Herein, an efficient, facile, scalable production of graphene dispersions via exfoliation of graphite in an environment-friendly PVA/H₂O solvent system is reported. To warrant the impact of processing parameters on exfoliation efficiency, a systematic investigation is carried out using UV–visible spectroscopy. Under the optimal shearing parameters (1 h, 10 k rpm) with the PVA-to-fed graphite mass ratio of 10, a high concentration graphene dispersion (3.36 mg mL⁻¹) is achieved. The estimated graphene yield is found to be 33% that further increases to 90% after sediment recycling. With the aim of detailed quality analysis, centrifugal cascading is adopted to predominately sort the graphene flakes from the upper end of the distribution. Through various characterization techniques, it is confirmed that the resulting dispersion comprises high-quality graphene flakes (1–5 layers) having thickness up to 1.48 nm, lateral dimension ranging from 0.3 to 4 µm, and quite a low level of defects (I_D/I_G = 0.1). The statistical distribution histogram reveals that most flakes are single-layer (41%), including some bi-layer (21%) and tri-layer (28%), while the remaining can be said five or multi-layer graphene. Meanwhile, the efficacy of the PVA/H₂O solvent system is also demonstrated using ultrasonic exfoliation, providing a high concentration of graphene (1.1 mg mL⁻¹) in a relatively short time (8 h). Furthermore, the applicability of the PVA-stabilized graphene dispersion is addressed by fabricating various graphene products such as graphene paper electrodes, graphene composites, and graphene thin films. Impressively, the graphene paper electrode imparts an exceptionally high specific capacitance of 199.63 F g⁻¹ in a potential window range of 0 to 2 V, and hence could be a promising alternative to traditional electrodes in supercapacitors. Conclusively, the exfoliation of graphite in a green polymer–solvent system offers to produce highly concentrated graphene dispersions at a minimal cost that could be widely applicable in different research areas, thus holding the potential for commercial viability.

本文报道了通过在环境友好的 PVA/H ₂ O 溶剂系统中剥离石墨来高效、简便、可扩展地生产石墨烯分散体。为了保证加工参数对剥离效率的影响，使用紫外-可见光谱进行了系统研究。在最佳剪切参数（1 小时，10 k rpm）下，PVA 与进料石墨的质量比为 10，高浓度石墨烯分散体（3.36 mg mL ^-1） 已完成。发现估计的石墨烯产量为 33%，在沉积物回收后进一步增加到 90%。为了进行详细的质量分析，采用离心级联从分布的上端对石墨烯薄片进行主要分选。通过各种表征技术，可以确认，所得到的分散体包含具有厚度最大为1.48纳米的高质量石墨烯薄片（1-5层），横向尺寸为0.3至4微米，并且缺陷相当低的水平（我_d /我_ģ = 0.1）。统计分布直方图显示，大多数薄片是单层（41%），包括一些双层（21%）和三层（28%），而其余的可以说是五层或多层石墨烯。同时，PVA/H ₂ O 溶剂系统的功效也通过超声波剥离得到了证明，可在相对较短的时间内（8 小时）提供高浓度的石墨烯（1.1 mg mL ^-1）。此外，通过制造各种石墨烯产品，如石墨烯纸电极、石墨烯复合材料和石墨烯薄膜，解决了 PVA 稳定石墨烯分散体的适用性。令人印象深刻的是，石墨烯纸电极具有 199.63 F g ^{-1 的}超高比电容在 0 到 2 V 的电位窗口范围内，因此可能是超级电容器中传统电极的有前途的替代品。最后，在绿色聚合物-溶剂系统中剥离石墨可以以最低的成本生产高浓度的石墨烯分散体，可广泛应用于不同的研究领域，从而具有商业可行性的潜力。