弹性石墨烯气凝胶的制备及对含油污水的吸附

Preparation of elastic graphene aerogel and its adsorption on oily waste water

摘要:

采用冰模板和两步水热还原的方法通过常压干燥制备了石墨烯气凝胶（RGA）。利用SEM观察RGA的微观形貌，用XRD、XPS、FTIR和Raman对氧化石墨（GO）的还原情况进行分析。用电子万能试验机对RGA进行压缩回弹实验，结果证明RGA具有优异的压缩回弹性能（在50%应变下压缩回弹200次后RGA仍能迅速回弹至原始高度，且外形和高度没有明显变化）。模拟含油污水吸附性能测试表明，RGA经过210 min的吸附即可趋于吸附平衡，其对水中乳化油的吸附量达到1466.325 mg·g-1；RGA对含油污水的吸附动力学模型符合准二级动力学模型；内扩散模型表明RGA对含油污水的吸附分为RGA表面的大孔扩散、内部的中孔扩散和微孔扩散三个阶段；循环吸附结果表明RGA对含油污水具有优异的循环吸附性能（循环吸附15次的吸附量均保持在1400~1450 mg·g-1）；对实际污水的吸附结果表明，RGA对实际污水的去除率可以达到90%以上，并且可以循环使用。

Abstract:

Graphene aerogels (RGA) were prepared by ice template and two-step hydrothermal reduction through atmospheric drying. The microstructure of RGA was observed by SEM, and the reduction of graphene oxide (GO) was analyzed by XRD, XPS, FTIR and Raman. The electronic universal testing machine was used to carry out the compression spring back experiment on RGA, and the results showed that RGA had excellent compression spring back energy (under 50% strain, after 200 times of compression spring back, RGA could still bounce back to the original height quickly, without significant changes in shape and height). The adsorption performance test of simulated oily waste water showed that RGA tended to adsorption equilibrium after 210 minutes of adsorption, and the adsorption capacity of RGA to emulsified oil in water reached 1466.325 mg·g-1. The adsorption kinetic model of RGA on oily waste water conforms to the quasi-second-order kinetic model. The internal diffusion model showed that the adsorption of oily waste water by RGA was divided into three stages: macropore diffusion on the surface of RGA, mesopore diffusion and micropore diffusion. The cyclic adsorption results showed that RGA had excellent cyclic adsorption performance on oily waste water (the adsorption capacity of the cyclic adsorption of 15 times was kept between 1400 and 1450 mg·g-1). The adsorption results of the actual sewage show that the removal rate of the actual sewage by RGA can reach more than 90%, and can be recycled.