中文摘要：

基于改进Hummers法,调控氧化剂KMnO4用量制备了不同含氧官能团含量的氧化石墨烯（GOs）。采用XRD、XPS、AFM和FTIR分析了KMnO4用量对GOs的结构特征、含氧官能团类型及含量的影响,研究了氧化程度对GOs吸附亚甲基蓝（MB）性能的影响。结果表明：KMnO4用量对GOs-n（n=2,3,4）的含氧官能团类型和含量有显著影响;MB最大饱和吸附量依次为728.44、965.63和807.29 mg·g^-1,与Langmuir模型单分子层饱和吸附量的标准差为3.6%、3.7%和4.2%,吸附动力学过程符合准二级动力学模型,R^2〉0.99。以GOs结构层上去质子化的羟基（—C—O--）和羧基（—COO--）为主要活性位点与MB发生化学控速的单分子层放热吸附,吸附热在20-27 kJ·mol^-1之间;低氧化程度的GOs以离子交换吸附为主导,吸附性能与GOs结构中—C—O（H）和—COO（H）的总量呈正相关。随氧化程度加深,GOs结构中环氧基（C—O—C）和羰基（C═O）以氢键作用吸附MB对吸附量的影响凸显。

英文摘要：

Graphene oxide（GOs） with different oxygen-containing functional groups was prepared by adjusting the amount of oxidant KMnO4. The effects of KMnO4 dosage on the structural characteristics, the type and content of the functional groups of GOs were analyzed by XRD, XPS, AFM and FTIR, and the performance of GOs on methylene blue（MB） were studied. The results indicated that KMnO4 dosage has a significant effect on the oxidation degree of GOs-n（n = 2, 3, 4）, the maximum saturated adsorption capacity of MB-＋ was 728.44、965.63 and 807.29 mg·g^-1, compared with Langmuir model fitted values of single molecular layer saturated adsorption capacity of standard deviation was 3.6%, 3.7% and 4.2%, respectively. Pseudo-second-order kinetic model could better describe the dynamic process of adsorption, and R^2 0.99, which based on GOs structure on the most abundant hydroxyl（—C—O^-） and carboxyl（—COO^-） as the main active sites with MB-＋ occur single molecular layer, exothermic and chemical speed control process. Adsorption heat was between 20—27 k J·mol^-1, and adsorption mechanism was dominated by ion exchange adsorption. Adsorption performance was positively correlated with the total amount of —C—O--and —COO--in GOs structure. Effects of epoxy groups and carbonyl groups on the adsorption capacity of MB by hydrogen bonding become prominent with increasing the extent of oxidation.