石墨烯的巯基修饰二氧化硅材料的制备及其吸附Pb2+离子的性能研究

在制备二氧化硅包裹石墨烯材料(石墨烯@SiO2)的基础上,将其与N-[3-(三甲氧基硅基)丙基]乙二胺(AAPTES)反应制得了氨基化的石墨烯@SiO2(石墨烯@SiO2-NH2)。


摘  要:随着工业的快速发展,水污染逐渐成为了人们的心头之患,如何保护水资源成为人们日益所关注的内容。在已有的水体污染物中,金属离子尤为典型,而吸附是对其进行去除的一种良好方法,该方法的关键是吸附材料的制备。为了去除水中的Pb2+,本文在制备二氧化硅包裹石墨烯材料(石墨烯@SiO2)的基础上,将其与N-[3-(三甲氧基硅基)丙基]乙二胺(AAPTES)反应制得了氨基化的石墨烯@SiO2(石墨烯@SiO2-NH2),最后将石墨烯@SiO2-NH2在强碱条件下与二硫化碳反应制得了石墨烯@SiO2-NH-SH。利用红外光谱(FT-IR),扫描电子显微镜(SEM)对所制得的吸附材料石墨烯@SiO2-NH-SH进行了表征分析,并将最终制备的石墨烯@SiO2-NH-SH作为吸附剂,研究其对水体中Pb2+的吸附性能。考察了pH、Pb2+初始浓度和时间对吸附效果的影响,结果表明在pH为5.5时,该材料对Pb2+的吸附效果较好,且吸附过程符合准二级动力学方程,同时也可以较好地用Langmuir等温方程所描述。

关键词:石墨烯;二氧化硅;吸附;Pb2+

Preparation of the Thiol Modified Silica Materials Based on Graphene and Their Performance for Pb2+ Ion Adsorption

Abstract: With the development of industry, water pollution has become a serious problem and how to protect water resources has attracted more and more people's attention. Metal ion is especially typical in the existing water pollutants and adsorption is a good method to remove them. The key to this method is the preparation of adsorption material. For this purpose, a new adsorbent of graphene@SiO2-NH-SH was prepared in this paper by the reaction of amino modified graphene@SiO2 (graphene@SiO2-NH2) and carbon disulfide under the strong alkaline conditions. Before which, graphene@SiO2-NH2 was obtained by using the reaction of the pre-prepared graphene@SiO2 and N-[3-(three oxygen silicon-based) propyl] ethylenediamine (AAPTES). The prepared material was characterized by Fourier transform infrared spectrometry (FT-IR) and scanning electron microscopy (SEM). graphene@SiO2-NH-SH was then used for Pb2+ ions adsorption. The factors of solution pH, initial concentration of Pb2+ and adsorption time that influence the adsorption capacity were investigated. The results show that at pH 5.5, this material exhibited good performance for the adsorption of Pb2+. The adsorption process could be described by pseudo-second-order kinetic model and in line with the Langmuir isotherm model.

Key Words: Graphene; Silica; Adsorption; Pb2+ ions

目    录

摘  要 1

引  言 2

1 实验部分 3

1.1 仪器与试剂 3

1.2 实验方法 4

2 结果与讨论 6

2.1 材料的表征分析 6

2.2 溶液pH值的影响分析 7

2.3 吸附动力学分析 8

2.4 吸附等温线分析 9

3 结  论 10

参考文献 10

致  谢 13

基于石墨烯的巯基修饰二氧化硅材料的制备及其吸附Pb2+离子的性能研究

引 言

近年来世界工业活动快速增加,我国工业在快速发展的同时也带来了许多环境污染问题,政府及相关部门也为此积极制定了一些尤为严厉的政策。污染的河水中的重金属离子常来源自工业废水,例如:油漆染料、采矿、机械加工、毛皮加工、焊接、电解电镀、橡胶制作等工业废水,这些金属离子包括Te3+、Cd2+、Pb2+、Se6+等,这些废水的不断排放会导致水体中重金属离子浓度增加,从而会对水中植物和动物的生存产生影响,同时也会影响人民的身体健康。重金属离子对人体的危害极大,如日本水俣湾所发生的“水俣病”是由Hg2+中毒所引起,而我国曾经发生过的“血铅”事件也值得我们反思[1]。铅是一种可以在人体中富集的毒物,主要通过食入和吸入被人体吸收并在人体内不断的积累,对人体的肠道、神经、骨骼、酶等产生不可逆的损害。人体长期暴露在铅中可导致急性和慢性中毒,慢性铅中毒可能出现食欲不振和体重减轻等症状,其毒性具有长期的持续性。而急性的铅中毒会导致消化系统出现严重的损害,短期内可能对身体造成不可挽回的伤害[2-3]。所以,探究如何从环境水体及排放的污水中去除铅离子具有十分重要的意义。