Savazzi Filippo, Risplendi Francesca, Mallia Giuseppe, Harrison Nicholas M, Cicero Giancarlo
Dipartimento di Scienza Applicata e Tecnologia , Politecnico di Torino , Corso Duca degli Abruzzi 24 , Torino 10129 , Italy.
Department of Chemistry , Imperial College London , South Kensington , London SW7 2AZ , United Kingdom.
J Phys Chem Lett. 2018 Apr 5;9(7):1746-1749. doi: 10.1021/acs.jpclett.8b00421. Epub 2018 Mar 22.
Graphene oxide (GO) is a versatile 2D material whose properties can be tuned by changing the type and concentration of oxygen-containing functional groups attached to its surface. However, a detailed knowledge of the dependence of the chemo/physical features of this material on its chemical composition is largely unknown. We combine classical molecular dynamics and density functional theory simulations to predict the structural and electronic properties of GO at low degree of oxidation and suggest a revision of the Lerf-Klinowski model. We find that layer deformation is larger for samples containing high concentrations of epoxy groups and that correspondingly the band gap increases. Targeted chemical modification of the GO surface appears to be an effective route to tailor the electronic properties of the monolayer for given applications. Our simulations also show that the chemical shift of the C-1s XPS peak allows one to unambiguously characterize GO composition, resolving the peak attribution uncertainty often encountered in experiments.
氧化石墨烯（GO）是一种多功能二维材料，其性质可通过改变附着在其表面的含氧官能团的类型和浓度来调节。然而，关于这种材料的化学/物理特性对其化学成分的依赖性的详细知识在很大程度上尚不清楚。我们结合经典分子动力学和密度泛函理论模拟来预测低氧化度下GO的结构和电子性质，并建议对Lerf-Klinowski模型进行修正。我们发现，对于含有高浓度环氧基团的样品，层变形更大，相应地带隙也会增加。对GO表面进行有针对性的化学修饰似乎是为特定应用定制单层电子性质的有效途径。我们的模拟还表明，C-1s XPS峰的化学位移能够明确地表征GO的组成，解决了实验中经常遇到的峰归属不确定性问题。
