0.045). Remarkably, the up-scaled manufacturing technique not only achieves a record high production rate (over 80 g h−1), but also improves upon the best-reported graphene quality and exfoliation efficiency (by > 60%). This rapid and scalable method will facilitate the widespread manufacture of high-quality graphene and open up a myriad of potential uses.