不同氧化程度氧化石墨烯/聚乙烯醇气凝胶对亚甲基蓝的吸附

氧化石墨烯(GO)对水中染料有着优异的吸附性能，但其氧化程度对复合材料吸附性能和机制的影响还未被充分研究。采用Hummer法，制备3种不同氧化程度的氧化石墨烯，与聚乙烯醇(PVA)复合得到三种GO/PVA气凝胶。利用红外光谱(FTIR)、元素分析(EA)和热重分析(TG)分析了3种GO的氧化程度；以亚甲基蓝(MB)为模拟污染物，通过静态吸附实验考察了GO氧化程度对GO/PVA气凝胶在不同溶液pH、吸附时间、初始浓度下对MB吸附性能的影响。通过吸附动力学模型、吸附等温线模型和吸附热力学模型探究了GO氧化程度对GO/PVA气凝胶吸附机制的影响。研究结果表明:GO/PVA气凝胶对MB的吸附行为受pH影响较小；提高GO的氧化程度可以明显提升GO/PVA气凝胶的吸附容量和吸附速度，GO氧化程度的提高增加了气凝胶上的吸附位点，有利于吸附。此外，GO氧化程度对GO/PVA气凝胶的吸附机制无明显影响。 

Adsorption of methylene blue by graphene oxide/polyvinyl alcoholaerogels with different oxidation degrees

Graphene oxide (GO) has excellent adsorption performance for dyes in water, but the effect of its oxidation degree on the adsorption performance and mechanism of composite materials has not been fully studied. Three kinds of graphene oxide (GO) with different oxidation degrees were synthesized by the Hummers and then compounded with polyvinyl alcohol (PVA) to synthesize three kinds of GO/PVA aerogels. The oxidation degree of GO was characterized by infrared spectroscopy (FTIR), elemental analysis (EA) and thermogravimetric analysis (TG). Using methylene blue (MB) as a simulated pollutant, the effect of GO oxidation degree of GO/PVA aerogels on MB adsorption performance under different solution pH, adsorption time and initial concentration was investigated through static adsorption experiments. The absorption mechanism of GO/PVA aerogels had been explored by adsorption kinetics model, model of adsorption isotherm and adsorption thermodynamic model. The results show that the adsorption behavior of GO/PVA aerogels on MB is slightly affected by pH. Increasing the oxidation degree of GO can significantly improve the adsorption capacity and adsorption speed of GO/PVA aerogels. And the adsorption sites on aerogel can be increase by improving the oxidation degree of GO , which is conducive to adsorption. In addition, the degree of GO oxidation has no obvious effect on the adsorption mechanism of GO/PVA aerogels.