Graphene oxide (GO) is well known as a key material to the commercialization of graphene-based applications due to its excellent processability and abundant starting materials. However, producing high quality GO with excellent structural intactness still remains a challenge despite the significant research effort over the past decade. Herein, we demonstrate an effective approach to achieving well-oxidized GO within only 5 h of oxidation time at 5 °C or 25 °C from expanded graphite as a starting material. Our finding reveals that the well-oxidized GO synthesized at 25 °C can regain more graphitic sp2 networks and thus becomes as conductive as the GO prepared at 5 °C by means of thermal annealing or green chemical reduction. We also found that green chemical reduction using vitamin C (VC) is more efficient in restoring the electrical conductivity and reducing the defects in the GO produced at room temperature. The protocol reported in this paper offers a promising, sustainable way to fabricate high quality GO with minimal energy input, while being cost-effective.

中文翻译：

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快速且具有成本效益的室温合成具有优异结构完整性的高质量氧化石墨烯

氧化石墨烯（GO）由于其优异的加工性能和丰富的起始材料而被公认为是石墨烯应用商业化的关键材料。然而，尽管过去十年进行了大量研究，但生产具有出色结构完整性的高质量 GO 仍然是一个挑战。在此，我们展示了一种以膨胀石墨为起始材料，在 5°C 或 25°C 下，仅在 5 小时氧化时间内实现良好氧化的 GO 的有效方法。我们的发现表明，在 25°C 下合成的氧化良好的 GO 可以重新获得更多的石墨 sp2 网络，从而变得与通过热退火或绿色化学还原在 5°C 下制备的 GO 一样具有导电性。我们还发现，使用维生素 C (VC) 进行绿色化学还原在恢复导电性和减少室温下产生的 GO 缺陷方面更有效。本文报道的协议提供了一种有前途的、可持续的方式，以最少的能量输入制造高质量的 GO，同时具有成本效益。