One-pot synthesis of lightweight nitrogen-doped graphene hydrogels with supercapacitive properties

• A facile and efficient synthesis of lightweight nitrogen-doped graphene hydrogels (NGHs).
• NGHs with good capacitive behavior and superior cycling stability.
• The possible mechanism of assembly process of NGHs and the N insertion pathway were proposed.

A facile and efficient method was developed to prepare nitrogen-doped graphene hydrogels (NGHs) via a one-pot hydrothermal route with graphene oxide (GO) and urea. In the procedure, urea was used as a reducing-doping agent to continuously release NH3, and N element of which was doped into graphene lattice by three styles (pyridinic N, pyrrolic N, and graphitic/quaternary N). The NGHs have high nitrogen content (ca. 6.04–6.84%), lightweight nature (the density of hydrogel is ca. 0.81–0.94 g cm−3), and numerous interconnected three dimensional porous networks. Electrochemical characterizations demonstrated the good capacitive behavior (230.6 F g−1, at 0.5 A g−1) and superior cycling stability (capacitance retention ∼90% after 1200 cycles) of NGHs. The possible mechanism of assembly process of NGHs and the N insertion pathway in the hydrothermal route were also proposed.

A facile and efficient method was developed to prepare nitrogen-doped graphene hydrogels with supercapacitive properties via a one-pot hydrothermal route.Figure optionsDownload as PowerPoint slide