Abstract
The unique properties of holey graphene sheet, referred to graphene sheet with nanoholes in its basal plane, lead to wide range of applications, which cannot be achieved by its nonporous counterpart. However, its large scale solution based production requires graphene oxide (GO) or reduced GO (rGO) as starting materials, which take hours to days for their fabrication. Here, we report our 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. 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 toward electrochemical oxygen reduction reaction. The existence of the nanoholes not only provides a “short cut” for efficient mass transport, but also 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 us to develop efficient catalyst, which can replace previous coin metals for energy generation and storage, such as fuel cells and metal–air batteries