Le Hon Nhien, Luu Thi Bich Duyen, Pham Lam Nhu, Dao Thi Bang Tam, Nguyen Trung Do, Ha Thuc Chi Nhan, Le Van Hieu
Faculty of Materials Science and Technology, VNUHCM University of Science; Vietnam National University, Ho Chi Minh City (VNUHCM);
Faculty of Materials Science and Technology, VNUHCM University of Science; Vietnam National University, Ho Chi Minh City (VNUHCM).
J Vis Exp. 2025 Jul 3(221). doi: 10.3791/68313.
This present work describes the scalable synthetic methods of oxidation and reduction reactions for producing graphene oxide and reduced graphene oxide nanomaterials. Cascade design of Mn(VII)-based oxidation reaction is applied to convert graphite into multilayer graphite oxide powder, the precursor of single-layer graphene oxide nanosheets. Since exothermic heats, relevant chemical ratios, and combinative strategy are utilized, the cascade design process saves considerable amounts of heating energy, chemical reagents, and synthetic time. In the next stage, the hydrated multilayer structure of graphite oxide is exfoliated in water with the support of sonication. Graphene oxide nanosheets are electrostatically stabilized and chemically reduced using highly basic ammonia solution at pH >11 and a temperature of 90 °C. Alkaline ammonium hydroxide solution is considered an environmentally friendly and inexpensive chemical agent for synthesizing reduced graphene oxide nanosheets assembled in a hydrogel structure. Hydrated reduced graphene oxide nanosheets in the supramolecular hydrogel can be ultrasonically exfoliated to produce homogeneous aqueous dispersions. The general protocol of oxidation-reduction reactions sequentially synthesizes graphite oxide powder, graphene oxide nanosheet, reduced graphene oxide hydrogel, and reduced graphene oxide nanosheet for various scientific research and multidisciplinary applications. Prospective development of the synthetic approach from laboratory scale to industrial production is envisioned to elaborate on the potential.
本工作描述了用于制备氧化石墨烯和还原氧化石墨烯纳米材料的氧化和还原反应的可扩展合成方法。基于锰（VII）的氧化反应的级联设计用于将石墨转化为多层氧化石墨粉末，即单层氧化石墨烯纳米片的前体。由于利用了放热、相关化学比例和组合策略，级联设计过程节省了大量的加热能量、化学试剂和合成时间。在下一阶段，在超声处理的支持下，氧化石墨的水合多层结构在水中剥离。氧化石墨烯纳米片在pH>11和90°C的温度下，使用高碱性氨溶液进行静电稳定和化学还原。碱性氢氧化铵溶液被认为是一种环境友好且廉价的化学试剂，用于合成组装在水凝胶结构中的还原氧化石墨烯纳米片。超分子水凝胶中的水合还原氧化石墨烯纳米片可以通过超声剥离以产生均匀的水分散体。氧化-还原反应的通用方案依次合成氧化石墨粉末、氧化石墨烯纳米片、还原氧化石墨烯水凝胶和还原氧化石墨烯纳米片，用于各种科学研究和多学科应用。设想了从实验室规模到工业生产的合成方法的前瞻性发展，以阐述其潜力。
