Controlled Nitrogen Doping of Graphene Quantum Dots through Laser Ablation in Aqueous Solutions for Photoluminescence and Electrocatalytic Applications
Controlled Nitrogen Doping of Graphene Quantum Dots through Laser Ablation in Aqueous Solutions for Photoluminescence and Electrocatalytic Applications
复制标题
DOI：
10.1021/acsanm.9b01433
复制
发表时间：
2019-11-01
影响因子：
5.9
通讯作者：
Kim, Doo Young
中科院分区：
文献类型：
--
作者：
Calabro, Rosemary L.;Yang, Dong-Sheng;Kim, Doo Young
氮掺杂石墨烯量子点(N-GQD)在催化和光致发光方面具有广阔的应用前景，但现有的许多合成方法需要使用苛刻的化学物质，反应时间长，纯化步骤复杂，对表面官能团的控制较差。液体中激光烧蚀(LAL)制备纳米材料具有生产速度快、化学药品用量少、提纯简单、副产物少等优点，并通过精确调节激光烧蚀参数来控制产物，是一种很有前途的制备纳米材料的方法。我们报道了使用LAL从碳纳米洋葱在氨、乙二胺和吡啶的水溶液中制备N-GQD。选择这些掺杂剂可以调节总的氮含量和官能团的分布，从而控制光致发光发射波长和寿命。高浓度的胺基团会使发射红移，寿命变短，而吡啶基团会蓝移发射，寿命较长。N-GQD还表现出了良好的电催化性能，用于将氧气还原为过氧化氢，这是一种广泛应用于工业应用的重要化学品。N-GQD表现出低过电位和高选择性的两电子氧还原途径。
Nitrogen-doped graphene quantum dots (N-GQDs) have promising applications in catalysis and photoluminescence, but many existing synthetic methods require uses of harsh chemicals, long reaction times, and complicated purification steps and have poor control over the surface functional groups. Laser ablation in liquid (LAL) is a promising alternative method to prepare nanomaterials because of its fast production, use of fewer chemicals, simple purification, and fewer byproducts and its control of the product by precise tuning of laser ablation parameters. We report the use of LAL to produce N-GQDs from carbon nano-onions in aqueous solutions of ammonia, ethylenediamine, and pyridine. The choice of these dopants allowed for tuning the overall nitrogen content and the distribution of functional groups that led to the control over the photoluminescence emission wavelengths and lifetimes. High concentrations of amine groups tended to red-shift emission and exhibit shorter lifetimes, whereas pyridinic groups would blue-shift the emission and exhibit longer lifetimes. The N-GQDs also showed a promising performance as electrocatalysts for reducing oxygen to hydrogen peroxide, an important chemical widely used in industrial applications. The N-GQDs exhibited both low overpotentials and high selectivity for a two-electron oxygen reduction pathway.