对sp2碳表面的二氧化变异的空间和时间控制
Paul M Kirkman1, Aleix G Güell, Anatolii S Cuharuc
1Department of Chemistry, University of Warwick , Gibbet Hill Road, Coventry, CV4 7AL, U.K.
Journal of the American Chemical Society
|December 12, 2013
概括
使用扫描电化学细胞显微镜 (SECCM) 实现了sp(2) 碳材料的受控化学功能化. 这种方法允许精确的,微米级的迪亚佐尼修饰,用于先进的材料应用.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 表面化学 表面化学
背景情况:
- 对sp(2) 碳材料,特别是石墨烯的受控化学功能化对于调整带隙生成等电子性质至关重要.
- 化合物为修改sp(2) 碳表面提供了一种多功能途径,但实现精确的空间控制仍然是一个挑战.
研究的目的:
- 用微米尺度的精度来证明sp(2) 碳表面的局部二氧化修饰.
- 通过扫描电化学细胞显微镜 (SECCM) 来研究电化学驱动的二氧化图案.
- 探索电化学驱动力对薄膜密度,sp(2) /sp(3) 重杂化和多层形成的影响.
主要方法:
- 使用扫描电化学细胞显微镜 (SECCM) 在sp(2) 碳表面上进行局部电化学反应.
- 采用原子力显微镜 (AFM) 和拉曼光谱来进行详细的表面表征.
- 研究不同电化学驱动力对二氧化功能化的影响.
主要成果:
- 实现了高度控制的微米尺度的二氧化修饰原始的sp(2) 碳表面.
- 证明了控制薄膜密度,sp2 / sp3重混合的程度和多层形成的能力.
- 建立了电化学驱动力和表面修饰程度之间的相关性.
结论:
- 通过SECCM进行局部电化学提供了一条强大的途径,用于对sp(2) 碳材料进行受控的二氧化碳修饰.
- 这种技术可以实现精确的图案,为量身定制的材料特性铺平道路,例如石墨烯的带隙工程.
- 这些发现为制造具有所需电子和化学特性的功能性碳基纳米材料开辟了新的途径.
相关概念视频
01:19Diazonium Group Substitution: –OH and –H
1.9K
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.
1.9K
01:14Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
2.1K
Treating arylamines with nitrous acid gives aryldiazonium salts that are effective substrates in nucleophilic aromatic substitution reactions. The diazonio group in these salts can be easily displaced by different nucleophiles, yielding a wide variety of substituted benzenes. The leaving group departs as nitrogen gas, and this easy elimination is the driving force for the substitution reaction.
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
2.1K
01:371° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
3.3K
Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.
3.3K
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
2.0K
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...
2.0K
01:11Aryldiazonium Salts to Azo Dyes: Diazo Coupling
3.2K
The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the...
3.2K
01:33Carboxylic Acids to Methylesters: Alkylation using Diazomethane
2.3K
Carboxylic acids react with diazomethane in an ether solvent via alkylation at the carboxylate oxygen atom to give methyl esters of the corresponding acid with excellent yields.
2.3K