Abstract

The freeze-drying or supercritical CO₂ drying methods are usually used to remove the solvent to keep the shape of material in traditional methods for preparing graphene foam. Porous frozen tofu is a kind of traditional Chinese food and prepared through a process of freezing casting and thawing. Inspired by it, a green and economic approach for graphene foam (GF) synthesis using one-step reduction and air-drying is reported in this article. By controlling the reduction time and precursor concentration, monolithic GF with a little or without volume shrinkage can be obtained after a simple pre-freezing, thawing, and air-drying step of the graphene hydrogel. The obtained GF shows low density (17.5 mg/cm³), superelastic, high recyclability, and excellent oil absorption ability. During the whole preparation process, the conditions were mild, and no special equipment such as freezer dryer was used, which is beneficial to large-scale production of porous GF with high oil adsorption and recyclability.

One-step green reduction and air-drying method was used to synthesis graphene foam and it exhibited excellent oil–water separation ability.

中文翻译：

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通过一步还原和风干制备油水分离石墨烯泡沫

摘要

在制备石墨烯泡沫的传统方法中，通常使用冷冻干燥或超临界CO ₂干燥方法去除溶剂以保持材料的形状。多孔冻豆腐是一种中式传统食品，是通过冷冻浇铸和融化的过程制备的。受此启发，本文报道了一种采用一步还原和风干的绿色经济的石墨烯泡沫（GF）合成方法。通过控制还原时间和前体浓度，可以在简单的石墨烯水凝胶预冷冻，解冻和风干步骤后，获得体积收缩很少或没有体积收缩的整体式GF。所得的GF显示低密度（17.5 mg / cm ³），超弹性，高可回收性和优异的吸油能力。在整个制备过程中，条件温和，没有使用冷冻干燥机等专用设备，有利于大规模生产具有高吸油性和可回收性的多孔GF。

一步法绿色还原和风干法用于合成石墨烯泡沫，它具有出色的油水分离能力。