当前位置: X-MOL 学术Synth. Met. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Band structure, work function and interfacial diagrams of oxygen-functionalized carbon nano-onions
Synthetic Metals ( IF 4.0 ) Pub Date : 2020-08-01 , DOI: 10.1016/j.synthmet.2020.116434
Julio C. Zuaznabar-Gardona , Alex Fragoso

Abstract Carbon nano-onions (CNOs) are an emerging class of carbon nanomaterials with a wide range of applications. Few is known about their electronic structure and the factors that affect it. Here, we study for the first time the effect of two oxidation treatments on the electronic structure of CNOs using ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS). CNOs were oxidized by physical (Ar/O2 radio frequency plasma) and chemical (HNO3/H2SO4) methods. It was found that the physical oxidative treatment introduced preferentially hydroxyl and carbonyl groups on the outer shells of CNOs and changed the electronic state from metallic to semiconductor with a work function of 4.3 eV and a valence band located 0.2 eV below the Fermi level. In contrast, the chemical oxidation produced CNOs with hydroxyl and carboxylic acid moieties and increased the work function from 4.3 to 4.8 eV with preservation of the metallic structure of CNO. The variations on the electronic structure were explained in terms of the elimination/generation of structural defects on the outer shells of CNO and the electronic effects that resulted from the introduction of different oxygen-containing functional groups on the graphitic layers. The interfacial energy diagrams for pristine and oxidized CNOs were constructed from the UPS data. These diagrams can be used to explain electronic interfacial properties of these materials and the design of novel electrochemical or photovoltaic devices.

中文翻译:

氧功能化碳纳米洋葱的能带结构、功函数和界面图

摘要 碳纳米洋葱(CNOs)是一类新兴的碳纳米材料,具有广泛的应用前景。人们对它们的电子结构及其影响因素知之甚少。在这里,我们首次使用紫外光电子能谱 (UPS) 和 X 射线光电子能谱 (XPS) 研究了两种氧化处理对 CNOs 电子结构的影响。CNOs 被物理(Ar/O2 射频等离子体)和化学(HNO3/H2SO4)方法氧化。发现物理氧化处理优先在 CNOs 的外壳上引入羟基和羰基,并将电子态从金属态变为半导体态,功函数为 4.3 eV,价带位于费米能级以下 0.2 eV。相比之下,化学氧化产生了具有羟基和羧酸部分的 CNO,并将功函数从 4.3 eV 增加到 4.8 eV,同时保留了 CNO 的金属结构。电子结构的变化可以从 CNO 外壳上结构缺陷的消除/产生以及由于在石墨层上引入不同的含氧官能团而产生的电子效应来解释。原始和氧化 CNO 的界面能图是根据 UPS 数据构建的。这些图表可用于解释这些材料的电子界面特性以及新型电化学或光伏器件的设计。电子结构的变化可以从 CNO 外壳上结构缺陷的消除/产生以及由于在石墨层上引入不同的含氧官能团而产生的电子效应来解释。原始和氧化 CNO 的界面能图是根据 UPS 数据构建的。这些图表可用于解释这些材料的电子界面特性以及新型电化学或光伏器件的设计。电子结构的变化可以从 CNO 外壳上结构缺陷的消除/产生以及由于在石墨层上引入不同的含氧官能团而产生的电子效应来解释。原始和氧化 CNO 的界面能图是根据 UPS 数据构建的。这些图表可用于解释这些材料的电子界面特性以及新型电化学或光伏器件的设计。原始和氧化 CNO 的界面能图是根据 UPS 数据构建的。这些图表可用于解释这些材料的电子界面特性以及新型电化学或光伏器件的设计。原始和氧化 CNO 的界面能图是根据 UPS 数据构建的。这些图表可用于解释这些材料的电子界面特性以及新型电化学或光伏器件的设计。
更新日期:2020-08-01
down
wechat
bug