氧化环境中氧化石墨烯的化学结构及性能变化研究

发布时间：2018-04-26 02:32

本文选题：氧化石墨烯 + 自由基　；参考：《东华大学》2017年硕士论文

【摘要】：石墨烯类纳米材料具有多种优良特性,已广泛应用于各种领域。近些年,随着氧化石墨烯(Graphene Oxide,GO)的规模化研究和应用,引发了人们对其潜在安全性和生态风险的关注,因而探索对之行之有效的去除技术十分必要。然而,在水环境领域,大多数研究都将GO当作光催化剂、吸附剂或载体等,而不是一种潜在污染物。本文选取了UV/H2O2、UV/过硫酸盐(Persulfate,PS)两种体系氧化GO,探索了两体系对GO化学结构和性能的影响。研究结果表明:(1)经两种体系氧化后得到的GO含氧官能团的量迅速减少。片状的GO在自由基攻击后碎裂成许多片段。在UV/PS氧化体系中,GO的矿化率达到81.2%,而在UV/H2O2体系中仅为13.8%,说明UV/PS体系可以更有效地降解甚至矿化GO,其有望成为去除水体中GO的有效手段。同时,本文证明在GO作载体或是催化剂应用于活化PS或单过氧硫酸氢盐(Peroxymonosulfate,PMS)产生硫酸根自由基时,其自身结构会发生改变。因此,在GO基复合材料应用于自由基为主的高级氧化体系时,需要特别关注材料的稳定性。(2)考虑到GO在UV/H2O2和UV/PS体系中结构和形貌会发生改变,研究了GO经这两种氧化体系处理后对亚甲基蓝(Methylene Blue,MB)的吸附性能变化情况。结果表明:经UV/H2O2和UV/PS体系氧化1 h后,GOs表面的含氧官能团数量就开始明显减少;对其进行动力学和热力学拟合表明该吸附过程更符合准二级动力学(R20.999)和Langmuir模型。在该模型下,经UV/H2O2和UV/PS分别氧化1、2、4 h后MB饱和吸附量依次为580.26、591.80、598.63、521.77、554.91和568.00 mg/g。经氧化处理后的GOs的吸附性能随着氧化时间的延长,会有所减弱,尤其在UV/PS体系中表现得更为显著。
[Abstract]:Graphene nanomaterials have been widely used in various fields because of their excellent properties. In recent years, with the large-scale research and application of graphene oxide oxide (GOO), attention has been paid to its potential safety and ecological risks, so it is necessary to explore effective removal technology. However, in the field of water environment, go is widely used as photocatalyst, adsorbent or carrier, rather than as a potential pollutant. In this paper, the oxidation of goo by UV / H _ 2O _ 2O _ 2 / PersulfatePS-persulfate system was studied, and the effects of the two systems on the chemical structure and properties of go were investigated. The results show that the oxygen content of go functional groups decreased rapidly after the oxidation of the two systems. The flake go is broken into many fragments after free radical attack. The mineralization rate of go reached 81.2 in UV/PS oxidation system and 13.8in UV/H2O2 system, indicating that UV/PS system can degrade or even mineralize goo more effectively, which is expected to be an effective means to remove go in water. At the same time, it is shown that when go is used as carrier or catalyst to activate PS or peroxymonosulfate PMSs to produce sulfate radical, its structure will change. Therefore, when go matrix composites are used in advanced oxidation systems dominated by free radicals, special attention should be paid to the stability of the materials.) it is considered that the structure and morphology of go in UV/H2O2 and UV/PS systems will change. The changes of adsorption properties of go for methylene blue methylene (MBB) after treatment with these two oxidation systems were studied. The results show that the number of oxygen functional groups on the surface of UV/H2O2 and UV/PS begins to decrease after oxidation for 1 h, and the kinetic and thermodynamic simulations show that the adsorption process is more in line with the quasi-second-order kinetic model R20.999) and the Langmuir model. Under this model, the saturated adsorption capacity of MB was 580.26591.80, 598.63521.77.71,554.91 and 568.00 mg / g, respectively, after oxidized by UV/H2O2 and UV/PS for 4 h. The adsorption properties of GOs treated by oxidation will weaken with the prolongation of oxidation time, especially in UV/PS system.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ127.11;X505

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