Carbon–Heteroatom Bond Formation by an Ultrasonic Chemical Reaction for Energy Storage Systems

The direct formation of CN and CO bonds from inert gases is essential for chemical/biological processes and energy storage systems. However, its application to carbon nanomaterials for improved energy storage remains technologically challenging. A simple and very fast method to form CN and CO bonds in reduced graphene oxide (RGO) and carbon nanotubes (CNTs) by an ultrasonic chemical reaction is described. Electrodes of nitrogen‐ or oxygen‐doped RGO (N‐RGO or O‐RGO, respectively) are fabricated via the fixation between N2 or O2 carrier gas molecules and ultrasonically activated RGO. The materials exhibit much higher capacitance after doping (133, 284, and 74 F g−1 for O‐RGO, N‐RGO, and RGO, respectively). Furthermore, the doped 2D RGO and 1D CNT materials are prepared by layer‐by‐layer deposition using ultrasonic spray to form 3D porous electrodes. These electrodes demonstrate very high specific capacitances (62.8 mF cm−2 and 621 F g−1 at 10 mV s−1 for N‐RGO/N‐CNT at 1:1, v/v), high cycling stability, and structural flexibility.