Zhang Daheng, Sasidharan Sankar, Shi Jiahao, Sasikala Devi Assa Aravindh, Su Jianhua, Huang Jinhai, Xia Zhenyuan
Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry & Molecular Engineering, East China University of Science & Technology, Shanghai 200237, P. R. China.
Department of Industrial and Materials Science, Chalmers University of Technology, Göteborg 41296, Sweden.
ACS Appl Nano Mater. 2023 Oct 31;6(21):19639-19650. doi: 10.1021/acsanm.3c03284. eCollection 2023 Nov 10.
Electrochemical synthesis has emerged as a promising approach for the large-scale production of graphene-based two-dimensional (2D) materials. Electrochemical intercalation of ions and molecules between graphite layers plays a key role in the synthesis of graphene with controllable thickness. However, there is still a limited understanding regarding the impact of intercalant molecules. Herein, we investigated a series of anionic species (i.e., ClO, PF, BF, HSO, CHSO, and TsO) and examined their wedging process between the weakly bonded layered materials driven by electrochemistry. By combining cyclic voltammetry, X-ray diffraction (XRD), and Raman spectroscopy, along with density functional theory (DFT) calculations, we found that stage-2 graphite intercalation compounds (GICs) can be obtained through intercalation of ClO, PF, or BF anions into the adjacent graphene bilayers. The anodic exfoliation step based on ClO-GIC in (NH)SO (aq.) resulted in the formation of bilayer-rich (>57%) electrochemically exfoliated graphene oxide (EGO), with a high yield (∼85 wt %). Further, the physicochemical properties of these EGO can be readily customized through electrochemical reduction and modification with different surfactants. This versatility allows for precise tailoring of EGO, making it feasible for energy and electronic applications such as electrodes in electrochemical capacitors and functional composites in wearable electronics.
电化学合成已成为大规模生产基于石墨烯的二维（2D）材料的一种有前景的方法。离子和分子在石墨层间的电化学插层在可控厚度石墨烯的合成中起着关键作用。然而，对于插层剂分子的影响仍了解有限。在此，我们研究了一系列阴离子物种（即ClO、PF、BF、HSO、CHSO和TsO），并考察了它们在电化学驱动下在弱键合层状材料间的楔入过程。通过结合循环伏安法、X射线衍射（XRD）和拉曼光谱，以及密度泛函理论（DFT）计算，我们发现通过将ClO、PF或BF阴离子插入相邻的石墨烯双层中可获得2阶石墨插层化合物（GICs）。基于ClO-GIC在（NH）SO（aq.）中的阳极剥离步骤导致形成富含双层（>57%）的电化学剥离氧化石墨烯（EGO），产率较高（约85 wt%）。此外，这些EGO的物理化学性质可通过电化学还原和用不同表面活性剂改性轻易定制。这种多功能性使得EGO能够被精确剪裁，使其在能量和电子应用中成为可行的选择，如电化学电容器中的电极以及可穿戴电子产品中的功能复合材料。
