Ulsan National Institute of Science and Technology (UNIST), Interdisciplinary School of Green Energy/Low-Dimensional Carbon Materials Center, 100 Banyeon, Ulsan 689-897, South Korea.
J Am Chem Soc. 2013 Jan 30;135(4):1386-93. doi: 10.1021/ja3091643. Epub 2012 Nov 12.
Edge-selectively functionalized graphene nanoplatelets (EFGnPs) with different functional groups were efficiently prepared simply by dry ball milling graphite in the presence of hydrogen, carbon dioxide, sulfur trioxide, or carbon dioxide/sulfur trioxide mixture. Upon exposure to air moisture, the resultant hydrogen- (HGnP), carboxylic acid- (CGnP), sulfonic acid- (SGnP), and carboxylic acid/sulfonic acid- (CSGnP) functionalized GnPs readily dispersed into various polar solvents, including neutral water. The resultant EFGnPs were then used as electrocatalysts for oxygen reduction reaction (ORR) in an alkaline electrolyte. It was found that the edge polar nature of the newly prepared EFGnPs without heteroatom doping into their basal plane played an important role in regulating the ORR efficiency with the electrocatalytic activity in the order of SGnP > CSGnP > CGnP > HGnP > pristine graphite. More importantly, the sulfur-containing SGnP and CSGnP were found to have a superior ORR performance to commercially available platinum-based electrocatalyst.
通过在氢气、二氧化碳、三氧化硫或二氧化碳/三氧化硫混合物存在的情况下，干法球磨石墨，可高效制备具有不同官能团的边缘选择性功能化石墨烯纳米片（EFGnPs）。在暴露于空气湿度时，所得的氢（HGnP）、羧酸（CGnP）、磺酸（SGnP）和羧酸/磺酸（CSGnP）功能化 GnPs 很容易分散到各种极性溶剂中，包括中性水。然后，将所得的 EFGnPs 用作碱性电解质中氧还原反应（ORR）的电催化剂。结果发现，新制备的 EFGnPs 具有边缘极性，而其基面中没有杂原子掺杂，这对调节 ORR 效率起着重要作用，其电催化活性顺序为 SGnP > CSGnP > CGnP > HGnP > 原始石墨。更重要的是，含硫的 SGnP 和 CSGnP 被发现具有优于市售基于铂的电催化剂的 ORR 性能。
