Microwave Enabled One‐Pot, One‐Step Fabrication and Nitrogen Doping of Holey Graphene Oxide for Catalytic Applications

Abstract

The unique properties of a holey graphene sheet, referred to as a graphene sheet with nanoholes in its basal plane, lead to wide range of applications that cannot be achieved by its nonporous counterpart. However, the large-scale solution-based production requires graphene oxide (GO) or reduced GO (rGO) as the starting materials, which take hours to days for fabrication. Here, an unexpected discovery that GO with or without holes can be controllably, directly, and rapidly (tens of seconds) fabricated from graphite powder via a one-step-one-pot microwave assisted reaction with a production yield of 120 wt% of graphite is reported. Furthermore, a fast and low temperature approach is developed for simultaneous nitrogen (N) doping and reduction of GO sheets. The N-doped holey rGO sheets demonstrate remarkable electrocatalytic capabilities for the electrochemical oxygen reduction reaction. The existence of the nanoholes provides a "short cut" for efficient mass transport and dramatically increases edges and surface area, therefore, creates more catalytic centers. The capability of rapid fabrication and N-doping as well as reduction of holey GO can lead to development of an efficient catalyst that can replace previous coin metals for energy generation and storage, such as fuel cells and metal-air batteries.

Porous Carbon/rGO Composite: An Ideal Support Material of Highly Efficient Palladium Electrocatalysts for the Formic Acid Oxidation Reaction

“…Peaks centered at binding energies between 284–285 eV are mostly assigned to graphitic or sp 2 carbon species in aromatic rings. Peaks centered in the region of binding energy (286–292 eV) are usually assigned to oxygenated organic species such as hydroxyl, epoxide and carboxylic entities and peaks at 283 eV are assigned to metal carbide bond . The assignment of various peaks depending upon the nature of carbon is as follows; C=C (284.8 eV) C−C bonds (285.28 eV), C−OH/C−O−C/O−C=O bonds (287.07 eV), C=O/O−C−O (288.51 eV) C=O−COO bonds (291.68 eV).…”

Improved Li+ Storage through Homogeneous N‐Doping within Highly Branched Tubular Graphitic Foam

“…We consider that more N heteroatom doping would be beneficial for relieving internal stresses between the curved planes and inside each bent layer. As shown in Figure b, four fitted peaks in a high‐resolution XPS N 1s spectrum are assigned to the typical pyridinic N (N 1 , 398.3 eV), pyrrolic N (N 2 , 400.6 eV), graphitic or quaternary N (N 3 , 402 eV), and oxidic N (N 4 , 403.2 eV), respectively . N 1 , N 2 , and N 3 doping sites are located at the edges and/or hole defect sites of NG (0002) layer, as presented in Figure c.…”

Core/Shell NiFe Nanoalloy with a Discrete N‐doped Graphitic Carbon Cover for Enhanced Water Oxidation

“…In being different from the thermally stable NiFe 2 O 4 , Fe‐doped NiO possessed more alien dopants and structural defects, making it easy to react with urea. In addition, the oxygen and nitrogen functional groups could provide sites for urea adsorption …”