Su Heng, Zhang Chaocan, Li Xi, Wu Lili, Chen Yanjun
Department of Materials Science and Engineering, Wuhan University of Technology Wuhan 430070 China
Department of Chemical Engineering and Life Sciences, Wuhan University of Technology Wuhan 430070 China
RSC Adv. 2018 Nov 22;8(68):39140-39148. doi: 10.1039/c8ra07263a. eCollection 2018 Nov 16.
Graphene has attracted great interest due to its extensive applications in optoelectronic and electronic circuits and devices. However, reduction of graphene oxide (GO) to graphene is a process in which hydrophilic GO converts to hydrophobic graphene. Very little is known about the aggregation of graphene and the cause of performance degradation by general chemical reduction methods as the single reaction medium presents difficulty in satisfying the good dispersion of hydrophilic GO and hydrophobic graphene simultaneously. In this paper, we report a mixed medium of alkylphenol polyoxyethylene (7) ether (OP-7) and 2-methoxyethanol (EGM) for the preparation of graphene. The strong polar nature of EGM provides a good dispersion environment for GO, while the π-π interaction between the π-electrons in nonionic surfactant OP-7 aromatic ring structure and the π-electrons in graphene make the hydrophobic graphene well dispersed and prevent aggregation. Moreover, the reduction temperature is not high and the reduction time is short. The electrical conductivity of graphene without high-temperature treatment reached 14 000 S m. We have found the potential reduction mechanism of graphene and fundamentally solved the problem of aggregation. Our findings make it possible to process graphene materials using low-cost mixed medium processing techniques, providing a valuable reference for the large-scale preparation of graphene.
石墨烯因其在光电子和电子电路及器件中的广泛应用而备受关注。然而，氧化石墨烯（GO）还原为石墨烯是一个亲水性的GO转变为疏水性石墨烯的过程。对于石墨烯的聚集以及一般化学还原方法导致性能下降的原因知之甚少，因为单一反应介质难以同时满足亲水性GO和疏水性石墨烯的良好分散。在本文中，我们报道了一种用于制备石墨烯的烷基酚聚氧乙烯（7）醚（OP - 7）和2 - 甲氧基乙醇（EGM）的混合介质。EGM的强极性性质为GO提供了良好的分散环境，而非离子表面活性剂OP - 7芳环结构中的π电子与石墨烯中的π电子之间的π - π相互作用使疏水性石墨烯得以良好分散并防止聚集。此外，还原温度不高且还原时间短。未经高温处理的石墨烯的电导率达到了14000 S/m。我们发现了石墨烯潜在的还原机制并从根本上解决了聚集问题。我们的研究结果使得利用低成本混合介质加工技术处理石墨烯材料成为可能，为石墨烯的大规模制备提供了有价值的参考。
