Li Chen, Lu Yanling, Yan Jun, Yu Weibo, Zhao Ran, Du Shiguo, Niu Ke
Army Engineering University of People's Liberation Army, Shijiazhuang Campus, No. 97 Heping West Road of Shijiazhuang, Shijiazhuang, Hebei province 050003, People's Republic of China.
Institute of Chemical Defence, Academy of Military Science, Zhijiang, Hubei province 443200, People's Republic of China.
R Soc Open Sci. 2021 Dec 8;8(12):202309. doi: 10.1098/rsos.202309. eCollection 2021 Dec.
After long-term ageing, the structure of graphene oxide prepared by the modified Hummers method changed. Because of the desorption of oxygen-containing functional groups, the C/O ratio of graphene oxide increased from 1.96 to 2.76. However, the average interlayer distance decreased from 0.660 to 0.567 nm. The content of -CH- and -CH- decreased; however, the type of oxygen-containing functional groups did not change. Moreover, / increased from 0.87 to 0.92, indicating that the defect density decreased because of desorbing oxygen functional groups after ageing. When the temperature exceeded 60°C, CO produced by decomposing graphene oxide was detected. The thermal decomposition changed after ageing. The decomposition peak temperature decreased from 216°C to 195°C. The CO amount produced remained almost unchanged; however, the amount of CO, SO and HO decreased. After ageing, the apparent activation energy of graphene oxide decreased from 150 to 134 kJ mol.
经过长期老化后，采用改进的Hummers法制备的氧化石墨烯结构发生了变化。由于含氧官能团的脱附，氧化石墨烯的C/O比从1.96增加到2.76。然而，平均层间距从0.660减小到0.567nm。-CH-和-CH-的含量降低；然而，含氧官能团的类型没有改变。此外，/从0.87增加到0.92，表明老化后由于含氧官能团的脱附，缺陷密度降低。当温度超过60°C时，检测到由氧化石墨烯分解产生的CO。老化后热分解发生了变化。分解峰值温度从216°C降至195°C。产生的CO量几乎保持不变；然而，CO、SO和HO的量减少了。老化后，氧化石墨烯的表观活化能从150kJ/mol降至134kJ/mol。
