Abstract It still remains a challenge to explore facile, economic, and environmental friendly process for the fabrication of graphene aerogels with low density and high purity to meet the various applications. Herein, arbitrary-shaped reduced graphene oxide (rGO) aerogels are prepared by freeze-drying process and followed unsaturated water vapor reduction method staring from GO aqueous suspensions for the first time. Water vapor hydrothermal treatment can decompose all oxygen-containing functional groups in GO and repair GO surface defects effectivly. At higher temperatures (≥175 °C), the carbon in GO may react with water vapor via water-gas shift reaction to form CO, which could also be used as the reductant for the reduction of GO aerogels. The water volume as well as the temperature are key parameters for realizing high reduction degree as well as good shape control of rGO aerogels. Arbitrary shaped rGO aerogels could be prepared by using various molds for freezing GO suspensions. rGO aerogels exhibit a high oil/water separation performance, which could absorb various oils up to 40-55 times of its initial weight with high recyclability. Moreover, the rGO aerogels exhibit typical pressure sensing behavior and excellent energy storage capacitance, which hold great potential applications in flexible pressure sensors and supercapacitors.

中文翻译：

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通过不饱和水蒸气还原任意形状的还原氧化石墨烯气凝胶

摘要 探索简便、经济、环保的制备低密度、高纯度石墨烯气凝胶以满足各种应用的工艺仍然是一个挑战。在此，首次从 GO 水悬浮液开始，通过冷冻干燥工艺和不饱和水蒸气还原法制备任意形状的还原氧化石墨烯 (rGO) 气凝胶。水蒸气水热处理可以分解GO中的所有含氧官能团，有效修复GO表面缺陷。在较高温度（≥175°C）下，GO 中的碳可以通过水煤气变换反应与水蒸气反应形成 CO，CO 也可用作还原 GO 气凝胶的还原剂。水量和温度是实现 rGO 气凝胶的高还原度和良好形状控制的关键参数。可以通过使用各种模具冷冻 GO 悬浮液来制备任意形状的 rGO 气凝胶。rGO气凝胶具有较高的油水分离性能，可吸附各种油类，吸附量可达其初始重量的40-55倍，且具有较高的可回收性。此外，rGO气凝胶表现出典型的压力传感行为和优异的储能电容，在柔性压力传感器和超级电容器中具有巨大的应用潜力。吸油量可达其初始重量的40-55倍，具有很高的可回收性。此外，rGO气凝胶表现出典型的压力传感行为和优异的储能电容，在柔性压力传感器和超级电容器中具有巨大的应用潜力。吸油量可达其初始重量的40-55倍，具有很高的可回收性。此外，rGO气凝胶表现出典型的压力传感行为和优异的储能电容，在柔性压力传感器和超级电容器中具有巨大的应用潜力。